A polyurethane transparent elastomer and a method for preparing the same

Abstract

The application discloses a kind of polyurethane transparent elastomer and preparation method thereof, it is related to polyurethane elastomer technical field, its preparation method includes the following steps: polytetrahydrofuran ether glycol-2000, polytetrahydrofuran ether glycol-1000 vacuum dehydration, standby;The reaction container is preheated, and isophorone diisocyanate, benzoyl chloride is added, is stirred evenly, and polytetrahydrofuran ether glycol-2000, polytetrahydrofuran ether glycol-1000 is added, and heat preservation reaction is carried out, to obtain polyurethane prepolymer;Polyether polyol N330, chain extender, dibutyltin dilaurate, silicone oil, defoaming agent, antioxidant and ultraviolet absorber are stirred evenly, vacuum degassing, added into polyurethane prepolymer, stirred evenly, poured into mould, solidification forming, demolding, to obtain polyurethane transparent elastomer.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane elastomers, in particular to a polyurethane transparent elastomer and a preparation method thereof. BACKGROUND

[0002] With the continuous development of science and technology, the requirements for the comprehensive performance of materials are continuously improving, especially in high-end applications such as clothing and walking, not only excellent mechanical properties (such as wear resistance, elasticity, comfort), high transparency and excellent weather resistance are required, but also higher expectations for the sustainability of materials are put forward. Traditional polyurethane elastomers are widely used in shoe materials due to their good wear resistance, elasticity and wearing comfort. However, the polyurethane elastomers in the prior art mainly rely on petroleum-based raw materials, which have two major limitations: on the one hand, they still have deficiencies in key optical transparency, long-term weather resistance (such as anti-yellowing and anti-ultraviolet aging) and comprehensive mechanical property balance, which limits their application potential in high-end transparent soles, fashionable functional shoe materials and other fields; on the other hand, their raw materials are highly dependent on non-renewable petrochemical resources, which does not meet the urgent needs of the current industry for environmental protection, sustainable development and reduction of carbon footprint.

[0003] Therefore, the development of a new type of polyurethane transparent elastomer not only needs to break through the bottleneck of traditional materials in transparency, weather resistance and mechanical properties to meet the stringent requirements of high-end shoe materials, but also urgently needs to explore a feasible path to replace petroleum-based raw materials with renewable biomass resources. The development of such a renewable resource-based polyurethane transparent elastomer has important technical value, environmental benefits and industrial significance for improving shoe material performance, promoting the green and low-carbon transformation of the shoe industry, and reducing dependence on traditional petroleum products. SUMMARY

[0004] The purpose of the present application is to provide a polyurethane transparent elastomer and a preparation method thereof to solve the problems in the prior art.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] A preparation method of a polyurethane transparent elastomer, comprising the following steps:

[0007] S1: polytetrahydrofuran ether diol-2000, polytetrahydrofuran ether diol-1000 are heated to 120-130℃ and vacuum dehydrated for 1-2h, cooled to 65-75℃, and standby; the reaction vessel is preheated to 70-75℃, isophorone diisocyanate and benzoyl chloride are added, heated to 80-90℃, stirred uniformly, polytetrahydrofuran ether diol-2000 and polytetrahydrofuran ether diol-1000 are added, and the reaction is kept for 2-3h to obtain a polyurethane prepolymer;

[0008] S2: Stir the polyether polyol N330, chain extender, dibutyltin dilaurate, silicone oil, defoaming agent, antioxidant and ultraviolet absorber uniformly, vacuum degassing, adding into the polyurethane prepolymer, stirring uniformly, pouring into the mold, 80-100℃, 60-80bar curing molding, demolding, obtaining the polyurethane transparent elastomer;

[0009] The proportion of each component in the polyurethane transparent elastomer, by mass fraction, includes: polytetrahydrofuran ether diol-2000 10-16 parts, polytetrahydrofuran ether diol-1000 14-16 parts, isophorone diisocyanate 20-24 parts, benzoyl chloride 0.2-0.3 parts, polyether polyol N330 8-12 parts, chain extender 4-8 parts, dibutyltin dilaurate 0.01-0.02 parts, silicone oil 0.5-1 parts, defoaming agent 0.6-1.2 parts, antioxidant 0.4-0.8 parts and ultraviolet absorber 0.2-0.6 parts;

[0010] The chain extender includes organosilicon chain extender, POSS polyol chain extender and 1,4-butanediol; wherein the mass ratio of organosilicon chain extender, POSS polyol chain extender and 1,4-butanediol is (2-4):(1-3):1;

[0011] The preparation method of the organosilicon chain extender comprises the following steps: step (1): adding KH550 into chloroform, adding polyformaldehyde, stirring uniformly, adding vanillin trichloromethane solution, heating to reflux reaction for 36-38h, cooling to room temperature, filtering, using 0.3mol / L sodium hydroxide solution and deionized water to wash the product, drying with anhydrous sodium sulfate, filtering, rotary evaporation, vacuum drying at 70-75℃ for 2-2.5h, obtaining vanillin organosilicon monomer;

[0012] In the preparation process of the vanillin organosilicon monomer, the molar ratio of KH550:polyformaldehyde:vanillin is 1:5:1;

[0013] Step (2): adding ethanolamine into N,N-dimethylformamide, stirring uniformly, adding vanillin organosilicon monomer, heating to 70-75℃ for 5-5.5h, vacuum filtering, drying, grinding, obtaining ethanolamine intermediate;

[0014] In the preparation process of the ethanolamine intermediate, the molar ratio of ethanolamine:vanillin organosilicon monomer is (2-3):1;

[0015] Step (3): adding ethanolamine intermediate, octamethylcyclotetrasiloxane, hexamethyldisiloxane and triflic acid into deionized water, heating to 80-85℃ for 5-5.5h, cooling to room temperature, using 75wt% ethanol to wash the product, vacuum distillation at 75-76℃ and-0.1MPa, obtaining organosilicon chain extender;

[0016] The molar ratio of the ethanolamine intermediate: octamethylcyclotetrasiloxane: hexamethyl disiloxane in the preparation process of the silicone chain extender is 1:(2-5):(3-5);

[0017] The preparation method of the POSS polyol chain extender comprises the following steps: vanillin and potassium carbonate are added into tetrahydrofuran, stirred uniformly, a tetrahydrofuran solution of chloropropyl POSS is added, heated to 80-85 DEG C to reflux for 2-2.5 h, the mixture is poured into deionized water, the product is filtered, and the product is sequentially washed with 0.01 mol / L hydrochloric acid solution and deionized water until neutral, and vacuum dried at 70-75 DEG C to obtain polyaldehyde modified POSS.

[0018] The molar ratio of vanillin: potassium carbonate: chloropropyl POSS in the preparation process of the polyaldehyde modified POSS is (8-9):(8-9):1.

[0019] Vanillin and potassium carbonate are added into tetrahydrofuran, stirred uniformly, a tetrahydrofuran solution of chloropropyl POSS is added, heated to 80-85 DEG C to reflux for 2-2.5 h, the mixture is poured into deionized water, the product is filtered, and the product is sequentially washed with 0.01 mol / L hydrochloric acid solution and deionized water until neutral, and vacuum dried at 70-75 DEG C to obtain polyaldehyde modified POSS.

[0020] The mass ratio of the polyaldehyde modified POSS: hydroxylamine hydrochloride in the preparation process of the POSS polyol chain extender is 5:(2-3).

[0021] The polyether polyol N330 specification: trifunctional, Mn=3000.

[0022] The silicone oil is DOWSIL TM 1248 Fluid.

[0023] The defoaming agent is byk-1790.

[0024] The antioxidant is antioxidant 168.

[0025] The ultraviolet absorber is UV-P.

[0026] Compared with the prior art, the present application has the following advantages:

[0027] 1、The lignin derivative vanillin is used as a bio-based raw material, and the vanillin derivative prepared by the lignin derivative vanillin is used as a chain extender in the preparation process of the polyurethane elastomer, so that the purpose of replacing petroleum and reducing the dependence on petroleum resources is achieved, and the mechanical properties, wear resistance and yellowing resistance of the polyurethane elastomer are enhanced while the high transparency of the polyurethane elastomer is maintained.

[0028] 2、The present application uses vanillin as raw material to prepare a benzoxazine monomer containing siloxane, further reacts it with ethanolamine to graft hydroxyl groups on its surface to prepare an ethanolamine intermediate; finally, the siloxane-containing ethanolamine intermediate, octamethylcyclotetrasiloxane and hexamethyl disiloxane are used as raw materials to copolymerize to prepare a polysiloxane chain extender containing benzoxazine side chains; the polysiloxane chain extender is used as a chain extender to introduce a flexible polysiloxane long chain and a rigid benzoxazine structure into a polyurethane elastomer, and the polysiloxane long chain is used as part of a soft segment to provide flexible spacing and low surface energy characteristics.

[0029] 3、The present application uses vanillin as raw material, grafts it on the surface of chloropropyl POSS, and then reduces the aldehyde group on the surface to a hydroxyl group through a redox reaction of hydroxylamine hydrochloride to prepare a POSS polyol chain extender; the POSS is used as a rigid nanofiller, and is introduced into the polyurethane elastomer by acting as a chain extender, which can effectively transfer stress, hinder chain segment movement, improve wear resistance, strength and heat resistance, increase crosslinking density, and improve the rigidity and solvent resistance of the material; on the other hand, the inorganic Si-O-Si skeleton has excellent shielding and absorption effects on ultraviolet light, which can effectively protect the polyurethane molecular chain from ultraviolet radiation degradation, and further improve the weather resistance and anti-yellowing property of the material.

[0030] 4、The present application further adjusts the ratio between the two chain extenders, uses the migration of the siloxane segment to the surface to provide hydrophobicity, and uses the POSS to provide thermal stability and enhancement in the near-surface region or inside to jointly improve the surface performance and overall durability; at the same time, the long-chain siloxane provides flexibility and elasticity, and the POSS provides rigidity and enhancement, and the adjustment of the ratio of the two achieves a good balance between rigidity and toughness of the polyurethane elastomer material. DETAILED DESCRIPTION

[0031] The technical solutions in the embodiments of the present application will be clearly and completely described below, obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0032] In the following embodiments, the preparation method of the organosilicon chain extender comprises the following steps: 0.1 mol of KH550 is added to chloroform, 0.5 mol of polyformaldehyde is added, stirred uniformly, 0.1 mol of vanillin is added to the chloroform solution, heated to reflux for 36 h, cooled to room temperature, filtered, the product is washed with 0.3 mol / L sodium hydroxide solution and deionized water, dried with anhydrous sodium sulfate, filtered, rotary evaporated, and vacuum dried at 70℃ for 2 h to obtain a vanillin organosilicon monomer;

[0033] 0.2 mol of ethanolamine was added into N,N-dimethylformamide, stirred uniformly, 0.11 mol of vanillin organosilicon monomer was added, heated to 70 DEG C for 5 h, vacuum filtration, drying, grinding, to obtain the ethanolamine intermediate;

[0034] 1 mol of ethanolamine intermediate, 2 mol of octamethylcyclotetrasiloxane, 3 mol of hexamethyldisiloxane, trifluoromethanesulfonic acid were added into deionized water, heated to 80 DEG C for 5 h, cooled to room temperature, the product was washed with 75 wt% ethanol, vacuum distilled at 75 DEG C and-0.1 MPa to obtain the organosilicon chain extender;

[0035] The preparation method of the POSS polyol chain extender comprises the following steps: 0.8 mol of vanillin and 0.8 mol of potassium carbonate were added into tetrahydrofuran, stirred uniformly, 1 mol of chloropropyl POSS was added into tetrahydrofuran solution, heated to 80 DEG C for refluxing for 2 h, the mixture was poured into deionized water, filtered, the product was washed with 0.01 mol / L hydrochloric acid solution and deionized water in sequence until neutral, and vacuum dried at 70 DEG C to obtain the polyaldehyde modified POSS;

[0036] 5 g of the polyaldehyde modified POSS and 2 g of hydroxylamine hydrochloride were added into pyridine, heated to 115 DEG C for refluxing for 3 h, cooled to room temperature, the mixture was poured into deionized water, filtered, washed with ethanol and n-hexane mixed solution with a volume ratio of 1:1, and vacuum dried at 60 DEG C to obtain the POSS polyol chain extender.

[0037] Embodiment 1: A preparation method of a polyurethane transparent elastomer comprises the following steps: S1: 10 parts of polytetrahydrofuran ether diol-2000 and 14 parts of polytetrahydrofuran ether diol-1000 were heated to 120 DEG C for vacuum dehydration for 1 h, cooled to 65 DEG C, and reserved; a reaction container was preheated to 70 DEG C, 20 parts of isophorone diisocyanate and 0.2 parts of benzoyl chloride were added, heated to 80 DEG C, stirred uniformly, and then polytetrahydrofuran ether diol-2000 and polytetrahydrofuran ether diol-1000 were added, and incubated for 2 h to obtain a polyurethane prepolymer;

[0038] S2: 8 parts of polyether polyol N330, 4 parts of the chain extender, 0.01 parts of dibutyltin dilaurate, 0.5 parts of silicone oil, 0.6 parts of defoaming agent, 0.4 parts of antioxidant and 0.2 parts of ultraviolet absorber were stirred uniformly, vacuum degassed, added into the polyurethane prepolymer, stirred uniformly, poured into a mold, and cured and formed at 80 DEG C and 60 to obtain the polyurethane transparent elastomer.

[0039] In the chain extender, the mass ratio of the organosilicon chain extender, the POSS polyol chain extender and 1,4-butanediol is 4:1:1.

[0040] Embodiment 2: A method for preparing a polyurethane transparent elastomer, comprising the following steps: S1: 10 parts of polytetrahydrofuran ether diol-2000 and 14 parts of polytetrahydrofuran ether diol-1000 are heated to 120 DEG C for vacuum dehydration for 1 h, and then cooled to 65 DEG C for standby; a reaction container is preheated to 70 DEG C, 20 parts of isophorone diisocyanate and 0.2 parts of benzoyl chloride are added, heated to 80 DEG C, stirred uniformly, and then polytetrahydrofuran ether diol-2000 and polytetrahydrofuran ether diol-1000 are added, and reacted for 2 h to obtain a polyurethane prepolymer;

[0041] S2: 8 parts of polyether polyol N330, 4 parts of a chain extender, 0.01 parts of dibutyltin dilaurate, 0.5 parts of silicone oil, 0.6 parts of a defoaming agent, 0.4 parts of an antioxidant, and 0.2 parts of an ultraviolet absorber are stirred uniformly, vacuum degassed, added into the polyurethane prepolymer, stirred uniformly, poured into a mold, and then cured and formed at 80 DEG C for 60 min to obtain a polyurethane transparent elastomer.

[0042] The mass ratio of the organic silicon chain extender, the POSS polyol chain extender, and 1,4-butanediol in the chain extender is 3:2:1.

[0043] Embodiment 3: A method for preparing a polyurethane transparent elastomer, comprising the following steps: S1: 10 parts of polytetrahydrofuran ether diol-2000 and 14 parts of polytetrahydrofuran ether diol-1000 are heated to 120 DEG C for vacuum dehydration for 1 h, and then cooled to 65 DEG C for standby; a reaction container is preheated to 70 DEG C, 20 parts of isophorone diisocyanate and 0.2 parts of benzoyl chloride are added, heated to 80 DEG C, stirred uniformly, and then polytetrahydrofuran ether diol-2000 and polytetrahydrofuran ether diol-1000 are added, and reacted for 2 h to obtain a polyurethane prepolymer;

[0044] S2: 8 parts of polyether polyol N330, 4 parts of a chain extender, 0.01 parts of dibutyltin dilaurate, 0.5 parts of silicone oil, 0.6 parts of a defoaming agent, 0.4 parts of an antioxidant, and 0.2 parts of an ultraviolet absorber are stirred uniformly, vacuum degassed, added into the polyurethane prepolymer, stirred uniformly, poured into a mold, and then cured and formed at 80 DEG C for 60 min to obtain a polyurethane transparent elastomer.

[0045] The mass ratio of the organic silicon chain extender, the POSS polyol chain extender, and 1,4-butanediol in the chain extender is 2:3:1.

[0046] Embodiment 4: A method for preparing a polyurethane transparent elastomer, comprising the following steps: S1: 10 parts of polytetrahydrofuran ether diol-2000, 14 parts of polytetrahydrofuran ether diol-1000 are heated to 120°C and vacuum dehydrated for 1h, cooled to 65°C, and standby; the reaction container is preheated to 70°C, 20 parts of isophorone diisocyanate, 0.2 parts of benzoyl chloride are added, heated to 80°C, stirred uniformly, and then polytetrahydrofuran ether diol-2000 and polytetrahydrofuran ether diol-1000 are added, and incubated for 2h to obtain a polyurethane prepolymer;

[0047] S2: 8 parts of polyether polyol N330, 6 parts of chain extender, 0.01 parts of dibutyltin dilaurate, 0.5 parts of silicone oil, 0.6 parts of defoaming agent, 0.4 parts of antioxidant and 0.2 parts of ultraviolet absorber are stirred uniformly, vacuum degassed, added into the polyurethane prepolymer, stirred uniformly, poured into a mold, 80°C, 60 solidified and formed, demolded, and a polyurethane transparent elastomer was obtained.

[0048] The mass ratio of the chain extender, the organosilicon chain extender, the POSS polyol chain extender and the 1,4-butanediol is 3:2:1.

[0049] Embodiment 5: A method for preparing a polyurethane transparent elastomer, comprising the following steps: S1: 10 parts of polytetrahydrofuran ether diol-2000, 14 parts of polytetrahydrofuran ether diol-1000 are heated to 120°C and vacuum dehydrated for 1h, cooled to 65°C, and standby; the reaction container is preheated to 70°C, 20 parts of isophorone diisocyanate, 0.2 parts of benzoyl chloride are added, heated to 80°C, stirred uniformly, and then polytetrahydrofuran ether diol-2000 and polytetrahydrofuran ether diol-1000 are added, and incubated for 2h to obtain a polyurethane prepolymer;

[0050] S2: 8 parts of polyether polyol N330, 6 parts of chain extender, 0.01 parts of dibutyltin dilaurate, 0.5 parts of silicone oil, 0.6 parts of defoaming agent, 0.4 parts of antioxidant and 0.2 parts of ultraviolet absorber are stirred uniformly, vacuum degassed, added into the polyurethane prepolymer, stirred uniformly, poured into a mold, 80°C, 60 solidified and formed, demolded, and a polyurethane transparent elastomer was obtained.

[0051] The mass ratio of the chain extender, the organosilicon chain extender, the POSS polyol chain extender and the 1,4-butanediol is 3:2:1.

[0052] Preparation method of a polyurethane transparent elastomer, comprising the following steps: S1: 10 parts of polytetrahydrofuran ether diol-2000, 14 parts of polytetrahydrofuran ether diol-1000 are heated to 120°C and vacuum dehydrated for 1h, cooled to 65°C, and prepared for use; the reaction vessel is preheated to 70°C, 20 parts of isophorone diisocyanate, 0.2 parts of benzoyl chloride are added, heated to 80°C, stirred uniformly, and polytetrahydrofuran ether diol-2000, polytetrahydrofuran ether diol-1000 are added, and reacted for 2h to obtain a polyurethane prepolymer;

[0053] S2: 3 mol of octamethylcyclotetrasiloxane, 3 mol of hexamethyldisiloxane, and triflic acid are added to deionized water, heated to 80°C and reacted for 5h, cooled to room temperature, the product is washed with 75wt% ethanol, and vacuum distilled at 75°C and -0.1MPa to obtain a silicone segment;

[0054] S2: 8 parts of polyether polyol N330, 2.6 parts of the silicone segment, 1.4 parts of the chain extender, 0.01 parts of dibutyltin dilaurate, 0.5 parts of silicone oil, 0.6 parts of defoaming agent, 0.4 parts of antioxidant, and 0.2 parts of ultraviolet absorber are stirred uniformly, vacuum degassed, added to the polyurethane prepolymer, stirred uniformly, poured into a mold, and cured and formed at 80°C and 60 to obtain a polyurethane transparent elastomer.

[0055] In the chain extender, the mass ratio of the POSS polyol chain extender and 1,4-butanediol is 1:1.

[0056] Preparation method of a polyurethane transparent elastomer, comprising the following steps: S1: 10 parts of polytetrahydrofuran ether diol-2000, 14 parts of polytetrahydrofuran ether diol-1000 are heated to 120°C and vacuum dehydrated for 1h, cooled to 65°C, and prepared for use; the reaction vessel is preheated to 70°C, 20 parts of isophorone diisocyanate, 0.2 parts of benzoyl chloride are added, heated to 80°C, stirred uniformly, and polytetrahydrofuran ether diol-2000, polytetrahydrofuran ether diol-1000 are added, and reacted for 2h to obtain a polyurethane prepolymer;

[0057] S2: 8 parts of polyether polyol N330, 0.7 parts of chloropropyl POSS, 3.3 parts of the chain extender, 0.01 parts of dibutyltin dilaurate, 0.5 parts of silicone oil, 0.6 parts of defoaming agent, 0.4 parts of antioxidant, and 0.2 parts of ultraviolet absorber are stirred uniformly, vacuum degassed, added to the polyurethane prepolymer, stirred uniformly, poured into a mold, and cured and formed at 80°C and 60 to obtain a polyurethane transparent elastomer.

[0058] In the chain extender, the mass ratio of the silicone chain extender and 1,4-butanediol is 4:1.

[0059] Comparative Example 3: A method for preparing a polyurethane transparent elastomer, comprising the following steps: S1: 10 parts of polytetrahydrofuran ether diol-2000, 14 parts of polytetrahydrofuran ether diol-1000 are heated to 120°C and vacuum dehydrated for 1h, cooled to 65°C, and reserved; the reaction vessel is preheated to 70°C, 20 parts of isophorone diisocyanate, 0.2 parts of benzoyl chloride are added, heated to 80°C, stirred uniformly, and then polytetrahydrofuran ether diol-2000 and polytetrahydrofuran ether diol-1000 are added, and incubated for 2h to obtain a polyurethane prepolymer;

[0060] S2: 8 parts of polyether polyol N330, 4 parts of chain extender, 0.01 parts of dibutyltin dilaurate, 0.5 parts of silicone oil, 0.6 parts of defoaming agent, 0.4 parts of antioxidant, and 0.2 parts of ultraviolet absorber are stirred uniformly, vacuum degassed, added into the polyurethane prepolymer, stirred uniformly, poured into a mold, and cured at 80°C for 60min to form, demolded to obtain a polyurethane transparent elastomer.

[0061] The mass ratio of the organic silicon chain extender, the POSS polyol chain extender, and 1,4-butanediol in the chain extender is 5:1:1.

[0062] Comparative Example 4: A method for preparing a polyurethane transparent elastomer, comprising the following steps: S1: 10 parts of polytetrahydrofuran ether diol-2000, 14 parts of polytetrahydrofuran ether diol-1000 are heated to 120°C and vacuum dehydrated for 1h, cooled to 65°C, and reserved; the reaction vessel is preheated to 70°C, 20 parts of isophorone diisocyanate, 0.2 parts of benzoyl chloride are added, heated to 80°C, stirred uniformly, and then polytetrahydrofuran ether diol-2000 and polytetrahydrofuran ether diol-1000 are added, and incubated for 2h to obtain a polyurethane prepolymer;

[0063] S2: 8 parts of polyether polyol N330, 4 parts of chain extender, 0.01 parts of dibutyltin dilaurate, 0.5 parts of silicone oil, 0.6 parts of defoaming agent, 0.4 parts of antioxidant, and 0.2 parts of ultraviolet absorber are stirred uniformly, vacuum degassed, added into the polyurethane prepolymer, stirred uniformly, poured into a mold, and cured at 80°C for 60min to form, demolded to obtain a polyurethane transparent elastomer.

[0064] The mass ratio of the organic silicon chain extender, the POSS polyol chain extender, and 1,4-butanediol in the chain extender is 2:4:1.

[0065] Experiment: The mechanical properties of the elastomers prepared in the above examples and comparative examples are tested according to GB / T 528-2009;

[0066] The abrasion performance of the elastomers prepared in the above examples and comparative examples is tested according to GB / T 9867-2008.

[0067] The elastomers prepared in the above examples and comparative examples were tested for yellowing resistance according to ASTM-D1148.

[0068] The experimental results are shown in Table 1 below.

[0069] Table 1: Test performance table of polyurethane transparent elastomer experiment

[0070]

[0071] Conclusion: The polyurethane elastomer prepared by the application has excellent mechanical properties, wear resistance and yellowing resistance.

[0072] In Comparative Example 1, the direct introduction of the silicone segment, and in Comparative Example 2, the direct introduction of the POSS filler, both result in reduced compatibility with the polyurethane matrix, resulting in reduced performance.

[0073] In Comparative Example 3, the content of the silicone chain extender is too large, and in Comparative Example 4, the content of the POSS chain extender is too large, which destroys the balance between the flexible segment and the rigid segment, loses the synergistic effect, and at the same time, the excessive amount of addition also leads to reduced compatibility, resulting in reduced performance.

[0074] It is apparent to those skilled in the art that the application is not limited to the details of the foregoing exemplary embodiments, and that the application can be implemented in other specific forms without departing from the spirit or essential characteristics of the application. Therefore, the embodiments should be considered in all respects as illustrative and not restrictive, and the scope of the application should be defined by the appended claims rather than the above description, and it is intended to include all changes falling within the meaning and scope of the equivalent elements of the claims.

Claims

1. A process for the preparation of a polyurethane transparent elastomer, characterized in that: It comprises the following steps: S1: polytetrahydrofuran ether glycol-2000, polytetrahydrofuran ether glycol-1000 is heated to 120-130℃ vacuum dehydration 1-2h, cooling to 65-75℃, standby; The reaction vessel is preheated to 70-75℃, and isophorone diisocyanate, benzoyl chloride is added, heated to 80-90℃, stirred uniformly, polytetrahydrofuran ether glycol-2000, polytetrahydrofuran ether glycol-1000 is added, and the reaction is kept for 2-3h to obtain polyurethane prepolymer; S2: polyether polyol N330, chain extender, dibutyltin dilaurate, silicone oil, defoamer, antioxidant and ultraviolet absorber are stirred uniformly, vacuum degassed, added into the polyurethane prepolymer, stirred uniformly, poured into the mold, cured and formed, demolded, and the polyurethane transparent elastomer is obtained; The chain extender comprises organosilicon chain extender, POSS polyol chain extender and 1,4-butanediol. The preparation method of the organosilicon chain extender comprises the following steps: adding ethanolamine intermediate, octamethylcyclotetrasiloxane, hexamethyldisiloxane and triflic acid into deionized water, heating to 80-85℃ for 5-5.5h, cooling to room temperature, washing, vacuum distillation, and obtaining the organosilicon chain extender. The preparation method of the ethanolamine intermediate comprises the following steps: adding ethanolamine into N,N-dimethylformamide, stirring uniformly, adding vanillin organosilicon monomer, heating to 70-75℃ for 5-5.5h, vacuum filtering, drying, grinding, and obtaining the ethanolamine intermediate. The preparation method of the vanillin organosilicon monomer comprises the following steps: adding KH550 into chloroform, adding polyformaldehyde, stirring uniformly, adding vanillin trichloromethanol solution, heating to reflux for 36-38h, cooling to room temperature, filtering, washing, drying, filtering, rotary evaporation, vacuum drying at 70-75℃ for 2-2.5h, and obtaining the vanillin organosilicon monomer. The POSS polyol chain extender is prepared by polyaldehyde modified POSS redox. The polyaldehyde modified POSS is prepared by vanillin grafted modified chloropropyl POSS.

2. The process for the preparation of a polyurethane transparent elastomer according to claim 1, characterized in that: The mass ratio of each component in the polyurethane transparent elastomer comprises, by mass fraction: polytetrahydrofuran ether glycol-2000 10-16 parts, polytetrahydrofuran ether glycol-1000 14-16 parts, isophorone diisocyanate 20-24 parts, benzoyl chloride 0.2-0.3 parts, polyether polyol N330 8-12 parts, chain extender 4-8 parts, dibutyltin dilaurate 0.01-0.02 parts, silicone oil 0.5-1 part, defoamer 0.6-1.2 parts, antioxidant 0.4-0.8 parts and ultraviolet absorber 0.2-0.6 parts.

3. The process for the preparation of a polyurethane transparent elastomer according to claim 1, characterized in that: In the chain extender, the mass ratio of organosilicon chain extender, POSS polyol chain extender and 1,4-butanediol is (2-4):(1-3):

1.

4. The process for the preparation of a polyurethane transparent elastomer according to claim 1, characterized in that: In the preparation process of the organosilicon chain extender, the molar ratio of ethanolamine intermediate: octamethylcyclotetrasiloxane: hexamethyldisiloxane is 1:(2-5):(3-5).

5. The process for the preparation of a polyurethane transparent elastomer according to claim 1, characterized in that: The molar ratio of ethanolamine: vanillin organosilicon monomer is (2-3):1 in the preparation process of the ethanolamine intermediate.

6. The process for the preparation of a polyurethane transparent elastomer according to claim 1, characterized in that: The molar ratio of KH550: paraformaldehyde: vanillin is 1:5:1 in the preparation process of the vanillin organosilicon monomer.

7. The process for the preparation of a polyurethane transparent elastomer according to claim 1, characterized in that: The preparation method of the POSS polyol chain extender comprises the following steps: adding polyaldehyde modified POSS and hydroxylamine hydrochloride into pyridine, heating to 115-120 DEG C to reflux for 3-3.5 h, cooling to room temperature, pouring the mixture into deionized water, filtering, washing, vacuum drying at 60-65 DEG C, and obtaining the POSS polyol chain extender. The mass ratio of polyaldehyde modified POSS: hydroxylamine hydrochloride is 5:(2-3) in the preparation process of the POSS polyol chain extender.

8. The process for the preparation of a polyurethane transparent elastomer according to claim 7, characterized in that: The preparation method of the polyaldehyde modified POSS comprises the following steps: adding vanillin and potassium carbonate into tetrahydrofuran, stirring uniformly, adding chloropropyl POSS tetrahydrofuran solution, heating to 80-85 DEG C to reflux for 2-2.5 h, pouring the mixture into deionized water, filtering, washing the product to neutral, vacuum drying at 70-75 DEG C, and obtaining the polyaldehyde modified POSS. The molar ratio of vanillin: potassium carbonate: chloropropyl POSS is (8-9):(8-9):1 in the preparation process of the polyaldehyde modified POSS.

9. The polyurethane transparent elastomer prepared by the preparation method of the polyurethane transparent elastomer according to any one of claims 1-8.

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