CN117105788A - Bio-based carboxylic ester structure-containing polyene monomer and preparation and application thereof - Google Patents

Abstract

The invention discloses a biobased carboxylic ester structure-containing polyene monomer, and preparation and application thereof. The biobased carboxylic ester structure-containing polyene monomer disclosed by the invention is prepared from vanillin as a raw material, has a wide source, can be regenerated, is green and environment-friendly, contains a carboxylic ester structure, has the characteristic of degradability when being used for preparing a thermosetting polymer, has multiple groups of terminal double bonds, and has the characteristics of high crosslinking degree, good mechanical property, high glass transition temperature and good light transmittance after being used for preparing the thermosetting polymer through click reaction, as shown in the attached figure 1 of the specification; the preparation method is environment-friendly, simple in synthesis condition and low in preparation cost.

Description

A kind of bio-based polyene monomer containing carboxylic acid ester structure and its preparation and application

Technical field

The invention belongs to the field of chemistry, and in particular relates to a bio-based carboxylic acid ester structure-containing polyene monomer and its preparation and application.

Background technique

Polyester is an important type of polymer material with diverse structures and excellent properties. It is widely used in our production and life. The raw materials for preparing polyester currently mainly come from non-renewable petroleum-based resources and do not meet the requirements for sustainable development. Therefore, it is particularly necessary to replace traditional petroleum-based resources with renewable biomass resources to prepare polyester materials.

Lignocellulose is one of the most abundant biomass resources. It can be converted into various small molecule compounds through chemical catalytic conversion or biological conversion technology, providing a basis for the design and synthesis of new bio-based monomers and polymers. important material source.

As an important bio-based platform compound, 2,5-furandicarboxylic acid (FDCA) has a structure similar to petroleum-based terephthalic acid, and polyethylene furandicarboxylate (PEF) synthesized from ethylene glycol has the same PET has similar properties and is an ideal substitute for PET. Research shows that the performance of PEF has the following advantages compared with PET: its oxygen barrier capability is 11 times that of PET, its carbon dioxide barrier capability is 19 times that of PET, and its tensile modulus is 16 times that of PET (Macromolecules. 2015; 48(7):2184).

However, the current price of FDCA is relatively expensive, which limits its large-scale industrial production. In contrast, vanillin derived from lignin has been industrially produced and has more advantages than FACA in terms of cost. Polyester materials based on vanillin have attracted much attention. . For example, vanillin and levulinic acid are used to obtain hydroxy acid monomers through Aldol condensation reaction, and then through melt polycondensation to obtain vanillin-based polyester with similar properties to PET and a higher glass transition temperature (Chemcatchem. 2018; 10(23) ):5377).

However, the current preparation of most bio-based polyesters is based on the polycondensation reaction of dibasic acids/esters and diols/esters, and ester bonds are formed during the polycondensation process. The polycondensation reaction uses organic metals as catalysts and is carried out at high temperatures and high vacuum. The prepared polyester contains metal impurities and has problems such as discoloration and degradation. The preparation conditions are harsh and the cost is relatively high. Although enzyme-catalyzed polymerization can overcome the shortcomings of metal catalysis, the enzyme is more expensive and has poor thermal stability, which limits its wide application. The development of new green polymerization technologies or the application of polymerization methods have greatly promoted research on controllable synthesis of polymers. Therefore, using biomass or biomass-based monomers as raw materials, using green chemistry methods to design and synthesize new polymerizable monomers, study new polymerization methods, and study the structure and property relationship of new polyesters are the research frontiers in this field.

Contents of the invention

The object of the present invention is to provide a bio-based carboxylic acid ester structure-containing polyene monomer and its preparation and application. The biobased polyene monomer containing carboxylic acid ester structure of the present invention uses vanillin as raw material and combines the etherification reaction of phenolic hydroxyl groups, the Claisen rearrangement reaction and the Tishchenko reaction of aldehyde groups to construct carboxylic acid esters and double bonds. Structural monomers are then click-polymerized with multifunctional thiol monomers to prepare a series of sulfur-containing cross-linked polyesters with adjustable structural properties, which have high cross-linking degree, good mechanical properties, high glass transition temperature and light transmission. It has the characteristics of good stability; in addition, it also has the characteristics of green and environmentally friendly synthesis method, simple synthesis conditions and low preparation cost.

The technical solution of the present invention: a bio-based polyene monomer containing carboxylic acid ester structure, the chemical structural formula of which is as follows:

Wherein, n=1-8, R is one of hydrogen atom, methoxy group or allyl group.

A method for preparing the aforementioned bio-based carboxylic acid ester structure-containing polyene monomer, including the following steps:

(1) Using lignin-based aromatic aldehydes and allyl bromide as raw materials, using an inorganic base as a catalyst in an organic solvent, perform an allyl etherification reaction to prepare allylated aromatic aldehydes;

(2) Take the allylated aromatic aldehyde and perform Claisen rearrangement reaction under the protection of inert gas to obtain the rearrangement product;

(3) Use rearrangement products and halogenated olefins as raw materials, use inorganic bases as catalysts in organic solvents, and perform etherification reactions to prepare aromatic aldehyde diene monomers;

(4) Using aromatic aldehyde diene monomer as raw material, repeat steps (2) and (3) to obtain aromatic aldehyde triene monomer;

(5) Using an organic base or an inorganic base as a catalyst, using the aromatic aldehyde diene monomer prepared in step (3) or the aromatic aldehyde triene monomer prepared in step (4) as raw material, in an organic solvent or without Under solvent conditions, bio-based polyene monomers containing carboxylic acid ester structures were prepared through Tishchenko reaction.

In a further solution, in the aforementioned preparation method of bio-based carboxylic acid ester structure-containing polyene monomers, the lignin-based aromatic aldehyde in step (1) is one of vanillin or p-hydroxybenzaldehyde, and allyl The molar ratio of bromine is 1:1-2; the organic solvent is one of methanol, ethanol, N,N-dimethylformamide, N,N-dimethylacetamide or dimethyl sulfoxide Or any several mixed solvents; the inorganic base catalyst is one or any combination of K ₂ CO ₃ , Cs ₂ CO ₃ , KI or NaI, and the dosage is 0.5-0.5-molar molar amount of lignin-based aromatic aldehyde. 2 times; the temperature of the reaction is 50-150°C, and the reaction time is 1-48h.

In a further scheme, in the aforementioned preparation method of bio-based carboxylate structure-containing polyene monomers, the inert gas in step (2) is one of nitrogen, argon or helium, and the temperature of the reaction is 180 -240℃, reaction time is 1-24h.

In a further aspect, in the aforementioned preparation method of bio-based carboxylic acid ester structure-containing polyene monomers, the structural formula of the halogenated olefin described in step (3) is as follows:

Wherein, n=0-7, One or any mixed solvent of methylformamide, N,N-dimethylacetamide or dimethyl sulfoxide; the inorganic base catalyst is K ₂ CO ₃ , Cs ₂ CO ₃ , KI Or one or any combination of NaI, the dosage is 0.5-2 times the molar amount of the Claisen rearrangement product; the reaction temperature is 50-150°C, and the reaction time is 1-48h.

In a further scheme, in the aforementioned preparation method of bio-based carboxylic acid ester structure-containing polyene monomers, the catalyst in step (5) is sodium hydride, potassium hydride, calcium hydride, potassium tert-butyl alkoxide or 1,8-dihydroxide. One of azobispiro[5.4.0]undec-7-ene, the catalyst dosage is 1-20 mol% of the molar weight of the aromatic aldehyde diene monomer or triene monomer; the organic solvent is One of toluene, tetrahydrofuran, methylene chloride, carbon tetrachloride, n-hexane or dimethyl sulfoxide; the temperature of the Tishchenko reaction is 25-120°C, and the reaction time is 1-48h.

A bio-based carboxylate-containing thermosetting sulfur-containing polyester is prepared by using bio-based carboxylate-containing polyene monomers as raw materials and through thiol-ene click polymerization with thiol monomers of different functionalities.

In a further solution, the aforementioned bio-based carboxylic acid ester structure-containing thermosetting sulfur-containing polyester, the thiol monomers are 1,2-ethanedithiol, 1,3-propanedithiol, and 1,6-hexanedithiol. Dithiol, 1,10-decanedithiol, bis(3-mercaptopropionate)ethylene glycol, trimethylolpropane tris(3-mercaptopropionate) or tetrakis(pentaerythritol 3-mercaptopropionate) one or any combination of them.

In a further solution, the aforementioned bio-based carboxylic acid ester structure-containing thermosetting sulfur-containing polyester is specifically prepared as follows: first, the bio-based carboxylic acid ester structure-containing polyene monomer is melted at 90-120°C, and sulfur is added. Alcohol monomer, then add 0.5-3wt% of photoinitiator 1173 or 2,2-dimethoxy-2-phenylacetophenone, stir evenly and cure under UV lamp for 10-30min, and then cure at 70-140 ℃ thermal curing 0.5-12h.

In a further solution, the aforementioned bio-based carboxylic acid ester structure-containing thermosetting sulfur-containing polyester, the blending ratio of the bio-based carboxylic acid ester structure-containing polyene monomer and the thiol monomer is based on the bio-based carboxylic acid ester structure-containing polyene monomer. The C=C double bond in the olefin monomer and the -SH functional group in the thiol monomer are coordinated in a molar ratio of 1:1.

Beneficial effects of the invention

1. The bio-based polyene monomer containing carboxylic acid ester structure of the present invention is prepared from lignin-based aromatic aldehydes as raw materials, and has the advantages of wide source, renewable, green and environmental protection.

2. The bio-based carboxylic acid ester structure-containing polyene monomer of the present invention contains a carboxylic acid ester structure. When preparing a thermosetting polymer, the polymer has the advantage of being degradable.

3. The bio-based carboxylate structure-containing polyene monomer of the present invention has multiple sets of terminal double bonds. After the thermosetting polymer is prepared through click reaction, it has a high degree of cross-linking, good mechanical properties, high glass transition temperature and It has good light transmittance and has good application prospects in light-transmissive films.

4. The preparation method of the present invention is green and environmentally friendly, has simple synthesis conditions and low preparation cost.

Description of drawings

Figure 1 is the chemical structural formula of the bio-based carboxylic acid ester structure-containing polyene monomer of the present invention;

Figure 2 is a hydrogen spectrum of the monomer obtained in Example 4;

Figure 3 is the carbon spectrum of the monomer obtained in Example 4;

Figure 4 is the DSC of the sample prepared in Example 5;

Figure 5 is a TGA analysis of the sample prepared in Example 5;

Figure 6 is an analysis of the mechanical properties of the samples prepared in Example 5;

Figure 7 shows the degradation of the sample of Example 6.

Detailed ways

The present invention will be further described below with reference to the examples, but they are not used as a basis for limiting the present invention.

Embodiments of the invention

Example 1

Allylation reaction of vanillin monomer, the reaction equation is as follows:

Steps: Add 90g vanillin to a 1L flask, add an appropriate amount of absolute ethanol and dissolve it at 40°C. Add 81.75g of anhydrous potassium carbonate and stir for 15 minutes. Add 80.32g of allyl bromide dropwise from a dropping funnel; raise the temperature to 80°C, condense and reflux, and react for 24 hours. Remove anhydrous potassium carbonate by suction filtration, rotary evaporate, dilute with pure water, extract the organic phase with ethyl acetate, add saturated brine to wash, dry with anhydrous sodium sulfate, suction filtrate, and dry to obtain 105g of light yellow liquid, yield 92.34 %.

¹ HNMR (400MHz, DMSO-d6), δ (ppm): 9.84 (s, 1H, -CHO), 7.65–7.05 (m, 3H, aromatic protons), 6.19–5.95 (m, 1H, -CH＝), 5.38 (m,2H,＝CH ₂ -),4.68(m,2H,-CH ₂ -),3.84(s,3H,-CH ₃ ). ¹³ CNMR(101MHz,DMSO-d6)δ(ppm):191.91, 153.49,149.79,133.55,130.21,126.48,118.76,112.88,110.06,69.49,56.02,39.99.

Example 2

The rearrangement reaction of allylated vanillin, the reaction equation is as follows:

Steps: Weigh 105g of allylvanillin (4-allyloxy-3-methoxybenzaldehyde) from Example 1 into a 500mL two-necked round-bottomed flask, and react at 205°C for 3.5h under a nitrogen atmosphere. After the reaction is completed, pour it into a beaker while it is hot and recrystallize with n-hexane to obtain 81.9g of yellow crystals with a yield of 78.00% and a melting point of 80.6°C.

¹ HNMR(400MHz,DMSO-d6)δ(ppm):9.86(s,1H,-OH),9.76(s,1H,-CHO),7.32(s,2H,aromaticprotons),5.94(s,1H,- CH＝),5.05(s,2H,=CH ₂ -),3.88(s,3H,-OCH ₃ ),3.35(m,2H,-CH ₂ -). ¹³ CNMR(100MHz,DMSO-d6)δ( ppm):192.06,151.17,148.61,137.15,128.88,127.58,126.97,116.91,109.82,56.86,40.45,34.30.

Example 3

The etherification reaction equation of the rearranged product is as follows:

Steps: Weigh the 3-allyl-4-hydroxy-5-methoxybenzaldehyde (81.9g) of Example 2 into a 1000mL two-neck bottle, add 300mL of absolute ethanol, and move it to an oil bath at 80°C to dissolve. Then add anhydrous potassium carbonate (65.00g). Propylene bromide (56.77g) was added dropwise with a dropper, then the temperature was raised to 80°C, and the reaction was stopped after refluxing for 24 hours. Filter to remove the salt, add a small amount of water and ethyl acetate to extract, then wash with saturated brine, collect the organic phase, rotary evaporate to remove excess propylene bromide, ethyl acetate, and ethanol, and purify through column to obtain 95g of light yellow liquid product, product The rate is 95.98%.

¹ HNMR (400MHz, CDCl ₃ ) δ (ppm): 9.87 (s, 1H, -CHO), 7.33 (s, 2H, aromatic rotons), 6.19–5.83 (m, 2H, -CH＝), 5.49–4.99 ( m,4H,＝CH ₂ -),4.60(m,2H,-CH ₂ -),3.92(s,3H,-OCH ₃ ),3.48(s,2H,-CH ₂ -). ¹³ CNMR(101MHz, CDCl ₃ )δ(ppm):191.41,153.26,151.30,136.34,134.55,133.89,132.29,126.55,117.96,116.47,108.92,77.29,73.89,55.88,34.24.

Example 4

Steps: Weigh 3-allyl-4-allyloxy-5-methoxybenzaldehyde and sodium hydride from Example 3, add them to the Schlenk bottle, raise the temperature to 110°C, and react for 48 hours. After the reaction is completed, add a small amount of ethyl acetate while it is hot to dissolve and dilute, extract with water and ethyl acetate, combine the organic phases, add silica gel powder and spin to dryness, and separate through column to obtain a light yellow oily substance, that is, bio-based tetraene containing carboxylic acid ester structure Monomer, yield 76%.

¹ HNMR (400MHz, CDCl ₃ ), δ (ppm): 7.55 (s, 1H), 7.49 (s, 1H), 6.87 (s, 2H), 6.18–5.87 (m, 4H), 5.43–5.32 (m, 2H),5.26(s,2H),5.22(dt,J＝10.1,1.3Hz,2H),5.13–4.99(m,4H),4.55(dt,J＝5.9,1.4Hz,2H),4.52–4.46 (m, 2H), 3.87 (d, J = 12.4Hz, 6H), 3.43 (d, J = 6.6Hz, 4H). ¹³ CNMR (101MHz, CDCl ₃ ), δ (ppm): 153.14, 146.25, 137.35, 134.86,134.65,134.53–134.50,132.29,125.98,124.64,122.45,118.08,116.47,112.13,111.00,74.32,67.19,56.37,34.82.

The Tishchenko reaction was performed under different conditions, and the results are shown in Table 1

Table 1 Jishchenko’s reaction under different conditions

Example 5

Steps: Completely melt the vanillin group-containing carboxylate structure polyene monomer (6 mmol) of Example 4 at 100°C, add a certain amount of multifunctional thiol monomer and 1wt% of 2,2-dimethoxy. Stir the base-2-phenyl acetophenone evenly, pour the mixture into a glass petri dish, and then cross-link it under a UV lamp with a wavelength of 365 nm for 10 minutes, and then thermally cure it in an oven at 120°C for 30 minutes to obtain a light yellow transparent film.

Table 2 Thermal properties of the thermosetting material prepared in Example 5

Table 3 Mechanical properties of thermosetting materials obtained in Example 5

Example 6

The films TVE-2SH, TVE-3SH, and TVE-4SH prepared in Example 5 were respectively immersed in a sodium hydroxide aqueous solution (1M) and heated to 60°C to perform a degradation experiment.

Table 4 Degradation time of TVE-SH in 1M NaOH at different temperatures

Example 7

Allylation reaction of p-hydroxybenzaldehyde monomer:

Steps: Add 90g of p-hydroxybenzaldehyde to a 1L flask, add an appropriate amount of absolute ethanol and dissolve it at 40°C. Add 81.75g of anhydrous potassium carbonate and stir for 15 minutes. Add 80.32g of allyl bromide dropwise from a dropping funnel; raise the temperature to 80°C, condense and reflux, and react for 24 hours. Remove anhydrous potassium carbonate by suction filtration, rotary evaporate, dilute with pure water, extract the organic phase with ethyl acetate, add saturated brine to wash, dry with anhydrous sodium sulfate, suction filtrate, and dry to obtain allyl p-hydroxybenzaldehyde .

Rearrangement reaction of allylated p-hydroxybenzaldehyde:

Steps: Weigh the allylated p-hydroxybenzaldehyde of Example 7 into a 500 mL two-necked round-bottomed flask, and react at 205°C for 3.5 hours under a nitrogen atmosphere. After the reaction is completed, pour it into a beaker while it is hot, and recrystallize it with n-hexane to obtain the rearranged product.

Rearrangement product etherification reaction:

Steps: Weigh the aforementioned rearranged product into a 1000 mL two-neck bottle, add 300 mL of absolute ethanol, move it to an oil bath at 80°C to dissolve, and then add anhydrous potassium carbonate (65.00 g). Propylene bromide (56.77g) was added dropwise with a dropper, then the temperature was raised to 80°C, and the reaction was stopped after refluxing for 24 hours. Filter to remove the salt, add a small amount of water and ethyl acetate to extract, then wash with saturated brine, collect the organic phase, rotary evaporate to remove excess propylene bromide, ethyl acetate, ethanol, and purify through column to obtain aromatic aldehyde diene monomer .

Secondary rearrangement-etherification reaction:

Steps: Put the aforementioned etherified p-hydroxybenzaldehyde diene monomer into a 500 mL two-necked round-bottomed flask, and react at 205°C for 3.5 hours under a nitrogen atmosphere. After the reaction is completed, pour it into a beaker while it is hot and recrystallize with n-hexane to obtain the secondary rearrangement product. Take the secondary rearrangement product into a 1000 mL two-necked bottle, add 300 mL of absolute ethanol, move it to an oil bath at 80°C to dissolve, and then add anhydrous potassium carbonate (65.00 g). Propylene bromide (56.77g) was added dropwise with a dropper, then the temperature was raised to 80°C, and the reaction was stopped after refluxing for 24 hours. Filter to remove the salt, add a small amount of water and ethyl acetate to extract, then wash with saturated brine, collect the organic phase, rotary evaporate to remove excess propylene bromide, ethyl acetate, ethanol, and purify through column to obtain p-hydroxybenzaldehyde triene monomer.

Tishchenko's reaction:

Steps: Weigh p-hydroxybenzaldehyde-based triene monomer and sodium hydride, add them to the Schlenk bottle, raise the temperature to 110°C, and react for 48 hours. After the reaction is completed, add a small amount of ethyl acetate while it is hot to dissolve and dilute, extract with water and ethyl acetate, combine the organic phases, add silica gel powder and spin to dryness, and separate through column to obtain a light yellow oily substance, that is, bio-based hexene containing carboxylic acid ester structure monomer.

Example 8

Allylation reaction of vanillin monomer:

Steps: Add vanillin to a 1L flask, add an appropriate amount of methanol and dissolve it at 40°C. Add anhydrous Cs ₂ CO ₃ and stir for 15 minutes. The molar amount of Cs ₂ CO ₃ is 0.5 times the molar amount of vanillin. Use a dropping funnel to add allyl bromide dropwise. The molar ratio of vanillin to allyl bromide is 1:1; raise the temperature to 50°C, condense and reflux, and react for 48 hours. Remove anhydrous potassium carbonate by suction filtration, rotary evaporate, dilute with pure water, extract the organic phase with ethyl acetate, add saturated brine to wash, dry with anhydrous sodium sulfate, suction filtrate, and dry to obtain allyl vanillin.

Rearrangement reaction of allylated vanillin:

Steps: Weigh the aforementioned allylated vanillin into a 500 mL two-necked round-bottomed flask, and react at 180°C for 24 hours under an argon atmosphere. After the reaction is completed, pour it into a beaker while it is hot, and recrystallize it with n-hexane to obtain the rearranged product.

Rearrangement product etherification reaction:

Steps: Weigh the aforementioned rearrangement product into a 1000mL two-necked bottle, add 300mL methanol, move it to an oil bath at 80°C to dissolve, then add Cs ₂ CO ₃ , the molar amount of Cs ₂ CO ₃ is 0.5 times the molar amount of the rearranged product. , add 6-bromo-1-hexene dropwise with a dropper, the molar ratio of the rearranged product to 6-bromo-1-hexene is 1:1, then heat up to 50°C, and stop the reaction after refluxing for 48 hours. Filter to remove the salt, add a small amount of water and ethyl acetate to extract, then wash with saturated brine, collect the organic phase, rotary evaporate to remove excess 6-bromo-1-hexene, ethyl acetate, and methanol, and purify through column to obtain aromatic Aldehyde diene monomer.

Tishchenko's reaction:

Steps: Weigh the aromatic aldehyde diene monomer and potassium hydride into the Schlenk bottle, react at 25°C for 48 hours. After the reaction is completed, add a small amount of ethyl acetate while it is hot to dissolve and dilute, extract with water and ethyl acetate, combine the organic phases, add silica gel powder and spin to dryness, and separate through column to obtain a light yellow oily substance, that is, bio-based tetraene containing carboxylic acid ester structure monomer.

Example 9

Allylation reaction of vanillin monomer:

Steps: Add vanillin to a 1L flask, add an appropriate amount of dimethyl sulfoxide and dissolve it at 40°C. Add anhydrous KI and stir for 15 minutes. The molar amount of KI is twice the molar amount of vanillin. Use a dropping funnel to add allyl bromide dropwise. The molar ratio of vanillin to allyl bromide is 1:2; heat to 150℃, condensation and reflux, react for 1 hour. Remove anhydrous potassium carbonate by suction filtration, rotary evaporate, dilute with pure water, extract the organic phase with ethyl acetate, add saturated brine to wash, dry with anhydrous sodium sulfate, suction filtrate, and dry to obtain allyl vanillin.

Rearrangement reaction of allylated vanillin:

Steps: Weigh the aforementioned allylated vanillin into a 500 mL two-necked round-bottomed flask, and react at 240°C for 1 hour under a helium atmosphere. After the reaction is completed, pour it into a beaker while it is hot, and recrystallize it with n-hexane to obtain the rearranged product.

Rearrangement product etherification reaction:

Steps: Weigh the aforementioned rearranged product into a 1000mL two-necked bottle, add 300mL of dimethyl sulfoxide, move it to an oil bath at 80°C to dissolve, then add NaI, the molar amount of NaI is twice the molar amount of the rearranged product, use Add 10-bromo-1-decene dropwise through a dropper. The molar ratio of the rearranged product to 10-bromo-1-decene is 1:2. Then the temperature is raised to 150°C, and the reaction is stopped after refluxing for 1 hour. Filter to remove the salt, add a small amount of water and ethyl acetate to extract, then wash with saturated brine, collect the organic phase, rotary evaporate to remove excess 10-bromo-1-decene and ethyl acetate, and purify through column to obtain aromatic aldehyde group Diene monomer.

Tishchenko's reaction:

Steps: Weigh the aromatic aldehyde diene monomer and potassium hydride into the Schlenk bottle, and react at 120°C for 1 hour. After the reaction is completed, add a small amount of ethyl acetate while it is hot to dissolve and dilute, extract with water and ethyl acetate, combine the organic phases, add silica gel powder and spin to dryness, and separate through column to obtain a light yellow oily substance, that is, bio-based tetraene containing carboxylic acid ester structure monomer.

Example 10

Allylation reaction of p-hydroxybenzaldehyde monomer:

Steps: Add p-hydroxybenzaldehyde to a 1L flask, add an appropriate amount of methanol and dissolve it at 40°C. Add anhydrous Cs ₂ CO ₃ and stir for 15 minutes. The molar amount of Cs ₂ CO ₃ is 0.5 times the molar amount of p-hydroxybenzaldehyde. Use a dropping funnel to dropwise add allyl bromide, p-hydroxybenzaldehyde and allyl bromide. The molar ratio is 1:1; raise the temperature to 50°C, condense and reflux, and react for 48 hours. Remove anhydrous potassium carbonate by suction filtration, rotary evaporate, dilute with pure water, extract the organic phase with ethyl acetate, add saturated brine to wash, dry with anhydrous sodium sulfate, suction filtrate, and dry to obtain allyl p-hydroxybenzaldehyde .

Rearrangement reaction of allylated p-hydroxybenzaldehyde:

Steps: Weigh the aforementioned allylated p-hydroxybenzaldehyde into a 500 mL two-necked round-bottomed flask, and react at 180°C for 24 hours under an argon atmosphere. After the reaction is completed, pour it into a beaker while it is hot, and recrystallize it with n-hexane to obtain the rearranged product.

Rearrangement product etherification reaction:

Steps: Weigh the aforementioned rearrangement product into a 1000mL two-necked bottle, add 300mL methanol, move it to an oil bath at 80°C to dissolve, then add Cs ₂ CO ₃ , the molar amount of Cs ₂ CO ₃ is 0.5 times the molar amount of the rearranged product. , add propylene bromide dropwise with a dropper, the molar ratio of the rearranged product to propylene bromide is 1:1, then raise the temperature to 50°C, and stop the reaction after refluxing for 48 hours. Filter to remove the salt, add a small amount of water and ethyl acetate to extract, then wash with saturated brine, collect the organic phase, rotary evaporate to remove excess propylene bromide, ethyl acetate, and methanol, and purify through column to obtain p-hydroxybenzaldehyde diene. monomer.

Secondary rearrangement-etherification reaction:

Steps: Put the aforementioned etherified p-hydroxybenzaldehyde diene monomer into a 500 mL two-neck round bottom flask, and react at 180°C for 24 hours under a nitrogen atmosphere. After the reaction is completed, pour it into a beaker while it is hot and recrystallize with n-hexane to obtain the secondary rearrangement product. Take the secondary rearrangement product into a 1000 mL two-necked bottle, add 300 mL of methanol, move it to an oil bath at 80°C to dissolve, then add Cs ₂ CO ₃ , the molar amount of Cs ₂ CO ₃ is 0.5 times the molar amount of the rearranged product, and use a dropper to Add 6-bromo-1-hexene dropwise into the tube. The molar ratio of the secondary rearrangement product to 6-bromo-1-hexene is 1:1. Then the temperature is raised to 50°C and the reaction is stopped after refluxing for 48 hours. Filter to remove the salt, add a small amount of water and ethyl acetate to extract, then wash with saturated brine, collect the organic phase, rotary evaporate to remove excess 6-bromo-1-hexene, ethyl acetate, and methanol, and purify through a column to obtain the right Hydroxybenzaldehyde-based triene monomer.

Tishchenko's reaction:

Steps: Weigh p-hydroxybenzaldehyde-based triene monomer and potassium hydride, add them to the Schlenk bottle, and react at 25°C for 48 hours. After the reaction is completed, add a small amount of ethyl acetate while it is hot to dissolve and dilute, extract with water and ethyl acetate, combine the organic phases, add silica gel powder and spin to dryness, and separate through column to obtain a light yellow oily substance, that is, bio-based hexene containing carboxylic acid ester structure monomer.

Example 11

Allylation reaction of p-hydroxybenzaldehyde monomer:

Steps: Add p-hydroxybenzaldehyde to a 1L flask, add an appropriate amount of dimethyl sulfoxide and dissolve it at 40°C. Add anhydrous KI and stir for 15 minutes. The molar amount of KI is twice the molar amount of p-hydroxybenzaldehyde. Use a dropping funnel to add allyl bromide dropwise. The molar ratio of p-hydroxybenzaldehyde to allyl bromide is 1: 2; Raise the temperature to 150°C, condense and reflux, and react for 1 hour. Remove anhydrous potassium carbonate by suction filtration, rotary evaporate, dilute with pure water, extract the organic phase with ethyl acetate, add saturated brine to wash, dry with anhydrous sodium sulfate, suction filtrate, and dry to obtain allyl p-hydroxybenzaldehyde .

Rearrangement reaction of allylated p-hydroxybenzaldehyde:

Steps: Weigh the aforementioned allylated p-hydroxybenzaldehyde into a 500 mL two-necked round-bottomed flask, and react at 240°C for 1 hour under a helium atmosphere. After the reaction is completed, pour it into a beaker while it is hot, and recrystallize it with n-hexane to obtain the rearranged product.

Rearrangement product etherification reaction:

Steps: Weigh the aforementioned rearranged product into a 1000mL two-necked bottle, add 300mL of dimethyl sulfoxide, move it to an oil bath at 80°C to dissolve, then add NaI, the molar amount of NaI is twice the molar amount of the rearranged product, use Add propylene bromide drop by drop using a dropper. The molar ratio of the rearranged product to propylene bromide is 1:2. Then the temperature is raised to 150°C and the reaction is stopped after refluxing for 1 hour. Filter to remove the salt, add a small amount of water and ethyl acetate to extract, then wash with saturated brine, collect the organic phase, rotary evaporate to remove excess propylene bromide and ethyl acetate, and purify through column to obtain p-hydroxybenzaldehyde diene monomer .

Secondary rearrangement-etherification reaction:

Steps: Put the aforementioned etherified p-hydroxybenzaldehyde diene monomer into a 500 mL two-neck round bottom flask, and react at 240°C for 1 hour under a helium atmosphere. After the reaction is completed, pour it into a beaker while it is hot and recrystallize with n-hexane to obtain the secondary rearrangement product. Take the secondary rearrangement product into a 1000mL two-necked bottle, add 300mL dimethyl sulfoxide, move it to an oil bath at 80°C to dissolve, then add NaI, the molar amount of NaI is twice the molar amount of the rearranged product, use a dropper to gradually 10-bromo-1-decene was added dropwise. The molar ratio of the secondary rearrangement product to 10-bromo-1-decene was 1:2. Then the temperature was raised to 150°C, and the reaction was stopped after refluxing for 1 hour. Filter to remove the salt, add a small amount of water and ethyl acetate to extract, then wash with saturated brine, collect the organic phase, rotary evaporate to remove excess 10-bromo-1-decene and ethyl acetate, and purify through column to obtain aromatic aldehyde group Triene monomer.

Tishchenko's reaction:

Steps: Weigh the aromatic aldehyde triene monomer and potassium hydride, add them to the Schlenk bottle, and react at 120°C for 1 hour. After the reaction is completed, add a small amount of ethyl acetate while it is hot to dissolve and dilute, extract with water and ethyl acetate, combine the organic phases, add silica gel powder and spin to dryness, and separate through column to obtain a light yellow oily substance, that is, bio-based hexene containing carboxylic acid ester structure monomer.

The above descriptions are only preferred embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any person familiar with the technical field can, within the technical scope disclosed by the present invention, use Any equivalent replacement or modification of the created technical solution and its inventive concept shall be covered by the protection scope of the invention.

Claims (10)

1. A bio-based carboxylic ester structure-containing polyene monomer is characterized by having a chemical structural formula as shown in the specification:

wherein n=1 to 8,R is one of a hydrogen atom, a methoxy group or an allyl group.

2. A process for the preparation of a biobased carboxylic acid ester structure containing polyene monomer of claim 1, comprising the steps of:

(1) Using lignin-based aromatic aldehyde and allyl bromide as raw materials, and performing allyl etherification reaction in an organic solvent by using inorganic base as a catalyst to prepare allylated aromatic aldehyde;

(2) Taking allylated aromatic aldehyde, and carrying out claisen rearrangement reaction under the protection of inert gas to obtain a rearrangement product;

(3) The method comprises the steps of (1) taking a rearrangement product and halogenated olefin as raw materials, and carrying out etherification reaction in an organic solvent by taking inorganic base as a catalyst to prepare an aromatic aldehyde diene monomer;

(4) Repeating the steps (2) and (3) by taking an aromatic aldehyde diene monomer as a raw material to obtain an aromatic aldehyde triene monomer;

(5) Organic base or inorganic base is used as a catalyst, the aromatic aldehyde diene monomer prepared in the step (3) or the aromatic aldehyde triene monomer prepared in the step (4) is used as a raw material, and the biological base polyene monomer containing carboxylic ester structure is prepared through quaternary first-class reaction under the condition of organic solvent or no solvent.

3. The method for producing a biobased carboxylic acid ester structure-containing polyene monomer of claim 2, wherein: the lignin-based aromatic aldehyde in the step (1) is one of vanillin or p-hydroxybenzaldehyde, and the molar ratio of the lignin-based aromatic aldehyde to allyl bromide is 1:1-2; the organic solvent is one or a mixture of several of methanol, ethanol, N-dimethylformamide, N-dimethylacetamide or dimethyl sulfoxide; the inorganic base catalyst is K ₂ CO ₃ 、Cs ₂ CO ₃ One or more of KI and NaI are mixed, and the dosage is 0.5-2 times of the molar quantity of lignin-based aromatic aldehyde; the reaction temperature is 50-150 ℃ and the reaction time is 1-48h.

4. The method for producing a biobased carboxylic acid ester structure-containing polyene monomer of claim 2, wherein: the inert gas in the step (2) is one of nitrogen, argon or helium, the reaction temperature is 180-240 ℃, and the reaction time is 1-24h.

5. The method for preparing a biobased carboxylic acid ester structure-containing polyene monomer of claim 2, wherein the halogenated olefin of step (3) has the structural formula:

wherein n=0 to 7, and x is a bromine atom or a chlorine atom; the molar ratio of the rearrangement product to the halogenated olefin is 1:1-2; the organic solvent is one or a mixture of several of methanol, ethanol, N-dimethylformamide, N-dimethylacetamide or dimethyl sulfoxide; the inorganic base catalyst is K ₂ CO ₃ 、Cs ₂ CO ₃ One or more of KI and NaI are mixed, and the dosage is 0.5-2 times of the molar weight of the discharged product; the reaction temperature is 50-150 ℃ and the reaction time is 1-48h.

6. The method for producing a biobased carboxylic acid ester structure-containing polyene monomer of claim 2, wherein: the catalyst in the step (5) is one of sodium hydride, potassium hydride, calcium hydride, potassium tert-butyl alcohol or 1, 8-diazabicyclo [5.4.0] undec-7-ene, and the dosage of the catalyst is 1-20mol% of the molar amount of aromatic aldehyde diene monomer or triene monomer; the organic solvent is one of toluene, tetrahydrofuran, dichloromethane, carbon tetrachloride, n-hexane or dimethyl sulfoxide; the temperature of the quaternary ancestral reaction is 25-120 ℃, and the reaction time is 1-48h.

7. A bio-based carboxylate structure-containing thermosetting sulfur-containing polyester, characterized in that: the bio-based carboxylic ester structure-containing polyene monomer of claim 1 is used as a raw material and is prepared by carrying out mercapto-ene click polymerization with thiol monomers with different functionalities.

8. The biobased carboxylate-structure-containing thermosetting sulfur-containing polyester according to claim 7, wherein: the mercaptan monomer is one or a combination of more than one of 1, 2-ethanedithiol, 1, 3-propanedithiol, 1, 6-hexanedithiol, 1, 10-decanedithiol, ethylene bis (3-mercaptopropionic acid), trimethylol propane tri (3-mercaptopropionic acid) ester or tetra (3-mercaptopropionic acid) pentaerythritol ester.

9. The bio-based carboxylate-structure-containing thermosetting sulfur-containing polyester according to claim 7, wherein the specific preparation method comprises the following steps: melting the biobased carboxylic ester structure-containing polyene monomer at 90-120 ℃, adding a mercaptan monomer, adding 0.5-3wt% of a photoinitiator 1173 or 2, 2-dimethoxy-2-phenylacetophenone, uniformly stirring, curing for 10-30min under an ultraviolet lamp, and then performing thermal curing at 70-140 ℃ for 0.5-12h.

10. The biobased carboxylate-structure-containing thermosetting polymer according to claim 9, wherein: the mixing ratio of the biobased carboxylic acid ester structure-containing polyene monomer to the thiol monomer is matched according to the molar ratio of C=C double bond in the biobased carboxylic acid ester structure-containing polyene monomer to-SH functional group in the thiol monomer of 1:1.