JP2012180424A - Xylan derivative precursor, xylan derivative, xylan graft copolymer, method of producing these, and polymer molded product - Google Patents

Abstract

A xylan derivative that can effectively utilize unused biomass and can be used as a plastic material, a method for producing the xylan derivative, a precursor of the xylan derivative and a method for producing the xylan derivative, a method for producing the xylan graft copolymer, and a method for producing the polymer Provided.
A xylan derivative precursor in which at least one of the hydrogen atoms of a hydroxyl group in a xylan having a structural unit represented by the following structural formula (1) is substituted with a halogen-containing group or a substituent having an azide group; PRODUCTION METHOD, XYLAN GRAFT COPOLYMER, PRODUCTION METHOD THEREOF, AND POLYMER MOLDED BODY.

[Selection] Figure 5

Description

  The present invention relates to a xylan derivative precursor, a xylan derivative, a xylan graft copolymer, a production method thereof, and a polymer molded body.

  The majority of plastic materials are based on oil, but it is an alternative from the viewpoint of environmental protection, such as limited fossil resources, increasing the greenhouse effect through incineration, and the fact that petroleum-based plastic materials cannot generally be decomposed. Material is desired.

Cellulose has long been used as an industrial material, converted into a thermoplastic by esterification or etherification, and used as a film or fiber.
Generally, wood is composed of 40% by mass of cellulose, 30% by mass of hemicellulose, and 30% by mass of lignin. Therefore, not only cellulose but also hemicellulose is a promising resource as a biological material.

Xylan, which is the most abundant component in hemicellulose in wood such as conifers and broad-leaved trees, and herbs such as pasture, is a natural polysaccharide.
However, hemylcellulose containing xylan is difficult to use as a polymer material due to its low molecular weight, and has many branched structures and several sugars that are complexly bound. In the past, it has been discarded without being used as a material such as plastic because it is difficult to make a homogeneous material.
Although there are few studies on derivatization of hemicellulose with alkyl groups (see Non-Patent Documents 1 and 2), structural control is insufficient such as low substitution degree, and plastic materials have not been made.

  Accordingly, the present situation is that there is a strong demand for the provision of a xylan derivative that can effectively use unused biomass that has not been recognized for its value and can be used as a plastic material.

Sun, R.A. C. Fang, J .; M.M. Tomkinson, J .; Jones, G .; L. , Industrial Crops And Products, 1999, 10, 209-218. Fang, J .; M.M. Sun, R .; C. Fowler, P .; Tomkinson, J .; Hill, C .; A. S. , Journal Of Applied Polymer Science, 1999, 74, 2301-2311.

  An object of the present invention is to solve the above-described problems and achieve the following objects. That is, the present invention relates to a xylan derivative that can effectively use unused biomass and can be used as a plastic material and a method for producing the xylan derivative, a precursor of the xylan derivative and a method for producing the xylan derivative, a method for producing the xylan graft copolymer, and a method for producing the polymer. It aims at providing a molded object.

  In order to use hemicellulose as a plastic material, it is necessary to appropriately protect a free hydroxyl group with a substituent and solubilize it in a general-purpose organic solvent, or to impart thermoplasticity to improve moldability. In addition, when derivatizing an unmodified sugar chain, the reaction proceeds relatively easily in the case of a low molecular weight substituent such as an alkyl group, but in the case of a high molecular weight substituent such as a polymer, the reaction proceeds efficiently. It is difficult to progress.

  Therefore, in order to solve the above-mentioned problems, the present inventors have earnestly studied and as a result, obtained the following knowledge. That is, a xylan derivative in which at least one of the hydrogen atoms of a hydroxyl group in a xylan having a structural unit represented by the following structural formula (1) is substituted with a substituent having an azide group can effectively utilize unused biomass. The present invention has been completed by finding that it can be used as a plastic material.

The present invention is based on the above findings by the present inventors, and means for solving the above problems are as follows. That is,
<1> A xylan derivative precursor in which at least one of hydrogen atoms of a hydroxyl group in a xylan having a structural unit represented by the following structural formula (1) is substituted with a halogen-containing group.
However, in the structural formula (1), n represents the degree of polymerization.
<2> The xylan derivative precursor according to <1>, wherein a substitution degree of a hydroxyl group to a hydrogen atom in a monomer unit of xylan is 2.
<3> A method for producing a xylan derivative precursor, comprising producing a xylan derivative precursor by reacting a xylan having a structural unit represented by the following structural formula (1) with a halogen-containing compound. .
However, in the structural formula (1), n represents the degree of polymerization.
<4> A xylan derivative characterized in that at least one of the hydrogen atoms of a hydroxyl group in a xylan having a structural unit represented by the following structural formula (1) is substituted with a substituent having an azide group.
However, in the structural formula (1), n represents the degree of polymerization.
<5> The xylan derivative according to <4>, wherein the substitution degree of the hydroxyl group to the hydrogen atom in the xylan monomer unit is 2.
<6> A xylan derivative is produced by reacting the xylan derivative precursor according to any one of <1> to <2> above with a compound that substitutes a halogen group of a halogen-containing group with an azide group. And a method for producing a xylan derivative.
<7> A method for producing a xylan graft copolymer, comprising reacting a compound having an alkyne at a terminal with the xylan derivative according to any one of <4> to <5>.
<8> The method for producing a xylan graft copolymer according to <7>, wherein the compound having an alkyne at a terminal is a polymer having a propargyl group.
<9> A xylan graft copolymer obtained by the method for producing a xylan graft copolymer according to any one of <7> to <8>, having a xylan derivative as a main chain and a polymer as a side chain. .
<10> A polymer molded article comprising at least one of the xylan derivative according to any one of <4> to <5> and the xylan graft copolymer according to <9>.
<11> The polymer molded article according to <10>, which is a film.

  According to the present invention, the conventional problems can be solved, the object can be achieved, unused biomass can be used effectively, and a xylan derivative that can be used as a plastic material, a method for producing the xylan derivative, A precursor and a production method thereof, a xylan graft copolymer and a production method thereof, and a polymer molded body can be provided.

FIG. 1 is a proton nuclear magnetic resonance spectrum of di-O- (6-bromohexanoyl) -xylan, which is an example of the xylan derivative precursor of the present invention. FIG. 2 is a carbon nuclear magnetic resonance spectrum of di-O- (6-bromohexanoyl) -xylan, which is an example of the xylan derivative precursor of the present invention. FIG. 3 is a proton nuclear magnetic resonance spectrum of di-O- (6-azidohexanoyl) -xylan, which is an example of the xylan derivative of the present invention. FIG. 4 is a carbon nuclear magnetic resonance spectrum of di-O- (6-azidohexanoyl) -xylan, which is an example of the xylan derivative of the present invention. FIG. 5 is a proton nuclear magnetic resonance spectrum of di-O- (6-azidohexanoyl) -xylan-graft-poly L-lactide, which is an example of the graft copolymer of the present invention. FIG. 6A is a carbon nuclear magnetic resonance spectrum of di-O- (6-azidohexanoyl) -xylan-graft-poly L-lactide, which is an example of the graft copolymer of the present invention. FIG. 6B is an enlarged view of FIG. 6A. FIG. 6C is an enlarged view of FIG. 6B. FIG. 7 is a proton nuclear magnetic resonance spectrum of terminal propargylated poly L-lactide, which is an example of a compound having an alkyne used in the method for producing a graft copolymer of the present invention. FIG. 8 is a carbon nuclear magnetic resonance spectrum of terminal propargylated poly L-lactide, which is an example of a compound having an alkyne used in the method for producing a graft copolymer of the present invention. FIG. 9 is a photograph of the film produced in Example 4.

(Xylan derivative precursor and method for producing the same)
The xylan derivative precursor of the present invention is a compound in which at least one of hydrogen atoms of a hydroxyl group in xylan having a structural unit represented by the following structural formula (1) is substituted with a halogen-containing group.
The method for producing a xylan derivative precursor of the present invention is a method for producing a xylan derivative precursor by reacting a xylan having a structural unit represented by the following structural formula (1) with a halogen-containing compound. is there.
Hereinafter, the manufacturing method of this xylan derivative precursor is demonstrated with description of a xylan derivative precursor.
However, in the structural formula (1), n represents the degree of polymerization. There is no restriction | limiting in particular as said n, Although it can select suitably according to the objective, 10-500 are preferable and 40-500 are more preferable.

<Xylan derivative precursor>
The halogen-containing group in the xylan derivative precursor is not particularly limited and may be appropriately selected according to the type of halogen-containing compound to be reacted with xylan in the method for producing the xylan derivative precursor, for example And a substituent having a halogen group at the terminal of a linear or branched alkyl group which may have a substituent.
There is no restriction | limiting in particular as carbon number of the said alkyl group, Although it can select suitably according to the objective, 2-20 are preferable and 2-6 are more preferable.

  Specific examples of the halogen-containing group include 6-bromohexanoyl group, 5-bromovaleryl group, 8-bromooctanoyl group, 11-bromoundecanoyl group, 16-bromohexadecanoyl group, 5-chlorovaleryl group and the like. Is mentioned.

The degree of substitution of the halogen-containing group in the hydrogen atom of the hydroxyl group of the xylan is not particularly limited and may be appropriately selected depending on the intended purpose. The xylan derivative precursor is a general-purpose organic material such as chloroform or dimethylformamide. It is preferably substituted in a solvent-soluble range, the substitution degree is more preferably 1 to 2 and particularly preferably 2 with respect to the hydrogen atom of the hydroxyl group in the xylan monomer unit.
In the xylan derivative precursor, a hydrogen atom of a hydroxyl group of at least one structural unit in the polymer of xylan may be substituted with a halogen-containing group, but a hydrogen atom of a hydroxyl group in two or more structural units Is preferably substituted with a halogen-containing group.
The method for measuring the degree of substitution is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include elemental analysis, proton nuclear magnetic resonance, carbon nuclear magnetic resonance, and infrared spectroscopy. Can be mentioned.

There is no restriction | limiting in particular as a number average molecular weight of the said xylan derivative precursor, Although it can select suitably according to the objective, 5,000-240,000 are preferable at polystyrene (PS) conversion, 20,000- 240,000 is more preferred.
The number average molecular weight can be measured by gel permeation chromatography (GPC method), viscosity method, terminal group quantification method, light scattering method and the like.

  Specific examples of the xylan derivative precursor include di-O- (6-bromohexanoyl) -xylan, di-O- (5-bromovaleryl) xylan, di-O- (8-bromooctanoyl) xylan, di- -O- (11-bromoundecanoyl) xylan, di-O- (16-bromohexadecanoyl) xylan, di-O- (5-chlorovaleryl) xylan and the like can be mentioned.

Among these, the xylan derivative precursor is preferably a compound represented by the following structural formula (2) in which a hydrogen atom of a hydroxyl group in xylan is substituted with a 6-bromohexanoyl group.
However, in the structural formula (2), x represents the degree of polymerization, and R ₁ and R ₂ represent either a substituent represented by the following structural formula (A) or a hydrogen atom. However, in the polymer having the structural unit represented by the structural formula (2), at least one of the R ₁ and R ₂ of at least one structural unit is a substituent represented by the following structural formula (A). It is.
Among these, R ₁ and R ₂ are all di-O- (6-bromohexanoyl) -xylan (hereinafter referred to as “XylC6Br”) which is a substituent represented by the following structural formula (A). Is particularly preferred.
There is no restriction | limiting in particular as said x, Although it can select suitably according to the objective, 10-500 are preferable and 40-500 are more preferable.

  The physicochemical properties of the XylC6Br are as follows. Here, the physicochemical properties of XylC6Br having a polymerization degree x of 44.0 are shown as an example, but the xylan derivative precursor of the present invention is not limited to this.

-Physicochemical properties of XylC6Br-
(1) Property: Solid (2) Molecular weight: Number average molecular weight (Mn) is 21,400, weight average molecular weight (Mw) is 37,600, and Mw / Mn is 1.76.
(3) The proton nuclear magnetic resonance spectrum measured under conditions of 500 MHz and 25 ° C. in deuterated chloroform is as shown in FIG. 1, and the chart is as follows.
_{^{1 H-NMR (CDCl 3)}} : δ1.44 (m, 2H, -C H 2 -CH 2 -CH 2 -Br), 1.59 (m, 2H, -CO-CH 2 -C H 2 -) _{, 1.77 (m, 2H, -C} H 2 -CH 2 -Br), 2.26 (s, 2H, -CO-CH 2 -), 3.23 (C5-Ha), 3.54 (t _{, 2H, J = 6.5, -CH} 2 -Br), 3.76 (C4-H), 3.89 (C5-He), 4.43 (C1-H), 4.69 (C2-H ), 5.00 (C3-H).
(4) The carbon nuclear magnetic resonance spectrum measured under conditions of 500 MHz and 25 ° C. in deuterated chloroform is as shown in FIG. 2, and the chart is as follows.
_{^{13 C-NMR (CDCl 3)}} : δ24.0 (-CO-CH 2 - C H 2 -), 26.3 (- C H 2 -CH 2 -CH 2 -Br), 32.1 (- C H _{2 -CH 2 -Br), 33.7 (} -CO- C H 2 -), 44.8 (-CH 2 -Br), 62.5 (C5), 70.7 (C2), 71.7 ( C3), 74.2 (C4), 99.9 (C1), 171.7, 172.2 (CO of C2 and C3, representatively).
In ¹ H-NMR and ¹³ C-NMR, chemical shift (δ) and coupling constant (J) indicate “ppm” and “Hz”.

<Method for producing xylan derivative precursor>
The method for producing a xylan derivative precursor of the present invention includes at least a step of reacting the xylan represented by the structural formula (1) with a halogen-containing compound, and further includes other steps as necessary.

<< xylan >>
There is no restriction | limiting in particular as a weight average molecular weight of the said xylan, Although it can select suitably according to the objective, 8,000 or more are preferable, 10,000 or more are more preferable, and 12,000 or more are especially preferable. As the xylan is a polymer, a xylan derivative produced using the xylan is preferable in that it easily forms a plastic material.

  The method for confirming the weight average molecular weight of the xylan is not particularly limited and may be appropriately selected depending on the intended purpose. However, the xylan has a polysaccharide structure represented by the structural formula (1). And insoluble in organic solvents, it is difficult to measure directly. Therefore, for example, there is a method of measuring the weight average molecular weight of the xylan derivative and calculating from the weight average molecular weight of the xylan derivative.

  There is no restriction | limiting in particular as a measuring method of the weight average molecular weight of the said xylan derivative, It can select suitably from well-known methods, for example, a gel permeation chromatography method (GPC method), a viscosity method, terminal group determination. Method, light scattering method, and the like.

-Extraction method of xylan-
There is no restriction | limiting in particular as a xylan origin raw material, Although it can select suitably according to the objective, A xylan derived from a pulp raw material is preferable at the point which can utilize an unused biomass effectively.
The method for obtaining the xylan from the pulp raw material is not particularly limited and may be appropriately selected according to the purpose, but preferably includes an alkali extraction step, and if necessary, a pH adjustment step, a precipitation step, Other processes such as a washing process, a filtration process, and a drying process are included.
Xylan, which is hemicellulose, is distinguished from cellulose in that it can be extracted with an aqueous alkaline solution. Like water, water is insoluble in general-purpose organic solvents.

--Alkali extraction process--
The pulp raw material is not particularly limited and may be appropriately selected according to the purpose. However, it is preferable to use a material extracted from a biomass raw material, and extracted from raw materials such as wood, herbs, straw, bamboo, etc. It is preferred that These may be used alone or in combination of two or more. Among these, wood is preferable in that it contains a large amount of the xylan. There is no restriction | limiting in particular as said wood, According to the objective, it can select suitably, For example, a hardwood raw material, a conifer raw material, etc. are mentioned.

  The pulp raw material is preferably preliminarily cut from the viewpoint that xylan can be efficiently extracted. There is no restriction | limiting in particular as a method of cutting the said pulp raw material, According to the objective, it can select suitably, For example, a Willet mill, a cutter mill, a hammer mill, a pin mill etc. are mentioned. In addition, as the said pulp raw material, you may use the commercial item already cut | judged.

  There is no restriction | limiting in particular as said alkaline solution, According to the objective, it can select suitably, For example, sodium hydroxide aqueous solution, potassium hydroxide aqueous solution, ammonia aqueous solution etc. are mentioned. These may be used alone or in combination of two or more. Among these, the alkaline solution is preferably a sodium hydroxide aqueous solution.

There is no restriction | limiting in particular as a density | concentration of the said alkaline solution, Although it can select suitably according to the objective, 5 mass% or more is preferable and 16 mass% or more is more preferable. When the concentration of the alkaline solution is less than 5% by mass, the recovery rate of xylan may be deteriorated, or high-molecular xylan may not be obtained. On the other hand, when the concentration of the alkaline solution is 16% by mass or more, the recovery rate of the xylan is improved, and a high molecular xylan can be obtained.
There is no restriction | limiting in particular as an upper limit of the density | concentration of the said alkaline solution, According to the objective, it can select suitably.

There is no restriction | limiting in particular as time to perform the said alkali extraction, Although it can select suitably according to the objective, 10 hours or more are preferable and 16 hours or more are still more preferable. When the alkali extraction time is less than 10 hours, the recovery rate of xylan may deteriorate.
There is no restriction | limiting in particular as an upper limit of the said alkali extraction time, According to the objective, it can select suitably.

  The amount of the alkali solution used can be appropriately selected depending on the amount of pulp raw material to be used, the size of the processing container, and the like. 100 parts by mass to 320 parts by mass is more preferable. When the amount of the alkaline solution used is less than 20 parts by mass, the recovery rate of the xylan may deteriorate, and when it exceeds 400 parts by mass, the alkali concentration is too high, which is disadvantageous in cost.

--PH adjustment process--
The pH adjusting step is a step of adjusting the pH of the reaction solution containing xylan after the alkali extraction.
There is no restriction | limiting in particular as said pH, Although it can select suitably according to the objective, 5-8 are preferable and 6-7 are more preferable. If the pH is out of the preferred range, a precipitate containing xylan may not be obtained in the precipitation step described later.
There is no restriction | limiting in particular as a reagent used for the said pH adjustment, Although it can select suitably according to the objective, Acids, such as hydrochloric acid, acetic acid, formic acid, are preferable.
There is no restriction | limiting in particular as the method of measuring the said pH, It can select suitably from well-known methods.

-Precipitation process-
The said precipitation process is a method of precipitating the xylan contained in the reaction liquid after the said alkali extraction, and also the reaction liquid which passed through the said pH adjustment process as needed. It is preferable that the xylan production method includes the precipitation step in that the recovery rate of the xylan is improved.
There is no restriction | limiting in particular as said precipitation process, According to the objective, it can select suitably, For example, the method of adding lower alcohols, such as ethanol and methanol, etc. are mentioned.
There is no restriction | limiting in particular as the usage-amount of the said lower alcohol, Although it can select suitably according to the objective, 2 times volume-10 times volume are preferable with respect to the said alkali extract, 5 times volume-10 times. Capacity is more preferred. If the amount of the lower alcohol used is less than 2 times the volume, the xylan precipitation efficiency may be deteriorated, and if it exceeds 10 times the volume, it is disadvantageous in terms of cost.
There is no restriction | limiting in particular as temperature to make the said precipitation, Although it can select suitably according to the objective, It is preferable to carry out at low temperature and 0 to 25 degreeC is more preferable.
There is no restriction | limiting in particular as time to make the said precipitation, Although it can select suitably according to the objective, 0.5 to 24 hours are preferable and 0.5 to 6 hours are more preferable.

-Cleaning process-
The washing step is a step of washing the reaction solution containing xylan obtained by the alkali extraction and, if necessary, the reaction solution that has undergone the pH adjustment step and the precipitation step.
There is no restriction | limiting in particular as a solution used for the said washing | cleaning, According to the objective, it can select suitably, For example, ethanol, methanol, etc. are mentioned. These may be used alone or in combination of two or more.
The washing method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of mixing the reaction solution and the washing solvent and centrifuging, a method using a column, and the like. Can be mentioned.
There is no restriction | limiting in particular as the frequency | count of washing | cleaning, According to the objective, it can select suitably.

-Filtration process-
In the filtration step, the reaction solution containing xylan obtained by the alkali extraction and, if necessary, the reaction solution that has undergone the pH adjustment step, the precipitation step, and the washing step are filtered to remove unnecessary substances. It is a process. Moreover, the said filtration process may be performed simultaneously with the said washing | cleaning process.
The method for performing the filtration is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include a method of centrifugation, a method of using a column, a method of using a filter, and a method of using a known filtration device. Can be mentioned. These treatments may be performed singly or in combination of two or more.
It is preferable that the filtration step is performed both after the alkali extraction and after the precipitation step because xylan having a high degree of purification can be obtained.

--- Drying process--
The drying step is a step of drying the reaction solution containing xylan obtained by the alkali extraction, and further, if necessary, the reaction solution that has undergone the pH adjustment step, the precipitation step, the washing step, and the filtration step. is there.
There is no restriction | limiting in particular as the method of drying, It can select suitably from well-known methods, For example, a freeze-drying method, a warm air drying method, a spray drying method, a fluidized bed drying method etc. are mentioned.

<< Halogen-containing compound >>
The halogen-containing compound is not particularly limited as long as it has a halogen group, and can be appropriately selected according to the purpose. For example, a linear or branched alkyl group which may have a substituent Examples thereof include compounds having a halogen group at the end of the group.
There is no restriction | limiting in particular as carbon number of the said alkyl group, Although it can select suitably according to the objective, 2-20 are preferable and 2-6 are more preferable. These may be used alone or in combination of two or more.
A commercial item may be used for the said halogen-containing compound, and what was synthesize | combined by the well-known method may be used.

  Specific examples of the halogen-containing compound include 6-bromohexanoyl chloride, 5-bromovaleryl chloride, 8-bromooctanoyl chloride, 11-bromoundecanoyl chloride, 16-bromohexadecanoyl chloride, 5-chloro. Examples include valeryl chloride. These may be used alone or in combination of two or more.

<< Reaction between xylan and halogen-containing compound >>
There is no restriction | limiting in particular as the method of making the said xylan and the said halogen-containing compound react, According to the objective, it can select suitably. Here, “reaction” means that the hydrogen atom of the hydroxyl group of xylan is substituted with a halogen-containing group. Thereby, the xylan derivative precursor which has a halogen at the terminal of a substituent can be obtained.

The xylan is preferably dissolved in a solvent before reacting with the halogen-containing compound.
The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include dimethylacetamide and dimethylformamide. These may be used alone or in combination of two or more.

  There is no restriction | limiting in particular as melt | dissolution temperature which dissolves the said xylan in the said solvent, Although it can select suitably according to the objective, 25 to 120 degreeC is preferable and 100 to 120 degreeC is more preferable. When the melting temperature exceeds 120 ° C., alteration such as coloring of the solution may occur.

  There is no restriction | limiting in particular as melt | dissolution time which dissolves the said xylan in the said solvent, Although it can select suitably according to the objective, 0.5 to 24 hours are preferable, and 0.5 to 2 hours are more preferable. . If the dissolution time is less than 0.5 hours, the xylan may not be sufficiently dissolved.

  There is no restriction | limiting in particular as addition amount of the said halogen-containing compound, Although it can select suitably according to the objective, 2 equivalent-4 equivalent are preferable with respect to the monomer unit of a xylan (anhydrous), and 3 equivalent-4 equivalent The equivalent is more preferable. If the addition amount is less than 2 equivalents, the hydrogen atom of the hydroxyl group of xylan may not be substituted with a halogen-containing group, and the degree of substitution may be insufficient, even if it exceeds 4 parts by mass, it is more The reaction rate does not increase and is disadvantageous in terms of cost.

  There is no restriction | limiting in particular as reaction temperature which performs the said reaction, Although it can select suitably according to the objective, 20 to 70 degreeC is preferable and 50 to 70 degreeC is more preferable. When the reaction temperature is less than 20 ° C., the reactivity may be poor, and when it exceeds 70 ° C., alteration such as coloring of the solution may occur.

  There is no restriction | limiting in particular as reaction time which performs the said reaction, Although it can select suitably according to the objective, 6 hours-48 hours are preferable, and 18 hours-24 hours are more preferable. If the reaction time is less than 6 hours, the reaction may not proceed sufficiently, and if it exceeds 48 hours, alteration such as coloring of the solution may occur.

(Xylan derivative and method for producing the same)
The xylan derivative of the present invention is a compound in which at least one of the hydroxyl groups in the xylan having a structural unit represented by the following structural formula (1) is substituted with a substituent having an azide group.
Further, the method for producing a xylan derivative of the present invention comprises reacting the xylan derivative precursor of the present invention with a compound that substitutes a halogen group of the halogen-containing group of the xylan derivative precursor with an azide group. It is a manufacturing method.
Hereinafter, the manufacturing method of this xylan derivative is demonstrated with description of a xylan derivative.
However, in the structural formula (1), n represents the degree of polymerization. There is no restriction | limiting in particular as said n, Although it can select suitably according to the objective, 10-500 are preferable and 40-500 are more preferable.

<Xylan derivatives>
The substituent having the azide group in the xylan derivative is not particularly limited and may be appropriately selected depending on the type of the xylan derivative precursor. For example, the linear chain optionally having a substituent And a group having an azide group at the terminal of the alkyl group.
There is no restriction | limiting in particular as carbon number of the said alkyl group, Although it can select suitably according to the objective, 2-20 are preferable and 2-6 are more preferable.

  Specific examples of the substituent having an azido group include a 6-azidohexanoyl group, a 5-azidovaleryl group, an 8-azidooctanoyl group, an 11-azidoundecanoyl group, and a 16-azidohexadecanoyl group. It is done.

The substitution degree of the substituent having the azide group in the hydrogen atom of the hydroxyl group of the xylan is not particularly limited and may be appropriately selected depending on the intended purpose. However, the xylan derivative may be a general purpose such as chloroform or dimethylformamide. It is preferably substituted in a range soluble in an organic solvent, the substitution degree is more preferably 1 to 2 and particularly preferably 2 with respect to the hydrogen atom of the hydroxyl group in the monomer unit of xylan.
In the xylan derivative, a hydrogen atom of a hydroxyl group of at least one structural unit in the polymer of xylan may be substituted with a substituent having an azide group, but a hydrogen atom of a hydroxyl group in two or more structural units. The atom is preferably substituted with a substituent having an azide group.
The method for measuring the degree of substitution is not particularly limited and may be appropriately selected depending on the purpose. Examples thereof include elemental analysis, proton nuclear magnetic resonance, carbon nuclear magnetic resonance, and infrared spectroscopy. Can be mentioned.

There is no restriction | limiting in particular as a number average molecular weight of the said xylan derivative, Although it can select suitably according to the objective, 4,000-200,000 are preferable at polystyrene (PS) conversion, 20,000-200, 000 is more preferable.
The number average molecular weight can be measured by gel permeation chromatography (GPC method), viscosity method, terminal group quantification method, and light scattering method.

The thermal decomposition temperature (TG) of the xylan derivative is preferably as high as possible.
The thermal decomposition temperature can be measured with a thermal analyzer (for example, Thermo Plus TG 8120 (manufactured by Rigaku Corporation)).

  Specific examples of the xylan derivative include di-O- (6-azidohexanoyl) -xylan, di-O- (5-azidovaleryl) xylan, di-O- (8-azidooctanoyl) xylan, di-O. -(11-azidoundecanoyl) xylan, di-O- (16-azidohexadecanoyl) xylan, and the like.

Among these, the xylan derivative is preferably a compound represented by the following structural formula (3) in which a hydrogen atom of a hydroxyl group in xylan is substituted with a 6-azidohexanoyl group.
However, in the structural formula (3), y represents the degree of polymerization, and the substituent represented by R ₃ and R ₄ represents any one of the substituent represented by the following structural formula (B) and a hydrogen atom. . However, in the polymer having the structural unit represented by the structural formula (3), at least one of the R ₃ and the R ₄ of at least one structural unit is a substituent represented by the following structural formula (B). is there.
Among these, R ₃ and R ₄ are all referred to as di-O- (6-azidohexanoyl) -xylan (hereinafter referred to as “XylC6N ₃ ”) which is a substituent represented by the following structural formula (B). Is particularly preferred.
There is no restriction | limiting in particular as said y, Although it can select suitably according to the objective, 10-500 are preferable and 40-500 are more preferable.

The physicochemical properties of the XylC6N ₃ are as follows. Here, the physicochemical properties of XylC6N ₃ having a polymerization degree y of 51.4 are shown as an example, but the xylan derivative of the present invention is not limited to this.

-Physicochemical properties of XylC6N _3-
(1) Property: Solid (2) Molecular weight: Number average molecular weight (Mn) is 21,100, weight average molecular weight (Mw) is 37,000, Mw / Mn is 1.75.
(3) The proton nuclear magnetic resonance spectrum measured under conditions of 500 MHz and 25 ° C. in deuterated chloroform is as shown in FIG. 3, and the chart is as follows.
_{1H-NMR (CDCl 3):} δ1.37 (m, 2H, -C H 2 -CH 2 -CH 2 -N 3), 1.59 (m, 4H, -CO-CH 2 -C H 2 -, _{-C H 2 -CH 2 -N 3)} , 2.25 (s, 2H, -CO-CH 2 -), 3.22 (C5-Ha), 3.28 (t, 2H, J = 6.5 _{, -CH 2 -N 3), 3.76} (m, C4-H), 3.90 (C5-He), 4.43 (C1-H), 4.69 (C2-H), 5.00 (C3-H).
(4) The carbon nuclear magnetic resonance spectrum measured under conditions of 500 MHz and 25 ° C. in deuterated chloroform is as shown in FIG. 4, and the chart is as follows.
_{^{13 C-NMR (CDCl 3)}} : δ24.2 (-CO-CH 2 - C H 2 -), 26.1 (- C H 2 -CH 2 -CH 2 -N 3), 28.5 (- C _{H 2 -CH 2 -N 3),} 33.7 (-CO- C H 2 -), 51.2 (-CH 2 -N 3), 62.5 (C5), 70.7 (C2), 71 .6 (C3), 74.1 (C4), 99.8 (C1), 171.7, 172.1 (CO of C2 and C3, representatively).
In ¹ H-NMR and ¹³ C-NMR, chemical shift (δ) and coupling constant (J) indicate “ppm” and “Hz”.

<Method for producing xylan derivative>
The method for producing the xylan derivative of the present invention includes at least a step of reacting the xylan derivative precursor and a compound that substitutes a halogen group of the halogen-containing group of the xylan derivative precursor with an azide group. In addition, other steps are included.

<< Compound that substitutes halogen group of halogen-containing group of xylan derivative precursor with azide group >>
The compound for substituting the halogen group of the halogen-containing group of the xylan derivative precursor with an azide group is not particularly limited as long as it can form an azide ion in a solution, and may be appropriately selected according to the purpose. Although possible, sodium azide is preferred.
As the compound for substituting the halogen group of the halogen-containing group of the xylan derivative precursor with an azide group, a commercially available product may be used, or a compound synthesized by a known method may be used.

<< Reaction between Xylan Derivative Precursor and Compound Replacing Halogen Group of Halogen-Containing Group of Xylan Derivative Precursor with Azide Group >>
The method for reacting the xylan derivative precursor with the compound that substitutes the halogen group of the halogen-containing group of the xylan derivative precursor with an azide group is not particularly limited and may be appropriately selected depending on the purpose. Here, “reaction” means that the halogen group at the terminal of the halogen-containing group of the xylan derivative precursor is replaced with an azide group.

The xylan derivative precursor is preferably dissolved in a solvent before reacting with a compound that substitutes the halogen group of the halogen-containing group of the xylan derivative precursor with an azide group.
There is no restriction | limiting in particular as said solvent, According to the objective, it can select suitably, For example, aprotic polar organic solvents, such as a dimethylformamide, etc. are mentioned. These may be used alone or in combination of two or more.

  The addition amount of the compound that substitutes the halogen group of the halogen-containing group of the xylan derivative precursor with an azide group is not particularly limited and may be appropriately selected depending on the intended purpose. On the other hand, 2 to 4 equivalents are preferable, and 3 to 4 equivalents are more preferable. When the addition amount is less than 2 equivalents, the halogen group of the halogen-containing group of the xylan derivative precursor may not be substituted with an azide group, or the degree of substitution may be insufficient, and even if it exceeds 4 parts by mass The reaction rate does not increase any more, which is disadvantageous in cost.

  There is no restriction | limiting in particular as reaction temperature which performs the said reaction, Although it can select suitably according to the objective, 25 to 60 degreeC is preferable and 50 to 60 degreeC is more preferable. When the reaction temperature is less than 25 ° C, the reaction may be slow.

  There is no restriction | limiting in particular as reaction time which performs the said reaction, Although it can select suitably according to the objective, 12 hours-48 hours are preferable, and 12 hours-24 hours are more preferable. If the reaction time is less than 12 hours, the reaction may not proceed sufficiently.

  Cellulose has a hydroxyl group at the 6-position, but xylan does not have a hydroxyl group at the 6-position and has hydroxyl groups only at the 2- and 3-positions. Even if esterification is performed without protection, it is advantageous in that a derivative in which the maximum degree of substitution of the hydrogen atom of the hydroxyl group is 2 can be obtained.

(Xylan graft copolymer and production method thereof)
The method for producing a xylan graft copolymer of the present invention is a method for producing a xylan graft copolymer by reacting a compound having an alkyne at the terminal with the xylan derivative of the present invention.
The xylan graft copolymer of the present invention is a xylan graft copolymer obtained by the method for producing the xylan graft copolymer of the present invention and having a xylan derivative as a main chain and a polymer as a side chain.
The method for producing a xylan graft copolymer of the present invention is advantageous in that a xylan graft copolymer can be synthesized easily and efficiently based on a cyclization reaction called click chemistry.
Hereinafter, the xylan graft copolymer will be described together with the description of the production method of the xylan graft copolymer.

<Method for producing xylan graft copolymer>
The method for producing a xylan graft copolymer of the present invention includes at least a step of reacting a compound having an alkyne at a terminal with the xylan derivative of the present invention, and further includes other steps as necessary.

<< Compound having alkyne >>
The compound having an alkyne at the terminal is not particularly limited as long as it has an alkyne at the terminal, and can be appropriately selected according to the purpose. Examples thereof include a polymer having an alkyne at the terminal. These may be used alone or in combination of two or more. Among these, a polymer having a propargyl group is preferable, and a polymer having a propargyl group at a terminal and having biodegradability is more preferable. The polymer is preferably a polyester.
As the compound having an alkyne at the terminal, a commercially available product may be used, or a compound synthesized by a known method may be used.

  The biodegradable polymer is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include polylactic acid (polylactide), polycaprolactone, polyhydroxyalkanoic acid, and polybutylene succinate. . These may be used alone or in combination of two or more.

  Specific examples of the compound having an alkyne at the terminal include polylactic acid having a propargyl group, polyhydroxyalkanoic acid, polyε-caprolactone, polybutylene succinate and the like. These may be used alone or in combination of two or more.

Among these, as a compound which has an alkyne at the said terminal, terminal alkyne poly L-lactide represented by following Structural formula (4) is preferable.
However, in the structural formula (4), z represents the degree of polymerization. There is no restriction | limiting in particular as said z, Although it can select suitably according to the objective, 40-75 are preferable and 75 is more preferable.

  The method for synthesizing the compound having an alkyne at the terminal is not particularly limited and may be appropriately selected depending on the purpose. For example, when the compound having an alkyne at the terminal is the terminal alkynized poly L-lactide, Examples of the synthesis method include a method of reacting propargyl alcohol as an initiator with L-lactide in a solvent such as anhydrous toluene containing tin (II) octylate as a catalyst. By changing the charging ratio of lactide, propargyl alcohol (initiator), and tin (II) octylate (catalyst), terminal alkynized poly L-lactides having various degrees of polymerization can be synthesized.

  The amount of the compound having an alkyne at the terminal is not particularly limited and can be appropriately selected according to the type of the compound having an alkyne at the terminal. 1 equivalent to 2 equivalents are preferable, and 0.1 equivalent to 0.13 equivalent are more preferable. When the addition amount is less than 0.1 equivalent, the introduction rate of the compound having an alkyne at the terminal in the side chain of the xylan derivative may be insufficient.

  There is no restriction | limiting in particular as reaction temperature which performs the said reaction, Although it can select suitably according to the objective, 10 to 30 degreeC is preferable and 15 to 25 degreeC is more preferable. If it exceeds 30 ° C., chloroform volatilizes, the solubility of the xylan derivative or the compound having an alkyne at the terminal is lowered, and the reaction efficiency may deteriorate.

  There is no restriction | limiting in particular as reaction time which performs the said reaction, Although it can select suitably according to the objective, 12 hours-24 hours are preferable, and 20 hours-24 hours are more preferable. Beyond 24 hours, the reaction is complete and further agitation can be costly.

<Xylan graft copolymer>
The xylan graft copolymer of the present invention can be suitably obtained by the method for producing a graft polymer of the present invention, and has the xylan derivative as a main chain and the polymer as a side chain.

<< Main chain >>
The main chain in the xylan graft copolymer is composed of the xylan derivative, and the molecular chain length is not particularly limited and can be appropriately selected according to the purpose.

<< Side Chain >>
The side chain in the xylan graft copolymer is not particularly limited as long as it is a polymer, and can be appropriately selected according to the purpose. However, a biodegradable polymer is preferable, and a polyester is more preferable.
There is no restriction | limiting in particular as the introduction rate of the said side chain, According to the objective, it can select suitably, The polymer should just have even one side chain.
The number of side chains in the xylan graft copolymer can be calculated by the following formula 1 based on the molecular weight in terms of polystyrene (PS).
N = (X−Y) / Z Formula 1
In Formula 1, X represents the number average molecular weight of the xylan graft copolymer, Y represents the number average molecular weight of the main chain, and Z represents the number average molecular weight of the side chain.

There is no restriction | limiting in particular as a number average molecular weight of the said xylan graft copolymer, Although it can select suitably according to the objective, 20,000 or more are preferable and 60,000-300,000 in polystyrene (PS) conversion. More preferred.
The number average molecular weight can be measured by gel permeation chromatography (GPC method), viscosity method, terminal group quantification method, light scattering method and the like.

The type of the xylan graft copolymer can be appropriately selected depending on the type of xylan derivative or polymer to be reacted, and the xylan-graft-poly L-lactide represented by the following structural formula (5) (hereinafter referred to as “XylC6N”). _It may be referred to as “ _3- g-PLLA”).
However, in the structural formula (5), m represents the degree of polymerization, and the substituents represented by R ₅ and R ₆ are represented by the polymer represented by the following structural formula (C) and the following structural formula (B). Represents any of the substituents. However, in the polymer having the structural unit represented by the structural formula (5), at least one of the R ₅ and the R ₆ of at least one structural unit is a polymer represented by the following structural formula (C). .
There is no restriction | limiting in particular as said m, Although it can select suitably according to the objective, 10-500 are preferable and 50-500 are more preferable.
However, in the said structural formula (C), p represents a polymerization degree. There is no restriction | limiting in particular as said p, Although it can select suitably according to the objective, 40-75 are preferable and 75 is more preferable.

The physicochemical properties of the XylC6N ₃ -g-PLLA are as follows. Here, the physicochemical properties of XylC6N ₃ -g-PLLA having a polymerization degree m of 51.4 are shown as an example, but the xylan graft copolymer of the present invention is not limited thereto.

Physico-chemical properties of -XylC6N ₃ -g-PLLA -
(1) Property: Solid (2) Molecular weight: Number average molecular weight (Mn) is 67,600, weight average molecular weight (Mw) is 106000, and Mw / Mn is 1.56.
(3) The proton nuclear magnetic resonance spectrum measured under conditions of 500 MHz and 25 ° C. in deuterated chloroform is as shown in FIG. 5, and the chart is as follows.
_{^{1 H-NMR (CDCl 3)}} : δ1.31 (-C H 2 -CH 2 -CH 2 -N 3), 1.51 (CH 3 (PLLA), - CO-CH 2 -C H 2 -, - _{C H 2 -CH 2 -N 3)} , 2.18 (s, 2H, -CO-CH 2 -), 3.21 (-CH 2 -N 3, C5-H a (overlapped)), 3.65 _{(C4-H), 3.83 (} C5-H e), 4.28 (C * H (end)), 4.37 (C1-H), 4.62 (C2-H), 4.94 ( C3-H), 5.09 (C * H (PLLA))
(4) The carbon nuclear magnetic resonance spectrum measured under conditions of 500 MHz and 25 ° C. in deuterated chloroform is as shown in FIG. 6, and the chart is as follows.
_{^{13 C-NMR (CDCl 3)}} : δ16.6 (CH 3 (PLLA)), 20.5 (CH 3 (PLLA, end)), 24.2 (-CO-CH 2 - C H 2 -), 26 _{.1 (- C H 2 -CH 2} -CH 2 -N 3), 28.5 (- C H 2 -CH 2 -N 3), 33.7 (-CO- C H 2 -), 51.2 _{(-CH 2 -N 3), 62.5} (C5), 66.7 (C * (PLLA, end)), 69.0 (C * (PLLA)), 70.7 (C2), 71.7 (C3), 74.1 (C4), 99.8 (C1), 123.6 (-N- C = C-), 142.1 (-N-C = C- ), 169.6 (CO ( PLLA)), 171.6, 172.1 (CO of C2 and C3, representatively)
In ¹ H-NMR and ¹³ C-NMR, chemical shift (δ) and coupling constant (J) indicate “ppm” and “Hz”.

(Polymer molded product)
The polymer molding of the present invention contains at least one of the xylan derivative of the present invention and the xylan graft copolymer of the present invention, and further contains other components as necessary.

  The content of at least one of the xylan derivative and the xylan graft copolymer in the polymer molded body is not particularly limited and may be appropriately selected depending on the purpose. The polymer molded body may be the xylan derivative itself or the xylan graft copolymer itself.

There is no restriction | limiting in particular as said other component, According to the objective, it can select suitably, For example, a well-known additive etc. are mentioned. Further, other resins may be mixed.
There is no restriction | limiting in particular also as content of the said other component, According to the objective, it can select suitably.

  There is no restriction | limiting in particular as a form of the said polymer molded object, Although it can select suitably according to the objective, It is preferable that it is a film or a fiber.

<Film>
The method for producing the film is not particularly limited and may be appropriately selected according to the purpose. For example, at least one of the xylan derivative and the xylan graft copolymer is dissolved in a desired solvent, and a desired container is obtained. And then drying and molding, at least one of the xylan derivative and the xylan graft copolymer at a temperature equal to or higher than the melting point, and molding, or at least one of the xylan derivative and the xylan graft copolymer. Examples include a method of forming by deforming at a temperature higher than the transition point.
The solvent is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include highly volatile organic solvents such as chloroform and dichloromethane. These may be used alone or in combination of two or more. Among these, the solvent is preferably chloroform.

  There is no restriction | limiting in particular as the usage-amount of the said solvent, if the said xylan derivative can be melt | dissolved, According to the objective, it can select suitably. If the xylan derivative cannot be dissolved, a non-uniform film may be formed.

  The drying method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include freeze drying, hot air drying, spray drying, fluidized bed drying, and air drying. .

  There is no restriction | limiting in particular as thickness of the said film, According to the objective, it can select suitably.

<Application>
Since the polymer molded body contains the xylan derivative, it can be used as an alternative resource for petroleum, and can be suitably used for packaging materials, filters, nonwoven fabrics, etc. as an environmentally friendly material that does not increase carbon dioxide. .

  EXAMPLES The present invention will be specifically described below with reference to examples of the present invention, but the present invention is not limited to these examples.

(Preparation Example 1: Extraction of hardwood xylan)
1 L of 10 mass% sodium hydroxide aqueous solution was added to 50 g of hardwood (eucalyptus kraft pulp, manufactured by Nippon Paper Industries Co., Ltd.), and alkali extraction was performed while stirring at 25 ° C. for 2 hours. Next, this was filtered using a filter paper (No. 1, manufactured by Advantech Toyo Co., Ltd.) and further washed with water. Next, the extract was adjusted to pH 7.0 with acetic acid, 1 L of ethanol (purity 99%, manufactured by Wako Pure Chemical Industries, Ltd.) was added thereto, and the mixture was allowed to stand at 25 ° C. for 12 hours. Next, the mixture was centrifuged at 10,000 rpm for 10 minutes, and xylan was recovered as a precipitate. Ethanol was added again to the precipitate, and the precipitate was washed by centrifugation under the same conditions. This washing was performed twice in total. Distilled water was added again to the precipitate, and the precipitate was washed by centrifugation under the same conditions. This washing was performed three times in total. The washed precipitate was dried overnight by freeze-drying to obtain 2.4 g of powdered hardwood xylan. The yield was 4.8% by mass.

Example 1: Synthesis of di-O- (6-bromohexanoyl) -xylan
As shown in the following scheme, di-O- (6-bromohexanoyl) -xylan (XylC6Br) represented by the structural formula (2) was synthesized.
1.13 g of hardwood xylan (number average molecular weight: about 10,000) prepared in Preparation Example 1 was dispersed in 20 mL of dimethylacetamide (DMAc) and stirred at 120 ° C. for 2 hours. After the temperature of the reaction solution was lowered to 100 ° C., lithium chloride (LiCl) dried overnight at 150 ° C. was added. The temperature was returned to room temperature and stirred until the reaction solution became transparent. After 1.5 hours, 3.7 g of dimethylaminopyridine (DMAP; 4 equivalents to anhydrous xylose unit (AXU)) and 6-bromohexanoyl chloride (4 to AXU) Equivalent) 6.5 mL was added to the reaction and stirred at 70 ° C. for 2 days. After completion of the reaction, the reaction solution was dropped into 800 mL of methanol, and the precipitate was collected by filtration, washed with methanol and water, dried under reduced pressure, and the target compound di-O represented by the following structural formula (2). 3.16 g of-(6-bromohexanoyl) -xylan was obtained. The yield was 76.0% by mass.

In the structural formula (1) and the structural formula (2), n and x each represent a degree of polymerization.

<Measurement of number average molecular weight and weight average molecular weight>
The number average molecular weight (Mn) and weight average molecular weight (Mw) of XylC6Br were measured by gel permeation chromatography (GPC method) under the following measurement conditions. Mn and Mw were converted to polystyrene (PS).
As a result, the degree of polymerization x in XylC6Br was 44.0, the number average molecular weight (Mn) was 21,400, the weight average molecular weight (Mw) was 37,600, and Mw / Mn was 1.76.
[Measurement condition]
Apparatus: Shimadzu 10A (manufactured by Shimadzu Corporation)
Column: Shodex K-806M / K-802 connection column (manufactured by Shodex)
Column temperature: 40 ° C
Moving layer: Chloroform Flow rate: 0.8 mL / min Apply: 50 μL

<Measurement of proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum>
The proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of XylC6Br were measured by JEOL JNM-A500 FT-NMR in deuterated chloroform at 500 MHz and 25 ° C. Tetramethylsilane (TMS) was used as an internal standard substance.
A proton nuclear magnetic resonance spectrum is shown in FIG. 1, and a chart is shown below. The carbon nuclear magnetic resonance spectrum is shown in FIG. 2 and the chart is shown below. As a result, the substitution degree of Br was 2. The chemical shift (δ) and the coupling constant (J) indicate “ppm” and “Hz”.

_{^{1 H-NMR (CDCl 3)}} : δ1.44 (m, 2H, -C H 2 -CH 2 -CH 2 -Br), 1.59 (m, 2H, -CO-CH 2 -C H 2 -) _{, 1.77 (m, 2H, -C} H 2 -CH 2 -Br), 2.26 (s, 2H, -CO-CH 2 -), 3.23 (C5-Ha), 3.54 (t _{, 2H, J = 6.5, -CH} 2 -Br), 3.76 (C4-H), 3.89 (C5-He), 4.43 (C1-H), 4.69 (C2-H ), 5.00 (C3-H).

_{^{13 C-NMR (CDCl 3)}} : δ24.0 (-CO-CH 2 - C H 2 -), 26.3 (- C H 2 -CH 2 -CH 2 -Br), 32.1 (- C H _{2 -CH 2 -Br), 33.7 (} -CO- C H 2 -), 44.8 (-CH 2 -Br), 62.5 (C5), 70.7 (C2), 71.7 ( C3), 74.2 (C4), 99.9 (C1), 171.7, 172.2 (CO of C2 and C3, representatively).

(Example 2: Synthesis of di-O- (6-azidohexanoyl) -xylan)
As shown in the following scheme, di-O- (6-azidohexanoyl) -xylan (XylC6N ₃ ) represented by the structural formula ( ₃ ) was synthesized.
1.69 g of sodium azide (NaN ₃ ; 4 equivalents to AXU) was added to 20 mL of dimethylformamide solution (DMF) containing 3.16 g of XylC6Br synthesized in Example 1, and the mixture was stirred at 60 ° C. for 7 days. The reaction solution is returned to room temperature, extracted with chloroform and water, the chloroform layer is concentrated, and the target compound di-O- (6-azidohexanoyl) -xylan represented by the following structural formula (3) is obtained. 1.44 g was obtained as a solid. The yield was 54.1% by mass.

In the structural formula (2) and the structural formula (3), x and y represent the degree of polymerization, respectively.

As a result of measuring the number average molecular weight and the weight average molecular weight in the same manner as in Example 1, the degree of polymerization y in XylC6N ₃ was 51.4, the number average molecular weight (Mn) was 21,100, and the weight average molecular weight (Mw ) Was 37,000, and Mw / Mn was 1.75.
Moreover, the proton nuclear magnetic resonance spectrum and the carbon nuclear magnetic resonance spectrum were measured by the same method as in Example 1.
A proton nuclear magnetic resonance spectrum is shown in FIG. 3, and a chart is shown below. The carbon nuclear magnetic resonance spectrum is shown in FIG. 4 and the chart is shown below. As a result, the degree of substitution of N ₃ was 2. The chemical shift (δ) and the coupling constant (J) indicate “ppm” and “Hz”.

_{1H-NMR (CDCl 3):} δ1.37 (m, 2H, -C H 2 -CH 2 -CH 2 -N 3), 1.59 (m, 4H, -CO-CH 2 -C H 2 -, _{-C H 2 -CH 2 -N 3)} , 2.25 (s, 2H, -CO-CH 2 -), 3.22 (C5-Ha), 3.28 (t, 2H, J = 6.5 _{, -CH 2 -N 3), 3.76} (m, C4-H), 3.90 (C5-He), 4.43 (C1-H), 4.69 (C2-H), 5.00 (C3-H).

_{13C-NMR (CDCl 3):} δ24.2 (-CO-CH 2 - C H 2 -), 26.1 (- C H 2 -CH 2 -CH 2 -N 3), 28.5 (- C H _{2 -CH 2 -N 3), 33.7} (-CO- C H 2 -), 51.2 (-CH 2 -N 3), 62.5 (C5), 70.7 (C2), 71. 6 (C3), 74.1 (C4), 99.8 (C1), 171.7, 172.1 (CO of C2 and C3, representatively).

  The results of Example 1 and Example 2 are summarized in Table 1 below.

In Table 1, “DPn” represents the number (Mn / R) obtained by dividing the number average molecular weight (Mn) by the mass (R) of the repeating unit.

(Synthesis Example 1: Synthesis of terminal propargylated poly L-lactide)
As shown in the following scheme, terminal alkyneed poly L-lactide (terminal propargylated poly L-lactide) represented by the following structural formula (4) was synthesized by the following method.
To a stirring solution of anhydrous toluene (4 mL) containing 51.8 μL of propargyl alcohol (1 equivalent) and 3 mL of tin (II) octylate (Sn (Oct) ₂ ; 1 equivalent) at 90 ° C. An anhydrous toluene (6 mL) solution of L-lactide (2.0 g, 15 equivalents, manufactured by Musashino Chemical Laboratory Co., Ltd.) was added dropwise to (propargyl alcohol) and stirred for 24 hours. The reaction solution was reprecipitated into 500 mL of methanol, and then centrifuged at 10,000 rpm for 4 minutes to collect the precipitate. Methanol was again added to the precipitate, and the precipitate was washed by centrifugation under the same conditions. This washing was performed twice in total. As a result, 1.43 g of a target terminal propargylated poly L-lactide (hereinafter sometimes referred to as “propargyl-PLLA4”) represented by the following structural formula (4) was obtained. The yield was 71.7% by mass.

In the structural formula (4), z represents the degree of polymerization.

  In the synthesis of propargyl-PLLA4, propargyl-PLLA1 to 3 and propargyl were the same as propargyl-PLLA4 except that the charging ratio of lactide and initiator (propargyl alcohol) was changed to the values shown in Table 2 below. -PLLA5-6 were prepared.

  In the same manner as in Example 1, the number average molecular weight (Mn) and the weight average molecular weight (Mw) were measured. The results are shown in Table 2 below.

In Table 2, “DPn” represents the number (Mn / R) obtained by dividing the number average molecular weight (Mn) by the mass (R) of the repeating unit, and DP represents PLLA for terminal alkyne C—H in NMR analysis. It represents the C * H ratio ([C * H] / [C≡C—H]) of the chain. The molecular chain length was calculated from DPn.

The proton nuclear magnetic resonance spectrum and carbon nuclear magnetic resonance spectrum of propargyl-PLLA4 were measured in the same manner as in Example 1.
A proton nuclear magnetic resonance spectrum is shown in FIG. 7 and a chart is shown below. The carbon nuclear magnetic resonance spectrum is shown in FIG. 8, and the chart is shown below. The chemical shift (δ) and the coupling constant (J) indicate “ppm” and “Hz”.

¹ H-NMR (CDCl ₃ ): δ 1.48, 1.49 (d, 3H, CH ₃ (end)), 1.58, 1.59 (CH ₃ ), 2.51 (t, 1H, C≡ ^{C-H), 4.36 (q} , 1H, C * H (end)), 4.73 (dd, 2H, -C H 2 -C≡CH), 5.17 (C * H).

_{^{13 C-NMR (CDCl 3)}} : δ16.6 (CH 3), 20.5 (CH 3 (end)), 52.9 (- C H 2 -C≡CH), 66.7 (C * (end ^{)), 69.0 (C *)} , 75.6 (-C≡CH), 77.0 (overlapped, -C≡ C H), 169.6 (CO).

In the proton NMR spectrum, the degree of polymerization calculated from the peak area ratio of the proton C≡CH at the alkyne terminal and the C ^* H proton at the PLLA chain almost coincided with the number average degree of polymerization, so that the propargyl group is the starting point at the PLLA terminal. As a result, it was found that a polymer having no alkyne at the terminal is hardly mixed.

Example 3: Synthesis of di-O- (6-azidohexanoyl) -xylan-graft-poly L-lactide
As shown in the following scheme, XylC6N ₃ represented by the following structural formula (3) and propargyl-PLLA represented by the following structural formula (4) were subjected to a cyclization reaction called click chemistry by the following method. Then, di-O- (6-azidohexanoyl) -xylan-graft-poly L-lactide represented by the following structural formula (5) in which the PLLA chain was grafted to the main chain of the xylan derivative was synthesized.
20.0 mg of XylC6N ₃ synthesized in Example 2, 32.3 mg of propargyl-PLLA4 synthesized in Synthesis Example 1 (about 0.125 equivalent to AXU), N, N, N ′, N ″ , N ″ -pentamethyldiethylenetriamine (PMDETA) 10.6 mg (10 equivalents to PLA), and a 2.4 mL solution of chloroform / dimethylformamide (1/1 (v / v)) was frozen and degassed Thereafter, 8.7 mg of Cu (I) Br (2 equivalents to the monomer of PLA) was added, and the mixture was stirred for 24 hours under reduced pressure. After concentration under reduced pressure, the compound in the DMF solution was reprecipitated in 100 ml of ethanol and filtered. the following structural formula the compounds of interest represented by formula (5) di -O- (6- azido-hexanoyl) - xylan - graft - poly L- lactide (hereinafter, "XylC6N ₃ -g-PLLA4" Referred it is.) Was obtained 42.0 mg. The yield was 80.3 mass%.

In the structural formula (3), the structural formula (4), and the structural formula (5), y, z, m, and p each represent the degree of polymerization.

The result of having measured the proton nuclear magnetic resonance spectrum and the carbon nuclear magnetic resonance spectrum by the same method as Example 1. FIG.
The proton nuclear magnetic resonance spectrum is shown in FIG. Further, carbon nuclear magnetic resonance spectra are shown in FIGS. 6A, 6B, and 6C, and charts are shown below. As a result, the degree of substitution of N ₃ was 2. The chemical shift (δ) and the coupling constant (J) indicate “ppm” and “Hz”.
The degree of polymerization m in XylC6N ₃ -g-PLLA calculated from the molecular weight value measured by GPC method in Example 1 and Synthesis Example 1 was 51.4, and the degree of polymerization p was 74.7.

_{^{1 H-NMR (CDCl 3)}} : δ1.31 (-C H 2 -CH 2 -CH 2 -N 3), 1.51 (CH 3 (PLLA), - CO-CH 2 -C H 2 -, - _{C H 2 -CH 2 -N 3)} , 2.18 (s, 2H, -CO-CH 2 -), 3.21 (-CH 2 -N 3, C5-Ha (overlapped)), 3.65 ( C4-H), 3.83 (C5-He), 4.28 (C ^* H (end)), 4.37 (C1-H), 4.62 (C2-H), 4.94 (C3- H), 5.09 (C ^* H (PLLA),).

_{^{13 C-NMR (CDCl 3)}} : δ16.6 (CH 3 (PLLA)), 20.5 (CH 3 (PLLA, end)), 24.2 (-CO-CH 2 - C H 2 -), 26 _{.1 (- C H 2 -CH 2} -CH 2 -N 3), 28.5 (- C H 2 -CH 2 -N 3), 33.7 (-CO- C H 2 -), 51.2 ^{_{(-CH 2 -N 3), 62.5}} (C5), 66.7 (C * (PLLA, end)), 69.0 (C * (PLLA)), 70.7 (C2), 71.7 (C3), 74.1 (C4), 99.8 (C1), 123.6 (-N- C = C-), 142.1 (-N-C = C- ), 169.6 (CO ( PLLA)), 171.6, 172.1 (CO of C2 and C3, representatively).

As a result of NMR, peaks derived from xylan and PLLA chains were observed. In particular, in the carbon nuclear magnetic resonance spectrum, peaks derived from the 1,2,3-triazole ring are observed at 123.6 (-N- C = C-), 142.1 (-N-C = C- ), and click It indicated that a cyclization reaction by chemistry occurred.

Table 3 shows the results of GPC measurement of XylC6N ₃ -g-PLLA4. XylC6N ₃ -g-PLLA4 showed a single elution peak, and the peaks of the raw materials XylC6N ₃ and PLLA were not observed, suggesting that the PLLA chain was quantitatively grafted to the xylan main chain.

From the molecular weight in terms of PS, the number N of propargyl-PLLA4 side chains for one xylan main chain (XylC6N ₃ ) was calculated by the following formula 1 and was 8.8.
N = (X−Y) / Z Formula 1
In Formula 1, X represents the number average molecular weight of XylC6N ₃ -g-PLLA4, Y represents the number average molecular weight of XylC6N ₃ , and Z represents the number average molecular weight of the PLLA chain.

The weight ratio (%) of PLLA chain in one molecule of XylC6N ₃ -g-PLLA4 was calculated by the following formula 2 and was 68.8.
PLLA weight ratio (%) = (XY) / X
In the above formula 2, X represents the number average molecular weight of XylC6N ₃ -g-PLLA4, and Y represents the number average molecular weight of XylC6N ₃ .

(Example 4: Production of film)
20 mg of XylC6N ₃ -g-PLLA synthesized in Example 3 was used, dissolved in 10 mL of chloroform, poured into a petri dish (diameter 5 cm), and dried in a fume hood (25 ° C.) for 24 hours.
The photograph after drying is shown in FIG. Thus, it was found that a film can be produced from the xylan graft copolymer.

  According to the xylan derivative of the present invention and a method for producing the same, a precursor of the xylan derivative and a method for producing the xylan derivative, a method for producing the xylan graft copolymer and a method for producing the polymer, and a polymer molded body, Further, it is possible to provide plastic materials, crystal nucleating agents, crosslinking agents, and the like that can be applied to filters, nonwoven fabrics, and the like.

Claims (11)

A xylan derivative precursor, wherein at least one of hydrogen atoms of a hydroxyl group in xylan having a structural unit represented by the following structural formula (1) is substituted with a halogen-containing group.
However, in the structural formula (1), n represents the degree of polymerization.   The xylan derivative precursor according to claim 1, wherein the substitution degree of the hydroxyl group in the monomer unit of xylan with respect to a hydrogen atom is 2. A method for producing a xylan derivative precursor, which comprises reacting a xylan having a structural unit represented by the following structural formula (1) with a halogen-containing compound to produce a xylan derivative precursor.
However, in the structural formula (1), n represents the degree of polymerization. A xylan derivative, wherein at least one of hydrogen atoms of a hydroxyl group in a xylan having a structural unit represented by the following structural formula (1) is substituted with a substituent having an azide group.
However, in the structural formula (1), n represents the degree of polymerization.   The xylan derivative according to claim 4, wherein the substitution degree of the hydroxyl group in the monomer unit of xylan with respect to a hydrogen atom is 2.   A xylan derivative is produced by reacting the xylan derivative precursor according to claim 1 with a compound that substitutes a halogen group of a halogen-containing group of the xylan derivative precursor with an azide group. A method for producing a xylan derivative.   A method for producing a xylan graft copolymer, comprising reacting a compound having an alkyne at a terminal with the xylan derivative according to any one of claims 4 to 5.   The method for producing a xylan graft copolymer according to claim 7, wherein the compound having an alkyne at the terminal is a polymer having a propargyl group.   A xylan graft copolymer obtained by the method for producing a xylan graft copolymer according to any one of claims 7 to 8, wherein the xylan graft copolymer has a xylan derivative as a main chain and a polymer as a side chain.   A polymer molded article comprising at least one of the xylan derivative according to any one of claims 4 to 5 and the xylan graft copolymer according to claim 9.   The polymer molded body according to claim 10, which is a film.