A polyurethane elastomer composition and use thereof

Abstract

The present invention relates to a polyurethane elastomer composition and use thereof, the polyurethane elastomer composition comprising a polymer polyol, a diisocyanate, and cellulose. The polyurethane elastomer composition according to an embodiment of the present invention, when used to prepare a polyurethane elastomer, can provide the prepared elastomer with excellent degradability and resilience.

Description

TECHNICAL FIELD

[0001] The present application relates to polyurethane elastomer, in particular to a composition capable of improving the degradation and resilience of the prepared elastomer. BACKGROUND

[0002] Thermoplastic polyurethane elastomer (TPU) is a multi-block polymer containing soft segments and hard segments, which is a high polymer synthetic material with excellent comprehensive performance, and has excellent mechanical properties such as high strength, high elasticity, high elongation, tear resistance, low temperature resistance and high wear resistance. It also has oil resistance, solvent resistance and chemical resistance, and is widely used in extrusion, casting, blow molding, injection molding, 3D printing and other industries.

[0003] TPU itself belongs to degradable materials, but the conventional TPU has very weak decomposition characteristics, long degradation period, and long-term existence in the natural environment will cause pollution and ecological damage to the environment. At present, low-carbon circular economy has become a global consensus, so accelerating the degradation of TPU materials has become a hot topic at present.

[0004] The existing TPU or degradation performance is not obvious; or the mechanical properties are poor, which limits the application of the product to a certain extent; or the production process is complex, and the byproduct content is high. SUMMARY

[0005] In order to overcome at least one of the above-mentioned defects of the prior art, in a first aspect, an embodiment of the present application provides a polyurethane elastomer composition, comprising a polymer polyol, a diisocyanate and cellulose.

[0006] In a second aspect, an embodiment of the present application provides a polyurethane elastomer prepared by the above-mentioned composition.

[0007] In a third aspect, an embodiment of the present application provides a preparation method of the above-mentioned polyurethane elastomer, comprising the following steps:

[0008] S1: reacting the polymer polyol, the diisocyanate and the chain extender under the action of heating treatment to obtain a polyurethane elastomer melt;

[0009] S2: reacting the polyurethane elastomer melt with cellulose.

[0010] The polyurethane elastomer composition of an embodiment of the present application can be used to prepare a polyurethane elastomer, so that the prepared elastomer has excellent degradability and resilience. DETAILED DESCRIPTION

[0011] The exemplary embodiments embodying the features and advantages of the present application will be described in detail hereinafter. It should be understood, however, that the application can be practiced with various modifications and alterations within the scope thereof and such descriptions are thus to be understood as being by way of illustration only and not as limiting the application as defined in the appended claims.

[0012] One embodiment of the present application provides a polyurethane elastomer composition comprising a polymeric polyol, a diisocyanate, and a cellulose.

[0013] In one embodiment, the mass ratio of the polymeric polyol, the diisocyanate, and the cellulose can be (28-72):(16-56):(1-50).

[0014] In one embodiment, the cellulose comprises a hydroxyl group.

[0015] In one embodiment, the cellulose has the following structural formula:

[0016]

[0017] n is an integer ≥ 1, and each of the plurality of R is independently selected from H, -CH3, x is an integer ≥ 1, wherein the plurality of R are the same or different, and at least one R is H.

[0018] In one embodiment, n is selected from 1-13000, for example, n can be 2, 5, 8, 10, 50, 80, 100, 200, 500, 800, 1000, 2000, 5000, 8000, or 10000.

[0019] In one embodiment, x is selected from 1-1000, for example, x can be 2, 5, 8, 10, 50, 80, 100, 200, 500, 800.

[0020] In one embodiment, the cellulose comprises one or more of hydroxypropyl methylcellulose (HPMC), cellulose acetate phthalate (CAP), cellulose acetate, hydroxypropyl methylcellulose acetate succinate (HPMCAS).

[0021] In one embodiment, the number average molecular weight of the cellulose can be 100-2000000, further can be 200-1500000, more further can be 40000-700000, again further can be 40000-60000, for example, 300, 500, 1000, 3000, 5000, 10000, 45000, 47000, 48000, 49000, 50000, 51000, 52000, 55000, 100000, 1100000, 1200000.

[0022] In an embodiment, the composition comprises a polymeric polyol, a diisocyanate, cellulose, and a chain extender.

[0023] In an embodiment, the polymeric polyol can have a mass content in the composition of 28-72%, for example 30%, 33%, 35%, 38%, 40%, 43%, 45%, 48%, 50%, 53%, 55%, 58%, 60%, 63%, 65%, 68%, 70%, 72%, based on the total mass of the composition.

[0024] In an embodiment, the diisocyanate can have a mass content in the composition of 16-56%, for example 18%, 20%, 23%, 25%, 30%, 33%, 35%, 38%, 40%, 43%, 45%, 48%, 50%, 53%, 56%, based on the total mass of the composition.

[0025] In an embodiment, the cellulose can have a mass content in the composition of 1-50%, further 15-30%, for example 1%, 3%, 8%, 10%, 13%, 18%, 20%, 23%, 28%, 30%, 33%, 38%, 40%, 43%, 48%, 50%, based on the total mass of the composition.

[0026] In an embodiment, the chain extender can have a mass content in the composition of 3-20%, for example 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, based on the total mass of the composition.

[0027] In an embodiment, the composition comprises 28-72 wt% of a polymeric polyol, 16-56 wt% of a diisocyanate, 1-50 wt% of cellulose, and 3-20 wt% of a chain extender.

[0028] In an embodiment, the composition can have an isocyanate index of 0.80-1.30, further 0.90-1.20, for example 1.0, 1.1.

[0029] In an embodiment, the polymeric polyol can be one or more of a polyester polyol, a polyether polyol.

[0030] In an embodiment, the polyester polyol comprises a polycarbonate polyol and a polycaprolactone polyol.

[0031] In an embodiment, the polymeric polyol comprises one or more of polytetrahydrofuran diol, polybutylene adipate diol, polycarbonate diol, poly-1,6- hexanediol terephthalate diol, polypropylene oxide diol.

[0032] In an embodiment, the polymeric polyol has a number average molecular weight of 800 to 8000 g / mol, further 1000 to 6000 g / mol, for example 1500 g / mol, 2000 g / mol, 2500 g / mol, 3000 g / mol, 3500 g / mol, 4000 g / mol, 4500 g / mol, 5000 g / mol, 5500 g / mol, 6500 g / mol, 7000 g / mol.

[0033] In an embodiment, the diisocyanate comprises one or more of aromatic diisocyanate, aliphatic diisocyanate, cycloaliphatic diisocyanate.

[0034] In an embodiment, the diisocyanate is aromatic diisocyanate or aliphatic diisocyanate, the aromatic diisocyanate can be one or more of diphenylmethane diisocyanate, toluene diisocyanate, 1,5-naphthalene diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, the cycloaliphatic diisocyanate, aliphatic diisocyanate can be one or more of hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, isophorone diisocyanate, 1,4-cyclohexyl dimethylene diisocyanate. Further, the diisocyanate comprises diphenylmethane diisocyanate (MDI) and / or hexamethylene diisocyanate (HDI).

[0035] In an embodiment, the chain extender comprises one or more of 1,4-butanediol, ethylene glycol, 1,3-propanediol, methylpropanediol, pentanediol (e.g. neopentyl glycol), 3-methyl-1,5-pentanediol, 1,6-hexanediol, isohexanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, p-xylyleneglycol, 1,4-bis(2-hydroxyethoxy)benzene.

[0036] An embodiment of the present application provides a polyurethane elastomer prepared by reacting the components of the above composition.

[0037] In an embodiment, the polymeric polyol, the diisocyanate and the chain extender are first reacted to prepare a polyurethane, and then the polyurethane is reacted with cellulose to obtain the polyurethane elastomer material.

[0038] An embodiment of the present application provides a method for preparing the above polyurethane elastomer, comprising the following steps:

[0039] S1: reacting the polymer polyol, the diisocyanate and the chain extender under the action of heat treatment to obtain a polyurethane elastomer melt;

[0040] S2: reacting the polyurethane elastomer melt with the cellulose.

[0041] In an embodiment, the reaction of step S1 is initiated at a temperature of 80-160°C, for example, the initiation temperature can be 90°C, 100°C, 110°C, 120°C, 130°C, 140°C, 150°C.

[0042] In an embodiment, the reaction of step S1 is carried out at a temperature of 160-250°C, for example, the reaction temperature can be 170°C, 180°C, 200°C, 210°C, 220°C, 230°C, 240°C. The reaction time of step S1 can be 5-600s, for example, 10s, 20s, 30s, 40s, 50s, 60s, 80s, 100s, 150s, 200s, 250s, 300s, 350s, 400s, 450s, 500s, 550s.

[0043] In an embodiment, the reaction temperature of step S2 can be 160-250°C, for example, 170°C, 180°C, 200°C, 210°C, 220°C, 230°C, 240°C. The reaction time of step S2 can be 1-100s, for example, 2s, 5s, 10s, 15s, 20s, 25s, 30s, 40s, 50s, 60s, 70s, 80s, 90s.

[0044] In an embodiment, the method for preparing the polyurethane elastomer further comprises step S3: curing and drying the product of step S2 at a temperature of 40-110°C (for example, 50°C, 60°C, 70°C, 80°C, 90°C, 100°C). Further, the curing and drying time can be 0.5-24h, for example, 1h, 2h, 3h, 5h, 8h, 10h, 12h, 15h, 18h, 20h, 22h.

[0045] In an embodiment, steps S1, S2 are carried out in a reaction extruder (or extruder), and the product of step S2 can be extruded (for example, extruded into granules).

[0046] In an embodiment, the method for preparing the polyurethane elastomer comprises:

[0047] S1: stirring and mixing the polymer polyol, the diisocyanate and the chain extender, then adding them into a reaction extruder through a first feeding port, initiating the reaction at a temperature of 80-160°C, gradually increasing the temperature to 160-250°C, and allowing the components to fully react to obtain a thermoplastic polyurethane elastomer melt;

[0048] S2: cellulose is added from the second feeding port into the reaction extruder to mix with the thermoplastic polyurethane elastomer melt, and the reaction is continued at 160-250°C to obtain a thermoplastic polyurethane elastomer containing cellulose, which is extruded and granulated;

[0049] S3: the polyurethane elastomer granules obtained in step S2 are stored in a bin at 40-110°C for continuous curing and drying to obtain the target product.

[0050] In one embodiment, 0-150 ppm of catalyst is added in the preparation of the polyurethane elastomer for adjusting the reaction rate of diisocyanate with the compound containing active hydrogen (polymer polyol and chain extender), the amount of catalyst being based on the total mass of the polyurethane elastomer; the catalyst can be added in step S1. Further, when the reaction time (i.e. the reaction time in step S1) is greater than 180 seconds, a catalyst for promoting the reaction is selected, and when the reaction time is less than 30 seconds, a catalyst for inhibiting the reaction is selected. The catalyst for promoting the reaction can be one or more of organic acid salts, inorganic acid salts and organic metal derivatives of tin, iron, bismuth, cobalt, zinc, copper, nickel, molybdenum, zirconium, aluminum; preferably, the catalyst is one or more of organic tin catalysts, more preferably one or more of stannous octoate, dibutyltin dioctoate, dibutyltin dilaurate. The catalyst for inhibiting the reaction can be one or more of protonic acids containing free active H + , such as one or more of dilute sulfuric acid, phosphoric acid, sulfonic acid, preferably phosphoric acid.

[0051] The polyurethane elastomer composition of one embodiment of the present application, when used for preparing a polyurethane elastomer, can make the prepared elastomer have excellent degradability, resilience and better mechanical properties (such as tensile strength).

[0052] The polyurethane elastomer composition of one embodiment of the present application has cellulose with higher toughness and strength, and in the reaction process for preparing the polyurethane elastomer, the hydroxyl groups of the cellulose will react with the diisocyanate groups to form chemical bonds, so that the cellulose is connected to the molecular chain of the polyurethane elastomer, thereby improving the mechanical properties of the TPU.

[0053] The (thermoplastic) polyurethane elastomer of one embodiment of the present application can be prepared by a one-step method, the production process is simple, and the polyurethane elastomer has excellent degradability, resilience and mechanical properties.

[0054] The polyurethane elastomer of one embodiment of the present application has a higher degradation rate, thereby greatly reducing the time required for degradation.

[0055] Hereinafter, the preparation of the polyurethane elastomer of one embodiment of the present application is further described in conjunction with examples. The raw materials and test methods involved in each example and comparative example are as follows.

[0056] Raw materials

[0057] 1. Polymer polyol: polytetrahydrofuran diol (99.9% active ingredient content, number average molecular weight about 1000), purchased from Jinan Guangyu Chemical Co., Ltd.; polybutylene adipate diol (99% active ingredient content, number average molecular weight about 2000), purchased from Wanhua Chemical.

[0058] 2. Chain extender: 1,4-butanediol (99.7% active ingredient), purchased from Wanhua Chemical.

[0059] 3. Diisocyanate: diphenylmethane diisocyanate MDI-100 (≥99% active ingredient), hexamethylene diisocyanate HT-100 (≥99% active ingredient), purchased from Wanhua Chemical.

[0060] 4. Cellulose: hypromellose (number average molecular weight about 50000), purchased from Shandong Pinggu Biological Technology Co., Ltd.; hypromellose (number average molecular weight about 700000), purchased from Xi'an Jinxiang Pharmaceutical Auxiliary Material Co., Ltd.; hypromellose (number average molecular weight about 1200000), purchased from Merck Chemical Co., Ltd.; cellulose acetate phthalate (number average molecular weight about 3000) and cellulose acetate (number average molecular weight about 50000), purchased from Shandong Xiyachem Co., Ltd.; hydroxypropyl methyl cellulose acetate succinate (number average molecular weight about 300), purchased from Nanjing Bemoda Biological Technology Co., Ltd.; methyl cellulose (number average molecular weight about 50000), purchased from Shanghai Maikelin Biochemical Technology Co., Ltd.

[0061] Test methods

[0062] 1. Tensile strength

[0063] The tensile strength of the polyurethane elastomer is measured according to the GB / T 528-2009 standard.

[0064] 2. Degradation performance

[0065] The degradation performance of the polyurethane elastomer is calculated according to the weight retention rate in PBS buffer solution at 37℃ for 60 days, and the specific test method is as follows: (1) the polyurethane elastomer is injection molded into a test piece with a size of 0.2x5x10cm, and the weight of the test piece is recorded before testing; (2) the test piece is completely immersed in PBS solution, kept at room temperature 37℃, and placed for 60 days; (3) the test piece is taken out from the PBS buffer solution, dried and weighed, and the weight of the test piece after testing is divided by the weight before testing to obtain the retention rate.

[0066] 3. Resilience

[0067] The resilience of the polyurethane elastomer is measured according to the GB / T 1681 standard.

[0068] Example 1

[0069] S1: After stirring and mixing polytetrahydrofuran diol 33 kg, MDI-100 49.64 kg and 1,4-butanediol 15.36 kg, the mixture was added into the reaction extruder through the first feeding port, the reaction was initiated at a temperature of 140°C, the temperature was gradually increased to 220°C, and the components were fully reacted for 20 s, to obtain a thermoplastic polyurethane elastomer melt;

[0070] S2: Cellulose acetate phthalate 10 kg was added into the reaction extruder from the second independent feeding port for continuous reaction, the reaction temperature was 230°C, and the reaction was carried out for 15 s, and then the extrusion granulation was carried out, to obtain cellulose-containing thermoplastic polyurethane elastomer particles;

[0071] S3: The cellulose-containing thermoplastic polyurethane elastomer particles obtained were stored in a bin at 110°C for continuous curing and drying for 2 h, to obtain the final product polyurethane elastomer.

[0072] Examples 2-10

[0073] Examples 2-10 were prepared by using the same process steps as Example 1, except that the types and amounts of raw materials and some process parameters were different, as shown in Table 1.

[0074] Table 1: Types and amounts of raw materials and some process parameters of each example

[0075]

[0076] Comparative Example 1

[0077] In this example, the polyurethane elastomer was prepared by using the same process and raw materials as Example 1, except that step S2 was not performed. That is, the polyurethane elastomer prepared in this example does not contain cellulose.

[0078] Comparative Example 2

[0079] In this example, the polyurethane elastomer was prepared by using the same process and raw materials as Example 2, except that step S2 was not performed. That is, the polyurethane elastomer prepared in this example does not contain cellulose.

[0080] Comparative Example 3

[0081] In this example, the polyurethane elastomer was prepared by using the same process and raw materials as Example 3, except that the cellulose added was methyl cellulose (number average molecular weight 50000) which did not contain hydroxyl groups in the structure.

[0082] The polyurethane elastomers prepared from Examples 1-10 and Comparative Examples 1-3 were tested for relevant properties according to the aforementioned method, and the results are shown in Table 2.

[0083] Table 2: Properties of polyurethane elastomers prepared from Examples and Comparative Examples

[0084]

[0085] According to the descriptions of Examples 1-10 and Comparative Examples 1-2 and Table 1, compared with Comparative Examples 1-2, Examples 1-10 further used cellulose raw materials in the preparation of polyurethane elastomers. According to the results in Table 2, it can be seen that the polyurethane elastomers prepared from Examples 1-10 have higher degradation rates and better resilience rates compared with the polyurethane elastomers of Comparative Examples 1-2. Therefore, by introducing cellulose into the polyurethane elastomer in a chemical bond manner, the degradation rate and resilience rate of the elastomer can be improved.

[0086] According to the descriptions of Examples 3 and Comparative Example 3 and Table 1, compared with Comparative Example 3, Example 3 used cellulose containing hydroxyl groups in the structure in the preparation of polyurethane elastomers. According to the results in Table 2, it can be seen that the polyurethane elastomer prepared from Example 3 has a higher degradation rate and better resilience rate and tensile strength compared with the polyurethane elastomer of Comparative Example 3. Therefore, by introducing cellulose into the polyurethane elastomer in a chemical bond manner, the degradation rate and resilience rate and tensile strength of the elastomer can be improved.

[0087] According to Table 1, the difference between Examples 2 and 3 is only that the types of cellulose used are different, Example 2 uses cellulose acetate, and Example 3 uses hydroxypropyl methyl cellulose with the same molecular weight. According to the results in Table 2, compared with Example 2, the polyurethane elastomer prepared from Example 3 has better tensile strength, degradation performance and resilience rate. Therefore, the cellulose used to prepare the polyurethane elastomer is more preferably hydroxypropyl methyl cellulose.

[0088] According to Table 1, the difference between Examples 4, 5 and 9 is only that the number average molecular weight of the hydroxypropyl methyl cellulose used is different. The number average molecular weight of the hydroxypropyl methyl cellulose in Example 4 is 50000, in Example 5 is 1200000, and in Example 9 is 700000. According to the results in Table 2, compared with Example 5, the polyurethane elastomers prepared from Examples 4 and 9 have better degradation performance and resilience rate, and Example 4 has the best degradation performance and resilience rate. Therefore, the number average molecular weight of the cellulose is preferably 40000-700000, further preferably 40000-60000, and more further preferably 50000.

[0089] As shown in Table 1, the difference between Examples 6, 7 and 10 is only in the amount of hydroxypropyl methyl cellulose used. The amount of hydroxypropyl methyl cellulose used in Example 6 is 1 kg, the mass content in the polyurethane elastomer composition is 1%; the amount of hydroxypropyl methyl cellulose used in Example 7 is 20 kg, the mass content in the polyurethane elastomer composition is 16.7%; the amount of hydroxypropyl methyl cellulose used in Example 10 is 40 kg, the mass content in the polyurethane elastomer composition is 28.6%. According to the results in Table 2, compared with Example 6, the polyurethane elastomer prepared in Example 7 has better tensile strength, degradation performance and resilience, and the polyurethane elastomer prepared in Example 10 has better degradation performance and resilience. Therefore, the mass content of cellulose in the polyurethane elastomer composition is preferably 15-30%.

[0090] Unless otherwise defined, all terms used in disclosing the application, including technical and scientific terms, have the meaning commonly understood by one of ordinary skill in the art to which this application belongs.

[0091] The embodiments described herein are only for illustrative purposes, and are not intended to limit the scope of protection of the application. Those skilled in the art can make various other replacements, changes and improvements within the scope of the application, and therefore the application is not limited to the above-described embodiments, but is only limited by the claims.

Claims

1. A polyurethane elastomer made from a polyurethane elastomer composition; the polyurethane elastomer composition comprising 28 to 72 wt% of a polymeric polyol, 16 to 56 wt% of a diisocyanate, 8 to 40 wt% of a cellulose, and 3 to 20 wt% of a chain extender; wherein, The polyurethane elastomer is prepared by first reacting a polymeric polyol, a diisocyanate and a chain extender to form a polyurethane, and then reacting the polyurethane with cellulose; The cellulose comprises one or more of hypromellose, cellulose acetate phthalate, cellulose acetate, hypromellose acetate succinate, and the cellulose comprises hydroxyl groups; the cellulose has a number average molecular weight of 300-1,200,000.

2. The polyurethane elastomer of claim 1, wherein, The composition has an isocyanate index of 0.80-1.

30.

3. The polyurethane elastomer of claim 1, wherein, The composition has an isocyanate index of 0.90-1.20; and / or, The chain extender comprises one or more of 1,4-butanediol, ethylene glycol, 1,3-propanediol, methylpropanediol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, isohexanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, p-xylylene glycol, 1,4-bis(2-hydroxyethoxy)benzene.

4. The polyurethane elastomer of claim 1, wherein, The polymeric polyol comprises one or more of a polyester polyol, a polyether polyol; and / or, The polymeric polyol has a number average molecular weight of 800-8,000 g / mol; and / or, The cellulose has a number average molecular weight of 40,000-700,000; and / or, The cellulose has a mass content of 15-30% in the composition.

5. The polyurethane elastomer of claim 1, wherein, The polymeric polyol comprises one or more of a polycarbonate polyol, a polycaprolactone polyol, a polyether polyol; and / or, The polymeric polyol has a number average molecular weight of 1,000-6,000 g / mol; and / or, The cellulose has a number average molecular weight of 40,000-60,000; and / or, The diisocyanate comprises one or more of an aromatic diisocyanate, an aliphatic diisocyanate, a cycloaliphatic diisocyanate.

6. The polyurethane elastomer of claim 1, wherein, The polymeric polyol comprises one or more of polytetrahydrofuran diol, polybutylene adipate diol, polycarbonate diol, poly-1,6-hexanediol terephthalate diol, polypropylene oxide diol; and / or, The diisocyanate comprises one or more of diphenylmethane diisocyanate, toluene diisocyanate, 1,5-naphthalene diisocyanate, p-phenylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, isophorone diisocyanate, 1,4-cyclohexyl dimethylene diisocyanate.

7. A method for preparing the polyurethane elastomer of any one of claims 1-6, comprising the following steps: S1: reacting the polymeric polyol, the diisocyanate and the chain extender under the action of heat treatment to obtain a polyurethane elastomer melt; S2: reacting the polyurethane elastomer melt with the cellulose.

8. The production method according to claim 7, wherein The reaction of step S1 is initiated at a temperature of 80-160°C and is carried out at a temperature of 160-250°C; and / or, The reaction temperature of step S2 is 160-250°C; and / or, Step S1, step S2 are carried out in an extruder, and the product of step S2 is extruded into a shape; and / or, The product of step S2 is subjected to curing and drying at a temperature of 40-110°C.

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