TWI636078B - Biomass thermoplastic polyurethane - Google Patents

Abstract

The present disclosure provides a biomass thermoplastic polyurethane. The biothermoplastic polyurethane is formed by a reaction of a composition comprising: 1-50 parts by weight of modified lignin, wherein the modified lignin has a hydroxyl value (OH value) of less than 3 mmol/g; 50 to 99 parts by weight of the first polyol, wherein the total weight of the modified lignin and the first polyol is 100 parts by weight; and, 40 to 60 parts by weight of the diisocyanate.

Description

Biomass thermoplastic polyurethane

The present disclosure relates to a biomass thermoplastic polyurethane.

Thermoplastic polyurethane (TPU) has been widely used in foam cushions, insulation boards, electronic potting compounds, high performance adhesives, surface coatings, packaging, surface sealants and synthetic fibers due to its flexibility and high elasticity.

Polyols used in the production of thermoplastic polyurethanes are typically derived from petroleum products. However, due to environmental concerns, more and more industrial manufacturing methods are now attempting to replace petroleum products with biomass products. Among them, lignin, as a polyol biomass, can be easily extracted from food-grade and non-food-grade biomass, such as agricultural waste or biomass in forests. However, direct reaction of lignin with isocyanate to form a thermoplastic polyurethane results in loss of thermoplasticity due to excessive crosslinking.

Therefore, the industry needs a novel thermoplastic polyurethane to solve the problems encountered in the prior art.

According to an embodiment of the present disclosure, the present disclosure provides a biomass thermoplastic polyurethane. The biothermoplastic polyurethane can be formed by a reaction of a group of components, the group The composition comprises: 1 to 50 parts by weight of modified lignin; 50 to 99 parts by weight of the first polyol; and, 40 to 60 parts by weight of diisocyanate. Wherein, the modified lignin has a hydroxyl value (OH value) of less than 3 mmol/g, and the total weight of the modified lignin and the first polyol is 100 parts by weight.

The disclosed embodiments provide a biomass thermoplastic polyurethane. The present disclosure utilizes a specific proportion of modified lignin (hydroxy value (OH value) less than 3 mmol / g), polyol, and diisocyanate to prepare a biothermoplastic polyurethane, which can make the obtained biothermoplastic polyurethane have higher Mechanical strength and wear resistance. Further, when unmodified lignin is added to react with a polyol and a diisocyanate, if the amount of lignin added is too large, lignin aggregation is liable to cause a decrease in mechanical strength of the obtained product. If the amount of lignin added is insufficient, the mechanical strength and wear resistance of the obtained product cannot be remarkably improved. Since the present invention uses a modified lignin having a hydroxyl value (OH value) of less than 3 mmol/g to react with a polyhydric alcohol and a diisocyanate, when the amount of lignin is increased, no excessive crosslinking is caused, and thus the resulting bio-based polyurethane has a significant improvement. At the same time of mechanical strength and wear resistance, it also retains thermoplasticity.

According to an embodiment of the present disclosure, the present disclosure provides a biomass thermoplastic polyurethane. The biothermoplastic polyurethane may be formed by a reaction of a composition comprising: 1 to 50 parts by weight (for example, 2 to 25 parts by weight, 10 to 30 parts by weight, or 10 to 20 parts by weight) of modified lignin. 50-99 parts by weight (for example, 75-98 parts by weight, 70-90 Parts by weight, or 80 to 90 parts by weight, of the first polyol; and, 40 to 60 parts by weight (for example, 45 to 55 parts by weight) of the diisocyanate. Wherein, the modified lignin has a hydroxyl value (OH value) of less than about 3 mmol/g, and the total weight of the modified lignin and the first polyol may be 100 parts by weight.

According to an embodiment of the present disclosure, the modified lignin may have at least one terminal functional group of lignin, and the capping functional group is bonded to a residue obtained by dehydrogenating a hydroxyl group on the lignin. Wherein the capping functional group (R ¹ ) is a C _1-4 alkyl group, a phenyl group, ,or Wherein R ² and R ³ are each independently C _1-4 alkyl; and n is 1, 2, 3 or 4.

According to an embodiment of the present disclosure, the C _1-4 alkyl group may be a linear or branched chain alkyl group. For example, a C _1-4 alkyl group can be methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl ( T-butyl), sec-butyl, or isobutyl.

According to an embodiment of the present disclosure, the modified lignin of the present disclosure may have the structure of the formula (I)

Wherein, L is a lignin residue left by removing i hydroxyl groups; R ¹ is a C _1-4 alkyl group, a phenyl group, ,or Wherein R ² and R ² are each independently C _1-4 alkyl; and, n is 1, 2, 3 or 4: and 3 < i ≦ 10 (for example: 3 < i ≦ 9, 3 < i ≦ 7, 3 < i ≦ 6, 3 < i ≦ 5, 3 < i ≦ 4.8, 3 < i ≦ 4.6, 3 < i ≦ 4.4, 3 < i ≦ 4.2, or 3 < i ≦ 4.0).

According to embodiments of the present disclosure, the lignin used to form the modified lignin may be a sulfonate lignin, an alkali lignin, or a combination thereof. According to an embodiment of the present disclosure, the modified lignin may have a hydroxyl value (OH value) of from about 2 mmol/g to 2.9 mmol/g, for example, from 2.1 mmol/g to 2.8 mmol/g, from 2.2 mmol/g to 2.7 mmol/ g, or 2.3 mmol/g to 2.6 mmol/g. If the hydroxyl value (OH value) of the modified lignin is too high, the PU cross-linking tends to lose the thermoplastic property; if the hydroxyl value (OH value) of the modified lignin is too low, the molecular weight is low and the physical properties are poor.

According to an embodiment of the present disclosure, the first polyol is a polymer polyol. According to an embodiment of the present disclosure, the number average molecular weight of the first polyol may be from 500 to 100,000, such as from 500 to 80,000, from 1,000 to 60,000, from 2,000 to 50,000, or from 5,000 to 40,000.

According to an embodiment of the present disclosure, the first polyol may be a polyester polyol, or a polyether polyol. According to an embodiment of the present disclosure, the polyester polyol may be poly(ethylene adipate) diol or poly(1,4-butanediol adipate) diol. (poly(1,4-butylene adipate) diol), poly(ethylene dodecanoate) diol, or poly(1,6-hexanediol adipate) Poly(1,6-hexathylene adipate) diol.

In addition, according to the embodiments of the present disclosure, the polyether polyol may be polyethylene glycol (PEG), polypropylene glycol (PPG), or polytetramethylene ether (polytetramethylene ether). Glycol, PTMEG).

According to an embodiment of the present disclosure, the composition of the present disclosure further comprises a second polyol. Wherein the second polyol is different from the first polyol.

According to an embodiment of the present disclosure, the second polyol may be a polyester polyol, a polyether polyol, or a C _2-14 polyol. For example, the second polyol may be poly(ethylene adipate) diol or poly(1,4-butanediol adipate) diol ( Poly(1,4-butylene adipate) diol, poly(ethylene dodecanoate) diol, poly(1,6-hexanediol adipate) diol ( Poly(1,6-hexathylene adipate) diol), polyethylene glycol (PEG), polypropylene glycol (PPG), polytetramethylene ether glycol (PTMEG), ethylene Ethylene glycol, 1,3-propylene glycol, glycerol, 1,4-butylene glycol, 1,5-pentanediol (1,5-pentylene glycol), neopentylene glycol, 1,6-hexylene glycol, 1,7-heptylene glycol , 1,8-octylene glycol, 1,9-nonylene glycol, decylene glycol, undecylene glycol ), dodecylene glycol, tetradecylene glycol, rosin-diol, isosorbide Isosorbide), or 2,5-furandiol. According to an embodiment of the present disclosure, the second polyol is a polyester polyol or a polyether polyol, and the number average molecular weight of the second polyol may be 500 to 100000, for example, 500 to 80,000, 1000 to 60,000, 2000 to 50000, or 5000 to 40,000.

According to an embodiment of the present disclosure, the weight ratio of the second polyol to the first polyol may be 0.1 to 0.5 (for example, 0.11, 0.13, 0.15, 0.2, 0.22, 0.25, 0.27, or 0.29) to simultaneously The mechanical strength, the abrasion resistance, and the hydrolysis resistance of the biothermoplastic polyurethane of the present disclosure are improved.

According to an embodiment of the present disclosure, the first polyol may be a polyester polyol, and the second polyol may be a C _2-14 polyol; the first polyol may be a polyester polyol The alcohol, and the second polyol may be a polyether polyol; the first polyol may be a polyether polyol, and the second polyol may be a C _2-14 polyol; The first polyol may be a polyether polyol, and the second polyol may be a polyester polyol.

According to an embodiment of the present disclosure, the diisocyanate may be Hexamethylene Diisocyanate (HDI), methylene diphenyl diisocyanate (MDI), toluene diisocyanate (toluene diisocyanate). , TDI), isophorone diisocyanate (IPDI), 1,5-naphthalene diisocyanate (NDI), p-phenylene diisocyanate , PPDI), or a combination of the above.

According to embodiments of the present disclosure, the composition may comprise two or more diisocyanates.

According to the disclosed embodiment, the modified lignin can be Prepare the steps. First, lignin is reacted with an alkali agent to obtain a mixture. Next, a capping agent is added to the mixture, and the modified lignin is obtained after the reaction.

It is noted that the present disclosure uses a particular base agent to selectively extract hydrogen from the aromatic hydroxyl group and retain the hydrogen of the OH on the aliphatic hydroxyl. Therefore, the modified lignin has an aromatic terminal blocking agent functional group (the hydrogen of the terminal blocking agent functional group substituted for the aromatic hydroxyl group) is larger than the aliphatic terminal blocking agent functional group (the terminal blocking agent functional group replaces the aliphatic hydroxyl group) The number of hydrogen on the).

According to an embodiment of the present disclosure, the alkali agent may be sodium hydroxide, potassium hydroxide, cesium carbonate, potassium carbonate, or a combination thereof. According to an embodiment of the present disclosure, the blocking agent may be XR ¹ , wherein X is halogen, and R ¹ may be C _1-4 alkyl, phenyl, ,or Wherein R ² and R ³ are each independently C _1-4 alkyl; and n is 1, 2, 3 or 4.

According to an embodiment of the present disclosure, the preparation method of the biothermoplastic polyurethane of the present disclosure comprises heating the reaction of the above composition and performing aging. According to an embodiment of the present disclosure, the composition may further comprise 0.01 to 5 parts by weight of a catalyst, and the catalyst may be an organic tantalum catalyst, an organic tin catalyst, or a quaternary ammonium catalyst, wherein the modification The total weight of the lignin and the first polyol is 100 parts by weight.

The above and other objects, features, and advantages of the present invention will become more apparent and understood.

Preparation of modified lignin

Preparation Example 1:

100 parts by weight of lignin (lignin, Mw: 1000-1500, extracted from rice hulls) was added to a reaction flask and dissolved in acetone. After thorough stirring, 120 parts by weight of potassium carbonate was added to the reaction flask at room temperature. Next, after stirring for 30 minutes, 140 parts by weight of methyl iodide was added to the reaction flask at room temperature to convert a part of the hydroxyl groups in the lignin to a methoxy group. After 72 hours of the reaction, a large amount of water was added to the reaction flask to precipitate a solid. After filtration and drying, modified lignin (1) is obtained. The hydroxyl groups remaining in the modified lignin (1) were calculated by nuclear magnetic resonance spectroscopy, and the results are shown in Table 1.

Preparation Example 2:

According to the preparation method of the modified lignin (1) described in Preparation Example 1, except that the reaction time was shortened from 72 hours to 24 hours, modified lignin (2) was obtained. The hydroxyl groups remaining in the modified lignin (2) were calculated by nuclear magnetic resonance spectroscopy, and the results are shown in Table 1.

Biomass thermoplastic polyurethane

Example 1

10 parts by weight of modified lignin (1), and 90 parts by weight of polytetramethylene ether glycol (PTMEG) (sold by Aldrich, number average molecular weight 1000-2000) were placed in a reaction In the bottle. Warming up After 80 ° C, the water was removed by vacuum for one hour. After the reaction flask was purged with argon, 13.5 parts by weight of 1,4-butanediol and 1 part by weight of an organic ruthenium catalyst (manufactured and sold by King Industries, Inc., article numbered as K348) was added to the reaction flask. After thorough stirring, 46.68 parts by weight of isophorone diisocyanate (manufactured and sold by Bayer) was added to the reaction flask and stirring was continued. When the temperature of the reaction flask was raised to 90 ° C - 100 ° C, the stirring was stopped, and the resultant was quickly poured into a mold, and the mold was placed in an oven at 80 ° C. After baking for 16 hours, a biothermoplastic polyurethane (1) was obtained.

Next, the bio-thermoplastic polyurethane (1) was dissolved in dimethyl acetamide and baked into a film by a low-temperature oven (baking temperature: 60-80 ° C). After cutting into test pieces, the 100% modulus (tensile modulus), tensile strength, and tensile elongation were measured by a universal tensile machine according to ASTM D412. The results are shown in Table 2. Shown.

Example 2

The preparation of the biothermoplastic polyurethane (1) according to Example 1 was carried out except that the modified lignin (1) was increased from 10 parts by weight to 20 parts by weight, and the polytetramethylene ether glycol was 90. The weight fraction was reduced to 80 parts by weight to obtain a biomass thermoplastic polyurethane (2). Next, the bio-thermoplastic polyurethane (2) was dissolved in dimethyl acetamide and baked into a film using a low-temperature oven (baking temperature: 60-80 ° C). After cutting into test pieces, the 100% modulus (tensile modulus), tensile strength, and tensile elongation were measured by a universal tensile machine according to ASTM D412. The results are shown in Table 2. Shown.

Comparative example 1

100 parts by weight of polytetramethylene ether glycol (PTMEG) (sold by Aldrich, number average molecular weight 1000-2000) was placed in a reaction flask. After warming to 80 ° C, water was removed by vacuum for one hour. After the reaction flask was purged with argon, 13.5 parts by weight of 1,4-butanediol and 1 part by weight of an organic ruthenium catalyst (manufactured and sold by King Industries, Inc., article numbered as K348) was added to the reaction flask. After thorough stirring, 46.68 parts by weight of isophorone diisocyanate (manufactured and sold by Bayer) was added to the reaction flask and stirring was continued. When the temperature of the reaction flask was raised to 90 ° C - 100 ° C, the stirring was stopped, and the resultant was quickly poured into a mold, and the mold was placed in an oven at 80 ° C. After baking for 16 hours, a polyurethane (1) was obtained. Next, the polyurethane (1) was dissolved in dimethyl acetamide, and baked into a film using a low-temperature oven (baking temperature: 60-80 ° C). After cutting into test pieces, the 100% modulus (tensile modulus), tensile strength, and tensile elongation were measured by a universal tensile machine according to ASTM D412. The results are shown in Table 2. Shown.

Comparative example 2

The preparation of the biothermoplastic polyurethane (2) according to Example 2 was carried out except that the modified lignin (1) was substituted with the modified lignin (2). Since the obtained product is crosslinked and hardened during the ripening process (90 ° C - 100 ° C), it is not thermoplastic and cannot be formed into a film.

Comparative Example 3:

The preparation method of the biothermoplastic polyurethane (2) according to Example 2 is carried out except that the modified lignin (1) is extracted from unmodified lignin (lignin, Mw: 1000-1500, from rice husk) (residue The hydroxyl value is 6.0 mmol/g) generation. Since the obtained product is crosslinked and hardened during the ripening process (90 ° C - 100 ° C), it is not thermoplastic and cannot be formed into a film.

As is clear from Table 2, the addition of the modified lignin (1) (residual hydroxyl value of 2.5 mmol/g) compared with Comparative Example 1 greatly improved the 100% modulus and tensile strength of the obtained biothermoplastic polyurethane. Although the addition of the modified lignin (1) resulted in a decrease in the tensile elongation of the obtained biothermoplastic polyurethane, it was maintained at 700% or more.

Abrasion resistance test

The polyurethane (1) obtained in Comparative Example 1 and the bio-thermoplastic polyurethane (2) obtained in Inventive Example 2 were measured for abrasion loss according to DIN 53516, and the results are shown in Table 3.

As can be seen from Table 3, by adding the modified lignin of the present disclosure, the abrasion resistance of the resulting biothermoplastic polyurethane can be improved.

Hydrolysis resistance test

The biothermoplastic polyurethane (2) obtained in Example 2 was subjected to a hydrolysis resistance test at 80 ° C and 95% RH for 35 days (according to the ASTM D882 standard test method), and the biomass thermoplastic polyurethane (2) was measured. The 100% modulus change rate before and after the hydrolysis resistance test was carried out, and the results are shown in Table 4. The 100% modulus change rate is calculated as follows:

It can be seen from Table 4 that by adding the modified lignin of the present disclosure, the biothermoplastic polyurethane of the present disclosure has good weather resistance, and its mechanical properties are not deteriorated even under high temperature and high humidity environment. .

The present disclosure has been disclosed in the above several embodiments, but it is not intended to limit the disclosure, and any one skilled in the art can make any changes and refinements without departing from the spirit and scope of the disclosure. Therefore, the scope of protection of this disclosure is subject to the definition of the scope of the patent application.

Claims (13)

A bio-thermoplastic polyurethane formed by a reaction of a composition comprising: 1-50 parts by weight of modified lignin, wherein the modified lignin has a hydroxyl value (OH value) of 2 mmol/g to 2.9 mmol/g; 50 to 99 parts by weight of the first polyol, wherein the total weight of the modified lignin and the first polyol is 100 parts by weight; and 40 to 60 parts by weight of diisocyanate. The first item of the raw patent thermoplastic polyurethane mass range, wherein the lignin-based modified lignin at least one terminal functional group (R ^1), and the blocked functional group (R ¹⁾ and lines Residue bond obtained by dehydrogenation of a hydroxyl group on the lignin, wherein the capping functional group (R ¹ ) is a C _1-4 alkyl group, a phenyl group, ,or Wherein R ² and R ³ are each independently C _1-4 alkyl; and n is 1, 2, 3 or 4. The biothermoplastic polyurethane according to claim 2, wherein the lignin is a sulfonate lignin, an alkali lignin, or a combination thereof. The biothermoplastic polyurethane according to claim 1, wherein the first polyol is a polymer polyol. The biothermoplastic polyurethane according to claim 4, wherein the first polyol is a polyester polyol or a polyether polyol. The biothermoplastic polyurethane according to claim 1, wherein The composition further comprises a second polyol, wherein the second polyol is different from the first polyol. The biothermoplastic polyurethane according to claim 6, wherein the second polyol is a polyester polyol, a polyether polyol, or a C _2-14 polyol. The biothermoplastic polyurethane according to claim 6, wherein the weight ratio of the second polyol to the first polyol is from 0.1 to 0.5. The biothermoplastic polyurethane according to claim 8, wherein the first polyol is a polyester polyol, and the second polyol is a polyether of C _2-14 . The biothermoplastic polyurethane according to claim 8, wherein the first polyol is a polyester polyol, and the second polyol polyether polyol. The biothermoplastic polyurethane according to claim 8, wherein the first polyol-based polyether polyol and the second polyol-based C _2-14 polyol. The biothermoplastic polyurethane according to claim 8, wherein the first polyol-based polyether polyol and the second polyol-based polyester polyol. The biothermoplastic polyurethane according to claim 1, wherein the diisocyanate is Hexamethylene Diisocyanate (HDI) or diethylene diphenylmethane (methylene diphenyl). Diisocyanate, MDI), toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), 1,5-naphthalene diisocyanate (NDI) , p-phenylene diisocyanate (PPDI), or a combination thereof.