High-temperature-resistant polyurethane elastomer material and preparation process thereof

Abstract

The invention relates to the technical field of polyurethane elastomers, and discloses a high-temperature-resistant polyurethane elastomer material and a preparation process thereof, 2, 4, 6-tri-(nitronaphthalene-phenyl)-[1, 3, 5] triazine obtained by reaction of 2, 4, 6-tri-(4-bromophenyl)-[1, 3, 5] triazine and 4-nitro-1-naphthol has excellent heat resistance; the aromatic naphthalene ring structure has a rigid structure, the molecular chain of the aromatic naphthalene ring structure is highly regular, and the polyurethane elastomer synthesized by the aromatic naphthalene ring structure has excellent dynamic performance; 2, 4, 6-tri-(aminonaphthalene-phenyl)-[1, 3, 5] triazine after reduction is utilized to prepare a chain extender containing diamine, and the chain extender and isocyanate generate carbamido, so that the tensile strength of the polyurethane elastomer is improved; through the synergistic effect of triazine, naphthalene ring and hydrogen bond, the prepared polyurethane elastomer is excellent in mechanical property and obvious in high temperature resistance advantage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of polyurethane elastomer, in particular to a high-temperature-resistant polyurethane elastomer material and preparation process. BACKGROUND

[0002] Polyurethane elastomer is a special material with performance between plastic and rubber, which has high strength, wear resistance and tear resistance, and has achieved ideal effect in various fields. However, due to the low thermal decomposition temperature and poor heat resistance of polyurethane elastomer, especially in the environment with high temperature, the mechanical property retention rate is low, which greatly limits its application range. With the increasing demand for material performance, many domestic and foreign experts and scholars have conducted in-depth research on how to improve the heat resistance of polyurethane elastomer.

[0003] The main chain of polyurethane elastomer is a block polymer composed of flexible soft segment and rigid hard segment. The soft segment providing elasticity and toughness is composed of polyol, and the hard segment providing hardness and modulus is composed of isocyanate and chain extender. The invention patent CN104448197B discloses a synthesis method of heat-resistant polyurethane elastomer, which is prepared by reaction of polyester polyol, diisocyanate and MOCA or butanediol as chain extender. The obtained elastomer has high performance retention rate at high temperature and is suitable for places with high environmental temperature. However, the soft segment content in polyurethane elastomer is high, and the mechanical property is poor. In the present application, the chain extender in the modified polyurethane elastomer is improved, the heat resistance of the polyurethane material is improved by using the high thermal decomposition temperature of triazine structure, and the mechanical property of the polyurethane material is improved by using the highly regular molecular structure of naphthalene ring. The combination of the two makes the prepared polyurethane elastomer crosslinked into a network structure, which increases the high-temperature resistance and mechanical strength while maintaining the elastic toughness like rubber. SUMMARY

[0004] The technical problem solved by the present application is to provide a high-temperature-resistant polyurethane elastomer material and preparation process, which solves the problem of poor heat resistance of polyurethane elastomer material.

[0005] The technical scheme of the present application is: A high-temperature-resistant polyurethane elastomer material and preparation process, the preparation process is carried out according to the following steps: Step S1, 2,4,6-tri-(4-bromophenyl)-[1,3,5] triazine and N'N-dimethylformamide are added to a reaction bottle equipped with a condenser tube and a thermometer, stirred uniformly, 4-nitro-1-naphthol and potassium carbonate are added, after reaction, cooling and filtration, the filtrate is precipitated by adding methanol, filtered, washed with deionized water and methanol, and dried to obtain 2,4,6-tri-(nitro naphthalene-phenyl)-[1,3,5] triazine. The preparation reaction formula is as follows:

[0006] Step S2, zinc powder and 2,4,6-tri-(nitro naphthalene-phenyl)-[1,3,5] triazine are added into the solvent of ethanol and deionized water in sequence, stirred uniformly, 27% hydrochloric acid is added dropwise at 0-10°C, after the reaction is completed, filtration is carried out, the filtrate is extracted with chloroform, the organic phase is concentrated and dried, and acetone is used for washing, so that 2,4,6-tri-(amino naphthalene-phenyl)-[1,3,5] triazine is obtained. The preparation reaction formula is as follows:

[0007] Step S3, 100 parts of polycaprolactone polyol by weight is added into a reaction bottle, after stirring under a nitrogen atmosphere, 40-55 parts of 4,4-diphenyl methane diisocyanate is added, after the reaction is completed, vacuum degassing is carried out for 30-40 min, and an isocyanate-terminated polyurethane prepolymer is obtained.

[0008] Step S4, 2,4,6-tri-(amino naphthalene-phenyl)-[1,3,5] triazine is dissolved in tetrahydrofuran and added into the isocyanate-terminated polyurethane prepolymer, stirred for 10-20 min, after vacuum degassing, poured into a mold which is preheated and coated with a release agent, vulcanized at 100-120°C for 12-24 h, and a high-temperature-resistant polyurethane elastomer material is obtained.

[0009] Further, the amount of 4-nitro-1-naphthol and potassium carbonate in step S1 is 110-150% and 35-42% of the amount of 2,4,6-tri-(4-bromophenyl)-[1,3,5] triazine, respectively.

[0010] Further, the reaction temperature in step S1 is 140-160°C, and the reaction time is 16-24 h.

[0011] Further, the amount of zinc powder and 27% hydrochloric acid in step S2 is 70%-110% and 40-70% of the amount of 2,4,6-tri-(nitro naphthalene-phenyl)-[1,3,5] triazine, respectively.

[0012] Further, the reaction temperature in step S2 is 50-70°C, and the reaction time is 3-8 h.

[0013] Further, the reaction temperature in step S3 is 75-85°C, and the reaction time is 2-4 h.

[0014] Further, the amount of 2,4,6-tri-(amino naphthalene-phenyl)-[1,3,5] triazine in step S4 is 36-63% of the amount of the isocyanate-terminated polyurethane prepolymer.

[0015] The beneficial technical effects of the present application are: The present application firstly reacts 2,4,6-tri-(4-bromophenyl)-[1,3,5]triazine with 4-nitro-1-naphthol to obtain 2,4,6-tri-(nitro naphthalene-phenyl)-[1,3,5]triazine, then reduces the nitro group under the action of zinc powder and hydrochloric acid to obtain 2,4,6-tri-(amino naphthalene-phenyl)-[1,3,5]triazine, then obtains an isocyanate-terminated polyurethane prepolymer by vacuum deaeration of polycaprolactone polyol and 4,4-diphenyl methane diisocyanate, and finally obtains a high-temperature-resistant polyurethane elastomer material by pouring and curing after using 2,4,6-tri-(amino naphthalene-phenyl)-[1,3,5]triazine as a chain extender.

[0016] 2,4,6-tri-(4-bromophenyl)-[1,3,5]triazine reacts with 4-nitro-1-naphthol to obtain 2,4,6-tri-(nitro naphthalene-phenyl)-[1,3,5]triazine, which contains both triazine and naphthalene ring structures, the triazine ring structure is stable and not easy to decompose at high temperature, and has excellent heat resistance, and when introduced into a polyurethane elastomer, the heat resistance of the polyurethane material is increased; the aromatic naphthalene ring structure has a rigid symmetrical structure, and the molecular chain is highly regular, and the polyurethane elastomer synthesized therefrom has excellent dynamic performance, and has the advantages of good elasticity and high-temperature resistance; 2,4,6-tri-(nitro naphthalene-phenyl)-[1,3,5]triazine is reduced to 2,4,6-tri-(amino naphthalene-phenyl)-[1,3,5]triazine, a chain extender containing diamine is prepared, the chain extender can form a urea group with isocyanate, contains two active hydrogens to form hydrogen bonds, the relative density of the hydrogen bonds is high, the intermolecular interaction is strong, and the thermal decomposition temperature is high, so the effect of the hydrogen bonds improves the tensile strength of the polyurethane elastomer; the synergistic effect of the triazine, naphthalene ring and hydrogen bond makes the prepared polyurethane elastomer not only have excellent mechanical properties, but also have the advantage of high-temperature resistance. DETAILED DESCRIPTION

[0017] The above content of the present application is further described in detail through the following examples, but this should not be understood as limiting the scope of the above subject matter of the present application to only the following examples, and any technology realized based on the above content of the present application belongs to the scope of the present application.

[0018] Example 1 Step S1, 50g of 2,4,6-tri-(4-bromophenyl)-[1,3,5]triazine and N’N-dimethylformamide were added to a reaction bottle equipped with a condenser and a thermometer, stirred uniformly, 70g of 4-nitro-1-naphthol and 20g of potassium carbonate were added, and after reaction at 150℃ for 18h, it was cooled and filtered, the filtrate was precipitated by adding methanol, filtered, washed with deionized water and methanol, and dried to obtain 2,4,6-tri-(nitro naphthalene-phenyl)-[1,3,5]triazine.

[0019] Step S2, 20 g of zinc powder and 25 g of 2,4,6-tris-(nitro naphthalene-phenyl)-[1,3,5]triazine were sequentially added to a solvent of ethanol and deionized water, stirred uniformly, 15 g of 27% hydrochloric acid was added dropwise at 0°C, after reaction at 70°C for 4 h, filtration, the filtrate was extracted with chloroform, the organic phase was concentrated and dried, washed with acetone, to obtain 2,4,6-tris-(amino naphthalene-phenyl)-[1,3,5]triazine.

[0020] Step S3, 60 g of polycaprolactone polyol was added to the reaction bottle, after stirring under nitrogen atmosphere, 30 g of 4,4-diphenyl methane diisocyanate was added, after reaction at 80°C for 4 h, vacuum degassing for 30 min, to obtain an isocyanate-terminated polyurethane prepolymer.

[0021] Step S4, 36 g of 2,4,6-tris-(amino naphthalene-phenyl)-[1,3,5]triazine was dissolved in tetrahydrofuran and added to 100 g of isocyanate-terminated polyurethane prepolymer, stirred for 20 min, vacuum degassed and poured into a preheated and release agent coated mold, after curing at 110°C for 16 h, a high temperature resistant polyurethane elastomer material was obtained.

[0022] Example 2 Step S1, 30 g of 2,4,6-tris-(4-bromophenyl)-[1,3,5]triazine and N'N-dimethylformamide were added to a reaction bottle equipped with a condenser and a thermometer, stirred uniformly, 40 g of 4-nitro-1-naphthol and 11 g of potassium carbonate were added, after reaction at 140°C for 24 h, cooled and filtered, the filtrate was precipitated by adding methanol, filtered, washed with deionized water and methanol, and dried to obtain 2,4,6-tris-(nitro naphthalene-phenyl)-[1,3,5]triazine.

[0023] Step S2, 24 g of zinc powder and 40 g of 2,4,6-tris-(nitro naphthalene-phenyl)-[1,3,5]triazine were sequentially added to a solvent of ethanol and deionized water, stirred uniformly, 20 g of 27% hydrochloric acid was added dropwise at 5°C, after reaction at 70°C for 5 h, filtration, the filtrate was extracted with chloroform, the organic phase was concentrated and dried, washed with acetone, to obtain 2,4,6-tris-(amino naphthalene-phenyl)-[1,3,5]triazine.

[0024] Step S3, 200 g of polycaprolactone polyol was added to the reaction bottle, after stirring under nitrogen atmosphere, 90 g of 4,4-diphenyl methane diisocyanate was added, after reaction at 75°C for 4 h, vacuum degassing for 40 min, to obtain an isocyanate-terminated polyurethane prepolymer.

[0025] Step S4, 43g of 2,4,6-tris-(amino naphthalene-phenyl)-[1,3,5]triazine was dissolved in tetrahydrofuran, added to 100g of isocyanate-terminated polyurethane prepolymer, stirred for 20min, vacuum degassing, poured into a preheated and coated with release agent mold, vulcanized at 120℃ for 14h, to obtain high temperature resistant polyurethane elastomer material.

[0026] Example 3 Step S1, to the reaction bottle equipped with condenser and thermometer, 100g of 2,4,6-tris-(4-bromophenyl)-[1,3,5]triazine and N'N-dimethylformamide were added, stirred uniformly, 110g of 4-nitro-1-naphthol and 42g of potassium carbonate were added, reacted at 160℃ for 22h, cooled and filtered, the filtrate was precipitated by adding methanol, filtered, washed with deionized water and methanol, dried to obtain 2,4,6-tris-(nitro naphthalene-phenyl)-[1,3,5]triazine.

[0027] Step S2, 96g of zinc powder and 120g of 2,4,6-tris-(nitro naphthalene-phenyl)-[1,3,5]triazine were added in sequence to the solvent of ethanol and deionized water, stirred uniformly, 72g of 27% hydrochloric acid was added dropwise at 10℃, reacted at 50℃ for 6h, filtered, the filtrate was extracted with chloroform, the organic phase was concentrated and dried, washed with acetone to obtain 2,4,6-tris-(amino naphthalene-phenyl)-[1,3,5]triazine.

[0028] Step S3, 150g of polycaprolactone polyol was added to the reaction bottle, stirred under nitrogen atmosphere, 75g of 4,4-diphenyl methane diisocyanate was added, reacted at 85℃ for 4h, vacuum degassing for 35min to obtain isocyanate-terminated polyurethane prepolymer.

[0029] Step S4, 50g of 2,4,6-tris-(amino naphthalene-phenyl)-[1,3,5]triazine was dissolved in tetrahydrofuran, added to 100g of isocyanate-terminated polyurethane prepolymer, stirred for 15min, vacuum degassing, poured into a preheated and coated with release agent mold, vulcanized at 100℃ for 20h, to obtain high temperature resistant polyurethane elastomer material.

[0030] Example 4 Step S1, to the reaction bottle equipped with condenser and thermometer, 40g of 2,4,6-tris-(4-bromophenyl)-[1,3,5]triazine and N'N-dimethylformamide were added, stirred uniformly, 60g of 4-nitro-1-naphthol and 16g of potassium carbonate were added, reacted at 150℃ for 24h, cooled and filtered, the filtrate was precipitated by adding methanol, filtered, washed with deionized water and methanol, dried to obtain 2,4,6-tris-(nitro naphthalene-phenyl)-[1,3,5]triazine.

[0031] Step S2, 110 g of zinc powder and 100 g of 2,4,6-tris-(nitro naphthalene- phenyl)-[1,3,5]triazine were added in sequence to a solvent of ethanol and deionized water, stirred uniformly, 65 g of 27% hydrochloric acid was added dropwise at 0°C, after reaction for 8 h at 70°C, filtered, the filtrate was extracted with chloroform, the organic phase was concentrated and dried, washed with acetone, to obtain 2,4,6-tris-(amino naphthalene-phenyl)-[1,3,5]triazine.

[0032] Step S3, 50 g of polycaprolactone polyol was added to a reaction bottle, after stirring under nitrogen atmosphere, 26 g of 4,4-diphenyl methane diisocyanate was added, after reaction for 3 h at 80°C, vacuum degassing for 40 min, to obtain an isocyanate-terminated polyurethane prepolymer.

[0033] Step S4, 58 g of 2,4,6-tris-(amino naphthalene-phenyl)-[1,3,5]triazine was dissolved in tetrahydrofuran and added to 100 g of isocyanate-terminated polyurethane prepolymer, stirred for 15 min, vacuum degassed and poured into a preheated and release agent coated mold, after vulcanization for 18 h at 120°C, a high temperature resistant polyurethane elastomer material was obtained.

[0034] Example 5 Step S1, 10 g of 2,4,6-tris-(4-bromophenyl)-[1,3,5]triazine and N’N- dimethylformamide were added to a reaction bottle equipped with a condenser and a thermometer, stirred uniformly, 14 g of 4-nitro-1-naphthol and 4 g of potassium carbonate were added, after reaction for 16 h at 150°C, cooled and filtered, the filtrate was precipitated by adding methanol, filtered, washed with deionized water and methanol, and dried to obtain 2,4,6-tris-(nitro naphthalene-phenyl)-[1,3,5]triazine.

[0035] Step S2, 55 g of zinc powder and 60 g of 2,4,6-tris-(nitro naphthalene- phenyl)-[1,3,5]triazine were added in sequence to a solvent of ethanol and deionized water, stirred uniformly, 28 g of 27% hydrochloric acid was added dropwise at 5°C, after reaction for 5 h at 60°C, filtered, the filtrate was extracted with chloroform, the organic phase was concentrated and dried, washed with acetone, to obtain 2,4,6-tris-(amino naphthalene-phenyl)-[1,3,5]triazine.

[0036] Step S3, 90 g of polycaprolactone polyol was added to a reaction bottle, after stirring under nitrogen atmosphere, 36 g of 4,4-diphenyl methane diisocyanate was added, after reaction for 4 h at 75°C, vacuum degassing for 40 min, to obtain an isocyanate-terminated polyurethane prepolymer.

[0037] Step S4, 63 g of 2,4,6-tris-(amino naphthalene-phenyl)-[1,3,5]triazine was dissolved in tetrahydrofuran, added to 100 g of isocyanate-terminated polyurethane prepolymer, stirred for 20 min, vacuum degassed, and then poured into a preheated mold coated with a release agent, vulcanized at 120°C for 18 h to obtain a high-temperature-resistant polyurethane elastomer material.

[0038] Comparative Example 1 Step S1, 100 g of polycaprolactone polyol was added to a reaction bottle, stirred under a nitrogen atmosphere, 55 g of 4,4-diphenyl methane diisocyanate was added, reacted at 85°C for 4 h, vacuum degassed for 40 min to obtain an isocyanate-terminated polyurethane prepolymer.

[0039] Step S2, 63 g of ethylenediamine was dissolved in tetrahydrofuran, added to 100 g of isocyanate-terminated polyurethane prepolymer, stirred for 20 min, vacuum degassed, and then poured into a preheated mold coated with a release agent, vulcanized at 120°C for 20 h to obtain a high-temperature-resistant polyurethane elastomer material.

[0040] Thermogravimetric test: Thermogravimetric analyzer was used for testing, nitrogen atmosphere, heating rate 10°C / min, sample size 20-30 mg, temperature range 50-600°C.

[0041] T 50% : 50% weight loss temperature, T max : maximum weight loss temperature.

[0042]

[0043] From the above table, with the increase of the content of triazine and naphthalene ring in the polyurethane elastomer, the heat resistance of the polyurethane elastomer material is enhanced, because of the particularity of the structure of triazine and naphthalene ring, triazine ring has high decomposition temperature, aromatic naphthalene ring has large steric hindrance, molecular chain is highly regular, the combination of the two can hinder the relative movement of molecular chain segments during heating process, forming a very stable and rigid system, so that the polymer can absorb a large amount of heat energy without breaking the main chain, and has excellent thermal stability, compared with the polyurethane elastomer without triazine and naphthalene ring in comparative example 1, the 50% weight loss temperature is increased by 39°C, and the maximum weight loss temperature is increased by 40°C, so the introduction of triazine and naphthalene ring improves the thermal stability of the elastomer and enhances the high temperature resistance.

[0044] Mechanical property test: The tensile properties of the elastomer were tested using a universal testing machine, the sample size was 20 mm x 10 mm x 10 mm, and the tensile rate was 200 mm / min.

[0045] Hardness test: tested using a hardness tester.

[0046]

[0047] From the above table, it can be seen that, when other components are the same, the mechanical properties of the polyurethane elastomer with the chain extender 2,4,6-tris-(aminonaphthalene-phenyl)-[1,3,5] triazine are better than those of the elastomer with the chain extender ethylenediamine in Comparative Example 1, with the increase of the content of triazine and naphthalene ring, the strength and hardness of the polyurethane elastomer are increasing, but the elongation at break is decreasing, because the polyurethane elastomer containing triazine and naphthalene ring has a relatively regular structure and a high crystallinity, with the increase of the content of hard segment, the physical crosslinking points in the molecular chain segment are increasing, so that the breaking strength and hardness are increasing with the increase of the content of hard segment; at the same time, the increase of the content of hard segment makes the soft segment motion molecular chain shorter, resulting in the molecular motion being blocked, so that the elongation at break of the material is reduced, but the whole system still has high elasticity, keeping the characteristics of the elastomer.

[0048] The above description is only the preferred specific implementation of the present application, but the protection scope of the present application is not limited to this, any skilled person in the art can make equivalent replacement or change according to the technical solution and the inventive concept of the present application within the technical range disclosed by the present application, which should be covered in the protection scope of the present application.

Claims

1. A process for the preparation of a high temperature resistant polyurethane elastomer material, characterized in that: The preparation process is carried out in the following steps: Step S1, 2, 4, 6-tri-(4-bromophenyl)-[1, 3, 5] triazine and N'N-dimethylformamide are added to the reaction bottle equipped with a condenser and a thermometer, stirred uniformly, 4-nitro-1-naphthol and potassium carbonate are added, after the reaction is completed, cooling and filtration, the filtrate is precipitated with methanol, filtered, washed with deionized water and methanol, dried to obtain 2, 4, 6-tri-(nitro naphthalene-phenyl)-[1, 3, 5] triazine; Step S2, zinc powder and 2, 4, 6-tri-(nitro naphthalene-phenyl)-[1, 3, 5] triazine are added to the solvent of ethanol and deionized water in turn, stirred uniformly, 27% hydrochloric acid is added dropwise at 0-10℃, after the reaction is completed, filtration, the filtrate is extracted with chloroform, the organic phase is concentrated and dried, washed with acetone to obtain 2, 4, 6-tri-(amino naphthalene-phenyl)-[1, 3, 5] triazine; Step S3, 100 parts of polycaprolactone polyol are added to the reaction bottle, stirred under nitrogen atmosphere, then 40-55 parts of 4, 4-diphenyl methane diisocyanate are added, after the reaction is completed, vacuum degassing for 30-40min to obtain an isocyanate-terminated polyurethane prepolymer; Step S4, 2, 4, 6-tri-(amino naphthalene-phenyl)-[1, 3, 5] triazine is dissolved in tetrahydrofuran and added to the isocyanate-terminated polyurethane prepolymer, stirred for 10-20min, vacuum degassed, then poured into a preheated mold coated with a release agent, vulcanized at 100-120℃ for 12-24h to obtain a high-temperature-resistant polyurethane elastomer material.

2. The process for the preparation of high temperature resistant polyurethane elastomeric material as claimed in claim 1, wherein: The amount of 4-nitro-1-naphthol and potassium carbonate in step S1 is 110-150% and 35-42% of the amount of 2, 4, 6-tri-(4-bromophenyl)-[1, 3, 5] triazine, respectively.

3. The process for the preparation of high temperature resistant polyurethane elastomeric material as claimed in claim 1, wherein: The reaction temperature in step S1 is 140-160℃, and the reaction time is 16-24h.

4. The process for the production of high temperature resistant polyurethane elastomer material as claimed in claim 1, wherein: The amount of zinc powder and 27% hydrochloric acid in step S2 is 70%-110% and 40-70% of the amount of 2, 4, 6-tri-(nitro naphthalene-phenyl)-[1, 3, 5] triazine, respectively.

5. The process for the preparation of high temperature resistant polyurethane elastomeric material as claimed in claim 1, wherein: The reaction temperature in step S2 is 50-70℃, and the reaction time is 3-8h.

6. The process for the production of high temperature resistant polyurethane elastomer material as claimed in claim 1, wherein: The reaction temperature in step S3 is 75-85℃, and the reaction time is 2-4h.

7. The process for the production of high temperature resistant polyurethane elastomer material as claimed in claim 1 wherein: The amount of 2, 4, 6-tri-(amino naphthalene-phenyl)-[1, 3, 5] triazine in step S4 is 36-63% of the amount of isocyanate-terminated polyurethane prepolymer.

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