Highly grease resistant thermoplastic polyester elastomer composite and method of making

Abstract

This invention discloses a highly grease-resistant thermoplastic polyester elastomer composite material and its preparation method. The composite material is prepared from the following components in parts by weight: 80-95 parts thermoplastic polyester elastomer, 5-20 parts thermoplastic polyamide material, 0.3-2 parts amide composite functional additive, 0.3-2 parts stearic acid additive, 0.5-2 parts chain extender, 0.25-1 part solvent, and 0.6 parts antioxidant; the amide composite functional additive is a composite of oleamide, erucamide, and aliphatic bisamides. The highly grease-resistant thermoplastic polyester elastomer composite material provided by this invention exhibits good performance retention in highly polar grease environments, enabling the protection of drive shafts in the automotive field to function normally under high-temperature environments with grease corrosion, and also offering advantages such as lower noise and longer service life.

Description

Technical Field

[0001] This invention belongs to the field of polymer materials technology, specifically relating to a high oil-resistant thermoplastic polyester elastomer composite material and its preparation method. Background Technology

[0002] Thermoplastic polyester elastomers (TPEEs) are block copolymers containing polyester hard segments and polyether soft segments. TPEEs possess the elasticity of rubber and the strength of engineering plastics. The soft segments give them elasticity, making them rubber-like; the hard segments give them processability, making them plastic-like. Compared to rubber, they have better processability and a longer service life; compared to engineering plastics, they also have high strength, but with better flexibility and dynamic mechanical properties. TPEEs exhibit high strength, high elasticity, oil resistance, acid and alkali resistance, high temperature resistance, radiation resistance, and excellent dynamic mechanical properties. They have a wide operating temperature range of -50℃ to 180℃ and a hardness range of 25D to 80D. Initially, TPEEs were researched and developed for the textile industry to produce highly elastic fibers. However, TPEEs have now become an irreplaceable high-performance new elastomer material, widely used in the automotive, electronics, and railway industries. To meet market demands and broaden application areas, TPEEs need to be modified to develop heat-resistant, flame-retardant, glass fiber reinforced, high-strength, high-transparency, high-oil-resistance, and rubber-textured products. TPEE has good oil resistance to alkane oils and common oils, but it loses its oil resistance to special oils, especially polar oils, under high temperature conditions. Although the patent CN108603017A proposes a solution for oil resistance, it still cannot fully meet the requirements of harsh operating environments. In particular, there is still much room for improvement in oil resistance, and it does not play a role in noise reduction. Summary of the Invention

[0003] To address the shortcomings of existing technologies, the present invention aims to provide a high grease-resistant thermoplastic polyester elastomer composite material and its preparation method. This high grease-resistant thermoplastic polyester elastomer composite material maintains good performance in highly polar grease environments, enabling the protection of drive shafts in the automotive field to function normally under high-temperature environments with grease corrosion, and also has the advantages of lower noise and longer service life.

[0004] The objective of this invention is achieved through the following technical solution:

[0005] A highly oil-resistant thermoplastic polyester elastomer composite material is prepared from the following components in parts by weight:

[0006]

[0007]

[0008] in:

[0009] The thermoplastic polyamide material is at least one of PA6, PA66, PA611, PA612, PA610, PA612, PA1010, PA1012, PA510, PA513, PA516, PA46, and PA612.

[0010] The amide-based composite functional additive is a complex composed of oleamide, erucamide, and aliphatic diamides. The aliphatic diamide is at least one of ethylene bis-stearamide and ethylene bis-oleamide. Further, the weight ratio of oleamide, erucamide, and aliphatic diamide is 3:5:2.

[0011] The stearic acid additive is at least one of stearic acid, zinc stearate, sodium stearate, aluminum distearate, glyceryl monostearate, and dipentaerythritol stearate (PETS).

[0012] The chain extender is at least one of epoxy chain extenders, isocyanate chain extenders, and compounds containing a diamino group. More preferably, the epoxy chain extender is a substance of glycidyl ether type, glycidyl ester type, glycidyl amine type, aliphatic epoxy, or alicyclic epoxy; the isocyanate chain extender is at least one of toluene diisocyanate (TDI), isophorone diisocyanate (IPDI), diphenylmethane diisocyanate (MDI), carbodiimide-modified MDI (liquefied MDI), polymethylene polyphenyl polyisocyanate (PAPI), dicyclohexylmethane diisocyanate (HMDI), hexamethylene diisocyanate (HDI), cyclohexyldimethylene diisocyanate (HXDI), and lysine diisocyanate (LDI); the compound containing a diamino group is 3,3- ’ -dichloro-4,4 ’ -Diaminodiphenylmethane or 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane.

[0013] The antioxidant is pentylenetetrazol-based dodecathiopropyl ester (… 412S), 4,4-bis(α,α-dimethylbenzyl)diphenylamine ( 445), bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite (ULTRANOX 627A), tetra(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate)pentaerythritol ester (1010), tris[2,4-di-tert-butylphenyl]phosphite (168), N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine (1098), pentaerythritol distearate phosphite (619), n-octadecyl (3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tetramethylene (3,5-di-tert-butyl-4-hydroxyphenylpropionate) methyl ester, bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]2,2-oxalamide, and bis(octadecyltetraol) diphosphite. More preferably, the antioxidant is a mixture of 4,4'-bis(α,α-dimethylbenzyl)diphenylamine and pentaerythritol distearate phosphite in a weight ratio of 2:1.

[0014] This invention also discloses a method for preparing the above-described high oil-resistant thermoplastic polyester elastomer composite material, comprising the following steps:

[0015] S1: Dissolve the chain extender in a solvent to obtain a chain extender solution;

[0016] S2: After mixing thermoplastic polyester elastomer, thermoplastic polyamide material, and chain extender solution evenly, add anti-grease amide composite lubricant, anti-grease stearic acid release agent, and antioxidant, and continue mixing evenly to obtain a mixture;

[0017] S3: The mixture from S2 is added to a twin-screw extruder for extrusion granulation to obtain the target product. Preferably, the processing temperature of the twin-screw extruder is 180-240℃, and the screw speed is 50-200 r / min.

[0018] Compared with the prior art, the beneficial effects of the present invention are reflected in:

[0019] This invention introduces polyamide bonds into the molecular chain by adding thermoplastic polyamide materials, thereby enabling thermoplastic polyester elastomers to exhibit grease resistance under high-temperature conditions. By dissolving the chain extender in a solvent and then adding it to the material, the amide segments and polyester polyether segments can be more organically linked to form more regular polymer segments, providing a solid molecular structure for temperature and grease resistance, and resulting in a high-performance thermoplastic polyester elastomer with higher grease resistance.

[0020] The composite material provided by this invention contains amide-based composite functional additives. When this material comes into contact with grease, the polar substances in the grease preferentially combine with the primary and secondary amine groups in the amide-based composite functional additives, preventing the grease from corroding the TPEE matrix resin. Each component in the amide-based composite functional additives plays a complementary role: specifically, primary amides such as oleamide and erucamide have relatively small molecular weights and easily migrate to the surface. Oleamide rapidly and efficiently reduces friction, with a significant initial effect; erucamide provides a long-lasting and stable slipping effect, has good temperature resistance, and takes a long time to produce its optimal effect; and aliphatic diamides, which are secondary amides, have larger molecular weights, lower volatility, and better thermal stability, and are less prone to migration. This makes it less likely for polar greases to cause performance loss to the material under high-temperature operating conditions.

[0021] The stearic acid additives in the composite material provided by this invention are easily precipitated to the material surface, and have an isolating and lubricating effect. This not only reduces processing energy consumption, but also prevents the intrusion of grease by precipitating its own substances at high temperatures, thereby greatly improving grease resistance and also reducing noise.

[0022] In addition to improving the grease resistance of composite materials, amide-based composite functional additives and stearic acid additives can also improve the lubrication performance of friction products and play a noise reduction role because the relatively small molecular weight primary amides such as oleamide and erucamide in amide-based composite functional additives and stearic acid additives are easily precipitated onto the material surface. Detailed Implementation

[0023] To facilitate understanding of the present invention, a more comprehensive description will be provided below with reference to specific embodiments. However, the present invention can be implemented in different forms and is not limited to the embodiments described herein.

[0024] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless otherwise specified, "parts" in the description refers to parts by weight.

[0025] The specific information of the raw materials used in the following examples and comparative examples is as follows:

[0026] Component A: Homemade TPEE. The preparation method of homemade TPEE is as follows:

[0027] 20 parts of dimethyl terephthalate, 18 parts of 1,4-butanediol, 30 parts of polytetrahydrofuran ether, 0.1 parts of 4,4'-bis(α,α-dimethylbenzyl)diphenylamine antioxidant, 0.25 parts of tetrabutyl titanate catalyst, and 0.3 parts of triphenyl phosphite anti-yellowing agent were added to a polymerization reactor. Polycondensation reaction was carried out at 250℃. Based on the change of stirring current in the reactor, a polyester elastomer resin with a melt index of 15 g / 10 min (230℃, 2.16 kg) was prepared.

[0028] Component B: Polyhexamethylene sebum diamine (PA610), Jinan Bojun Tuozhan New Materials Co., Ltd.

[0029] Component C: Amide-based composite functional additives are composed of the following components in the specified proportions:

[0030] C1: Ethylene bis-stearamide, Suzhou Liansheng Chemical Co., Ltd.

[0031] C2: Oleamide, Sichuan Ripu Fine Chemicals Co., Ltd.

[0032] C3: Erucamide, Croda, UK

[0033] Mix C1:C2:C3 = 3:5:2 (by weight) thoroughly and set aside.

[0034] Component D: Stearic acid additive is dipentaerythritol stearate, Shanghai Langzhen Industry Co., Ltd.

[0035] Component E: The chain extender is diphenylmethane diisocyanate (MDI), purchased from Nantong Ruifeng Petrochemical Co., Ltd.

[0036] Component F: The solvent is N,N-dimethylacetamide, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0037] Component G: The compound antioxidant is composed of the following components in the specified proportions:

[0038] G1: Antioxidant 4,4'-bis(α,α-dimethylbenzyl)diphenylamine, brand name Naugard N445, purchased from Kojuya Co., Ltd.;

[0039] G2: Pentaerythritol distearate (619), purchased from Kojuya Co., Ltd.

[0040] Mix G1 and G2 in a 2:1 ratio (by weight) thoroughly and set aside.

[0041] All materials are commercially available, commonly used products. The reagents described above are only for illustrating the source and composition of the reagents used in the experiments of this invention, in order to provide full disclosure, and do not imply that the invention cannot be achieved by using other similar reagents or reagents provided by other suppliers.

[0042] Any range described in this invention includes the endpoint, any value between the endpoints, and any subrange consisting of the endpoint or any value between the endpoints.

[0043] The weight parts of each component added in Comparative Examples 1-6 and Examples 1-3 are shown in Table 1, and the preparation methods are as follows:

[0044] S1: Preparation of saturated MDI solution: Dissolve MDI in N,N-dimethylacetamide (DMAC) until it no longer dissolves to obtain a saturated MDI solution;

[0045] S2: Weigh out the dried thermoplastic polyester elastomer, polyhexamethylene diamine (PA610), and saturated MDI liquid by weight and put them into a mixer and mix for 5 minutes. Then add amide composite functional additives, stearic acid additives, and antioxidants and mix for 5 minutes. After that, release the mixture for extrusion granulation.

[0046] S3: The material from S2 is fed into a twin-screw extruder for extrusion and granulation. The extrusion temperature of the twin-screw extruder is 230℃ and the length-to-diameter ratio is 40:1. After drying and packaging, the desired high oil-resistant thermoplastic polyester elastomer composite material is obtained.

[0047] Table 1 shows the component addition amounts in Comparative Examples 1-6 and Examples 1-3.

[0048] Components A B C D E F G Example 1 95 5 2 2 0.5 0.25 0.6 Example 2 90 10 1 1 1 0.5 0.6 Example 3 80 20 0.3 0.3 2 1 0.6 Comparative Example 1 100 1 0.5 0.6 Comparative Example 2 100 1 1 1 0.5 0.6 Comparative Example 3 90 10 0.6 Comparative Example 4 90 10 1 0.5 0.6 Comparative Example 5 90 10 1 1 0.5 0.6 Comparative Example 6 90 10 1 1 0.5 0.6

[0049] The tensile strength, elongation at break, and grease resistance of the high grease-resistant thermoplastic polyester elastomer materials prepared in the comparative examples and embodiments above were tested; the test results are shown in Table 2.

[0050] Grease resistance test method: Apply a layer of synthetic grease (2LN584 grease) evenly to the cut dumbbell-shaped sample, then place it in an oven at 140℃ and age it at this temperature for 336 hours before testing the tensile strength and elongation at break, and calculate its retention rate.

[0051] The noise level of a product during use is characterized by measuring its coefficient of friction. A coefficient of friction greater than 0.35 indicates low surface slipperiness and relatively high noise; a coefficient of friction between 0.15 and 0.35 indicates medium slipperiness and moderate noise; and a coefficient of friction between 0.01 and 0.15 indicates high slipperiness and relatively low noise. The lower the coefficient of friction, the smoother the product surface and the lower the noise during operation.

[0052] Table 2. Performance test results of the products prepared in the comparative examples and embodiments.

[0053]

[0054] As can be seen from Table 2: Comparative Example 1 did not contain thermoplastic polyamide material, amide composite functional additives, or stearic acid additives, and the material had already pulverized after grease aging; Comparative Example 2, although it did not contain thermoplastic polyamide material, contained amide composite functional additives and stearic acid additives, and the material had certain grease resistance; Comparative Examples 3 to 6 contained thermoplastic polyamide material, but did not contain other additives completely, and their performance retention rates were not as high as those in the examples, which exceeded 80% or even reached 100%; As can be seen from the examples, the simultaneous addition of amide composite functional additives and stearic acid additives not only improves grease resistance but also improves the smoothness of the material surface, thus giving the product a special property of noise reduction and ultra-high grease resistance.

[0055] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. The above descriptions are merely preferred embodiments of this application and are not intended to limit the scope of this application; that is, all equivalent modifications made within the scope of the claims of this application are within the protection scope of the claims of this application.

Claims

1. A high-oil-resistant thermoplastic polyester elastomer composite material, characterized in that: It is prepared from the following components in parts by weight: 80-95 parts of thermoplastic polyester elastomer, 5-20 parts of thermoplastic polyamide material Amide-based composite functional additives, 0.3-2 parts. Stearic acid additives 0.3-2 parts, Chain extender 0.5-2 parts, Solvent 0.25-1 part, Antioxidant 0.6 parts; The amide-based composite functional additive is a complex composed of oleamide, erucamide, and aliphatic bisamides; The preparation method of the high oil-resistant thermoplastic polyester elastomer composite material includes the following steps: S1: Dissolve the chain extender in a solvent to obtain a chain extender solution; S2: After mixing thermoplastic polyester elastomer, thermoplastic polyamide material, and chain extender solution evenly, add amide composite functional additives, stearic acid additives, and antioxidants, and continue mixing evenly to obtain a mixture; S3: Add the mixture from S2 to a twin-screw extruder for extrusion granulation to obtain the target product.

2. The high oil-resistant thermoplastic polyester elastomer composite material according to claim 1, characterized in that: The fatty diamide is at least one of ethylene bis-stearamide and ethylene bis-oleamide.

3. The high oil-resistant thermoplastic polyester elastomer composite material according to claim 1, characterized in that: The weight ratio of oleamide, erucamide, and aliphatic diamide is 3:5:

2.

4. The high oil-resistant thermoplastic polyester elastomer composite material according to claim 1, characterized in that: The stearic acid additive is at least one of stearic acid, zinc stearate, sodium stearate, aluminum distearate, glyceryl monostearate, and dipentaerythritol stearate.

5. The high oil-resistant thermoplastic polyester elastomer composite material according to claim 1, characterized in that: The thermoplastic polyamide material is at least one of PA6, PA66, PA611, PA612, PA610, PA612, PA1010, PA1012, PA510, PA513, PA516, and PA46.

6. The high oil-resistant thermoplastic polyester elastomer composite material according to claim 1, characterized in that: The chain extender is at least one of epoxy chain extenders, isocyanate chain extenders, and compounds containing diamino groups.

7. The high oil-resistant thermoplastic polyester elastomer composite material according to claim 6, characterized in that: The isocyanate chain extender is at least one of toluene diisocyanate, isophorone diisocyanate, diphenylmethane diisocyanate, carbodiimide-modified MDI, polymethylene polyphenyl polyisocyanate, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, cyclohexyldimethylene diisocyanate, and lysine diisocyanate.

8. The high oil-resistant thermoplastic polyester elastomer composite material according to claim 1, characterized in that: The antioxidant is at least one of the following: pentaerythritol dodecyl thiopropyl ester, 4,4-bis(α,α-dimethylbenzyl)diphenylamine, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, tetra(β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate)pentaerythritol ester, tris[2,4-di-tert-butylphenyl]phosphite, N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexamethylenediamine, pentaerythritol distearate phosphite, n-octadecyl (3,5-di-tert-butyl-4-hydroxyphenyl)propionate, tetramethylene (3,5-di-tert-butyl-4-hydroxyphenylpropionate) methyl ester, bis[ethyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)]2,2-oxalamide, and bis(octadecyltetraol) diphosphite.

9. The method for preparing the high oil-resistant thermoplastic polyester elastomer composite material according to any one of claims 1 to 8, characterized in that: Includes the following steps: S1: Dissolve the chain extender in a solvent to obtain a chain extender solution; S2: After mixing thermoplastic polyester elastomer, thermoplastic polyamide material, and chain extender solution evenly, add amide composite functional additives, stearic acid additives, and antioxidants, and continue mixing evenly to obtain a mixture; S3: Add the mixture from S2 to a twin-screw extruder for extrusion granulation to obtain the target product.

10. The method for preparing the high oil-resistant thermoplastic polyester elastomer composite material according to claim 9, characterized in that: The twin-screw extruder has a processing temperature of 180-240℃ and a screw speed of 50-200 r / min.

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