Polyurethane elastomer composition and application thereof

Abstract

The invention relates to a polyurethane elastomer composition and application thereof. The polyurethane elastomer composition comprises polymer polyol, diisocyanate and cellulose. The polyurethane elastomer composition provided by the embodiment of the invention is used for preparing the polyurethane elastomer, so that the prepared elastomer has excellent degradability and rebound rate.

Description

Technical Field

[0001] The invention relates to a polyurethane elastomer, and in particular to a composition capable of improving the degradability and resilience of the prepared elastomer. Background Art

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

[0003] TPU itself is a degradable material, but conventional TPU has very weak decomposition characteristics and a long degradation cycle. Long-term existence in the natural environment will cause environmental pollution and ecological damage. Currently, low-carbon circular economy has become a global consensus, so accelerating the degradation of TPU materials has become a hot topic.

[0004] The existing TPU has either little improvement in degradation performance; or has poor mechanical properties, which limits the application of the product; or has a complex production process and a high content of by-products. Summary of the invention

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

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

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

[0008] S1: reacting the polymer polyol, diisocyanate and 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 according to one embodiment of the present invention is used to prepare a polyurethane elastomer, so that the prepared elastomer has excellent degradability and resilience. DETAILED DESCRIPTION

[0011] Typical embodiments that embody the features and advantages of the present invention will be described in detail in the following description. It should be understood that the present invention can have various changes in different embodiments without departing from the scope of the present invention, and the descriptions therein are essentially used as illustrations rather than to limit the present invention.

[0012] One embodiment of the present invention provides a polyurethane elastomer composition, including polymer polyol, diisocyanate and cellulose.

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

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

[0015] In one embodiment, the structural formula of cellulose is as follows:

[0016]

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

[0018] In one embodiment, n is selected from 1 to 13000, for example, n may 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 to 1000, for example, x can be 2, 5, 8, 10, 50, 80, 100, 200, 500, or 800.

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

[0021] In one embodiment, the number average molecular weight of cellulose can be 100 to 2,000,000, further can be 200 to 1,500,000, further can be 40,000 to 700,000, and further can be 40,000 to 60,000, for example, 300, 500, 1,000, 3,000, 5,000, 10,000, 45,000, 47,000, 48,000, 49,000, 50,000, 51,000, 52,000, 55,000, 100,000, 1,100,000, and 1,200,000.

[0022] In one embodiment, the composition includes a polymer polyol, a diisocyanate, a cellulose, and a chain extender.

[0023] In one embodiment, the mass content of the polymer polyol in the composition can be 28-72%, for example 30%, 33%, 35%, 38%, 40%, 43%, 45%, 48%, 50%, 53%, 55%, 58%, 60%, 63%, 65%, 68%, 70%, 72%, wherein the above contents are based on the total mass of the composition.

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

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

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

[0027] In one embodiment, the composition includes 28 to 72 wt % of a polymer polyol, 16 to 56 wt % of a diisocyanate, 1 to 50 wt % of a cellulose, and 3 to 20 wt % of a chain extender.

[0028] In one embodiment, the isocyanate index of the composition may be 0.80 to 1.30, and further may be 0.90 to 1.20, such as 1.0 or 1.1.

[0029] In one embodiment, the polymer polyol may be one or more of polyester polyol and polyether polyol.

[0030] In one embodiment, the polyester polyol includes polycarbonate polyol and polycaprolactone polyol.

[0031] In one embodiment, the polymer polyol includes one or more of polytetramethylene glycol, polybutylene adipate glycol, polycarbonate glycol, polyhexane terephthalate glycol, and polyoxypropylene glycol.

[0032] In one embodiment, the number average molecular weight of the polymer polyol can be 800-8000 g / mol, and can further be 1000-6000 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, and 7000 g / mol.

[0033] In one embodiment, the diisocyanate includes one or more of aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate.

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

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

[0036] One embodiment of the present invention provides a polyurethane elastomer, which is prepared by reacting the components of the above composition.

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

[0038] One embodiment of the present invention provides a method for preparing the above-mentioned polyurethane elastomer, comprising the following steps:

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

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

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

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

[0043] In one 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 1-100 s, for example, 2 s, 5 s, 10 s, 15 s, 20 s, 25 s, 30 s, 40 s, 50 s, 60 s, 70 s, 80 s, 90 s.

[0044] In one embodiment, the method for preparing a polyurethane elastomer further comprises step S3: aging and drying the product of step S2 at a temperature of 40 to 110° C. (e.g., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C.). Further, the aging and drying time may be 0.5 to 24 hours, e.g., 1 hour, 2 hours, 3 hours, 5 hours, 8 hours, 10 hours, 12 hours, 15 hours, 18 hours, 20 hours, 22 hours.

[0045] In one embodiment, steps S1 and S2 are performed in a reaction extruder (or extruder), and the product of step S2 can be extruded (eg, extrusion granulated).

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

[0047] S1: After the polymer polyol, diisocyanate and chain extender are stirred and mixed, they are added into a reaction extruder through a first feeding port, a reaction is initiated at a temperature of 80 to 160° C., and the temperature is gradually increased to 160 to 250° C. to allow each component to fully react, thereby obtaining a thermoplastic polyurethane elastomer melt;

[0048] S2: adding cellulose from the second feeding port into the reaction extruder to mix with the thermoplastic polyurethane elastomer melt, continuing the reaction at 160-250° C. to obtain the cellulose-containing thermoplastic polyurethane elastomer, and extruding and granulating;

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

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

[0051] The polyurethane elastomer composition according to one embodiment of the present invention is used to prepare a polyurethane elastomer, so that the prepared elastomer has excellent degradability, resilience and better mechanical properties (such as tensile strength).

[0052] In a polyurethane elastomer composition according to one embodiment of the present invention, the cellulose has high toughness and strength. During the reaction process of preparing the polyurethane elastomer, the hydroxyl groups of the cellulose react with the diisocyanate groups to form chemical bonds, so that the cellulose is connected to the polyurethane elastomer molecular chain, thereby improving the mechanical properties of TPU.

[0053] The (thermoplastic) polyurethane elastomer of one embodiment of the present invention 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 according to one embodiment of the present invention has a high degradation rate, thereby greatly reducing the time required for degradation.

[0055] The preparation of a polyurethane elastomer according to an embodiment of the present invention is further described below in conjunction with examples. The raw materials and test methods involved in each example and comparative example are as follows.

[0056] raw material

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

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

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

[0060] 4. Cellulose: Hydroxypropyl methylcellulose (number average molecular weight of about 50,000) was purchased from Shandong Pingju Biotechnology Co., Ltd.; Hydroxypropyl methylcellulose (number average molecular weight of about 700,000) was purchased from Xi'an Jinxiang Pharmaceutical Excipients Co., Ltd.; Hydroxypropyl methylcellulose (number average molecular weight of about 1,200,000) was purchased from Merck Chemical Co., Ltd.; Cellulose acetate phthalate (number average molecular weight of about 3,000) and cellulose acetate (number average molecular weight of about 50,000) were purchased from Shandong West Asia Chemical Co., Ltd.; Hydroxypropyl methylcellulose acetate succinate (number average molecular weight of about 300) was purchased from Nanjing Bermuda Biotechnology Co., Ltd.; Methylcellulose (number average molecular weight of about 50,000) was purchased from Shanghai MacLean Biochemical Technology Co., Ltd.

[0061] Test Method

[0062] 1. Tensile strength

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

[0064] 2. Degradation performance

[0065] The degradation performance of the polyurethane elastomer is calculated based on the 60-day weight retention rate in a 37°C PBS buffer solution. The specific test method is as follows: (1) The polyurethane elastomer is injection molded into a test piece of 0.2×5×10 cm in size, and the weight of the test piece is recorded before the test; (2) The test piece is completely immersed in a PBS solution, maintained at a room temperature of 37°C, and left for 60 days; (3) The test piece is taken out of the PBS buffer solution, and the weight of the test piece is weighed after drying. The weight of the test piece after the test is divided by the weight before the test to obtain the retention rate.

[0066] 3. Rebound rate

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

[0068] Example 1

[0069] S1: 33 kg of polytetrahydrofuran diol, 49.64 kg of MDI-100 and 15.36 kg of 1,4-butanediol were stirred and mixed, and then added into the reaction extruder through the first feeding port, and the reaction was initiated at a temperature of 140° C., and the temperature was gradually increased to 220° C., and each component was allowed to fully react for 20 seconds to obtain a thermoplastic polyurethane elastomer melt;

[0070] S2: adding 10 kg of cellulose acetate phthalate into the reaction extruder from the second independent feeding port to continue the reaction at a reaction temperature of 230° C., and extruding and granulating after reacting for 15 seconds to obtain cellulose-containing thermoplastic polyurethane elastomer particles;

[0071] S3: The obtained cellulose-containing thermoplastic polyurethane elastomer particles are stored in a silo at 110° C. for continuous maturation and drying for 2 hours to obtain a final product, a polyurethane elastomer.

[0072] Embodiments 2 to 10

[0073] Examples 2 to 10 use substantially the same process steps as Example 1 to prepare polyurethane elastomers, except that the types and amounts of raw materials used and some process parameters are different, see Table 1 for details.

[0074] Table 1 Types, amounts and some process parameters of raw materials in various embodiments

[0075]

[0076] Comparative Example 1

[0077] This example uses substantially the same process and raw materials as Example 1 to prepare a polyurethane elastomer, except that step S2 is not performed. That is, the polyurethane elastomer prepared in this example does not contain cellulose.

[0078] Comparative Example 2

[0079] This example uses substantially the same process and raw materials as Example 2 to prepare a polyurethane elastomer, except that step S2 is not performed. That is, the polyurethane elastomer prepared in this example does not contain cellulose.

[0080] Comparative Example 3

[0081] This example adopts the same process and raw materials as Example 3 to prepare the polyurethane elastomer, the only difference being that the added cellulose is methyl cellulose (number average molecular weight 50,000) which does not contain hydroxyl groups in its structure.

[0082] The polyurethane elastomers prepared in Examples 1 to 10 and Comparative Examples 1 to 3 were subjected to relevant performance tests according to the aforementioned methods. The results are shown in Table 2.

[0083] Table 2 Performance results of polyurethane elastomers obtained in various embodiments and comparative examples

[0084]

[0085] According to the description of Examples 1 to 10, Comparative Examples 1 to 2 and Table 1, compared with Comparative Examples 1 to 2, Examples 1 to 10 also use cellulose raw materials in the preparation process of the polyurethane elastomer. According to the results in Table 2, it can be seen that the polyurethane elastomers prepared in Examples 1 to 10 have a higher degradation rate and a better rebound rate than the polyurethane elastomers in Comparative Examples 1 to 2. Therefore, by introducing cellulose into the polyurethane elastomer in a chemically bonded manner, the degradation rate and rebound rate of the elastomer can be improved.

[0086] According to the description of Example 3 and Comparative Example 3 and Table 1, compared with Comparative Example 3, Example 3 uses cellulose containing hydroxyl groups in the structure in the preparation process of the polyurethane elastomer. According to the results of Table 2, it can be seen that the polyurethane elastomer prepared in Example 3 has a higher degradation rate and better rebound rate and tensile strength than the polyurethane elastomer of Comparative Example 3. Therefore, by introducing cellulose into the polyurethane elastomer in a chemically bonded manner, the degradation rate, rebound rate and tensile strength of the elastomer can be improved.

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

[0088] As shown in Table 1, the only difference between Examples 4, 5, and 9 is that the number average molecular weight of the hypromellose used is different. The number average molecular weight of the hypromellose in Example 4 is 50,000, that in Example 5 is 1,200,000, and that in Example 9 is 700,000. According to the results in Table 2, compared with Example 5, the polyurethane elastomers prepared in Examples 4 and 9 have better degradation performance and resilience, and Example 4 has the best degradation performance and resilience. Therefore, the number average molecular weight of cellulose is preferably 40,000 to 700,000, more preferably 40,000 to 60,000, and even more preferably 50,000.

[0089] As shown in Table 1, the difference between Examples 6, 7 and 10 is that the amount of hypromellose used is different. The amount used in Example 6 is 1 kg, and the mass content in the polyurethane elastomer composition is 1%; the amount used in Example 7 is 20 kg, and the mass content in the polyurethane elastomer composition is 16.7%; the amount used in Example 10 is 40 kg, and 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 rebound rate, and the polyurethane elastomer prepared in Example 10 has better degradation performance and rebound rate. Therefore, the mass content of cellulose in the polyurethane elastomer composition is preferably 15-30%.

[0090] Unless otherwise defined, the terms used in the present invention have the meanings commonly understood by those skilled in the art.

[0091] The embodiments described in the present invention are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Those skilled in the art may make various other substitutions, changes and improvements within the scope of the present invention. Therefore, the present invention is not limited to the above embodiments, but is only limited by the claims.

Claims

1. A polyurethane elastomer composition comprising a polymer polyol, a diisocyanate and cellulose.

2. The composition according to claim 1, wherein The structural formula of the cellulose is as follows: n is an integer ≥ 1, and each of the multiple Rs is independently selected from H, -CH3, x is an integer ≥ 1, wherein multiple R are the same or different, and at least one R is H; and / or, The mass ratio of the polymer polyol, the diisocyanate and the cellulose is (28-72):(16-56):(1-50); and / or, The composition also includes a chain extender.

3. The composition according to claim 1, comprising 28 to 72 wt% of the polymer polyol, 16 to 56 wt% of the diisocyanate, 1 to 50 wt% of the cellulose and 3 to 20 wt% of a chain extender; and / or, The cellulose includes one or more of hydroxypropyl methylcellulose, cellulose acetate phthalate, cellulose acetate, and hydroxypropyl methylcellulose acetate succinate; and / or, The number average molecular weight of the cellulose is 100 to 2,000,000; and / or, The isocyanate index of the composition is 0.80 to 1.

30.

4. The composition according to claim 3, wherein The number average molecular weight of the cellulose is 200 to 1,500,000; and / or, The isocyanate index of the composition is 0.90 to 1.20; and / or, The chain extender includes one or more of 1,4-butanediol, ethylene glycol, 1,3-propylene glycol, methylpropylene glycol, pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, isohexanediol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, p-terephthalimethanol, and 1,4-bis(2-hydroxyethoxy)benzene.

5. The composition according to claim 1, wherein The polymer polyol includes one or more of polyester polyol and polyether polyol; and / or, The number average molecular weight of the polymer polyol is 800 to 8000 g / mol; and / or, The number average molecular weight of the cellulose is 40,000 to 700,000; and / or, The mass content of the cellulose in the composition is 15-30%.

6. The composition according to claim 1, wherein The polymer polyol includes one or more of polycarbonate polyol, polycaprolactone polyol and polyether polyol; and / or, The number average molecular weight of the polymer polyol is 1000 to 6000 g / mol; and / or, The number average molecular weight of the cellulose is 40,000 to 60,000; and / or, The diisocyanate includes one or more of aromatic diisocyanate, aliphatic diisocyanate and alicyclic diisocyanate.

7. The composition according to claim 1, wherein The polymer polyol includes one or more of polytetramethylene glycol, polybutylene adipate glycol, polycarbonate glycol, polyhexane terephthalate glycol, and polyoxypropylene glycol; and / or, The diisocyanate includes 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, and 1,4-cyclohexyl dimethylene diisocyanate.

8. A polyurethane elastomer prepared from the composition according to any one of claims 1 to 7.

9. The method for preparing the polyurethane elastomer according to claim 8, comprising the steps of: S1: reacting the polymer polyol, diisocyanate and chain extender under the action of heating treatment to obtain a polyurethane elastomer melt; S2: reacting the polyurethane elastomer melt with cellulose.

10. The preparation method according to claim 9, wherein: The reaction in step S1 is initiated at a temperature of 80 to 160° C. and carried out at a temperature of 160 to 250° C.; and / or, The reaction temperature of step S2 is 160-250° C.; and / or, Step S1 and step S2 are performed in an extruder, and the product of step S2 is extruded and molded; and / or, The product of step S2 is aged and dried at a temperature of 40 to 110°C.

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