A high and low temperature resistant thermoplastic TPV and its applications

Abstract

This invention discloses a high- and low-temperature resistant thermoplastic TPV and its applications. The thermoplastic TPV comprises EPDM rubber, polypropylene, a plasticizer and an antioxidant, a modified fluoroplastic, a fluoroplastic masterbatch, sodium bicarbonate, and a crosslinking agent. The modified fluoroplastic is prepared from a modifier, a grafting agent, a hydroxyl polyhedral cage-like silsesquioxane, and a fluorine monomer. By utilizing a grafting agent containing unsaturated double bonds to undergo an addition reaction with the fluoroplastic, triazine and polyhedral cage-like silsesquioxane functional groups are introduced, significantly improving the material's temperature resistance and mechanical strength. The TPV of this invention exhibits excellent high- and low-temperature resistance, tensile strength, and elongation at break, as well as good compression set and brittle temperature performance.

Description

Technical Field

[0001] This invention relates to the field of TPV composite material technology, and in particular to a high and low temperature resistant thermoplastic TPV and its applications. Background Technology

[0002] With the continuous advancement of industrial technology and the development of materials science, TPV has been widely used in various fields such as automobiles, construction, and medicine due to its excellent physical properties and ease of processing. TPV is a polymer composite material prepared through dynamic vulcanization technology. It combines the thermoplasticity of plastics and the elasticity of rubber, and can maintain good performance over a wide temperature range.

[0003] However, the performance of existing TPV materials in extreme temperature environments still needs improvement. Especially under alternating high and low temperature conditions, the temperature resistance, mechanical strength, and aging resistance of traditional TPV materials often fail to meet increasingly stringent industrial demands. For example, in automotive sealing strips and building window and door seals, materials need to maintain shape and performance stability at high temperatures while retaining good elasticity and flexibility at low temperatures.

[0004] Furthermore, existing methods for preparing TPV materials also have certain limitations. Traditional preparation processes often require complex equipment and multi-step chemical reactions, which not only increases production costs but also limits further improvements in material performance. Therefore, developing a novel high- and low-temperature resistant thermoplastic TPV material and its preparation method to improve the material's temperature resistance and mechanical strength has become a research objective.

[0005] CN112745653A discloses modified polyphenylene ether (PPE), halogen-free flame-retardant TPV, their preparation methods and applications, and compositions for preparing halogen-free flame-retardant TPV. PPE, impact-resistant polystyrene, polybutene-1, and oil-extended SEBS are added to an extruder for plasticization and extrusion granulation. The modified PPE provided by this invention possesses high physical and mechanical properties and good flame-retardant properties; using this modified PPE can improve the mechanical and flame-retardant properties of halogen-free flame-retardant TPV. However, the TPV prepared by this invention has a relatively short service life under extreme temperature environments.

[0006] CN111057306A discloses a TPV composition and its preparation method, comprising 30-40 parts polypropylene, 20-30 parts EPDM rubber, 20-30 parts plasticizer, 10-20 parts filler, 0.2-1 parts lubricant, 0.2-1 parts crosslinking agent, 0.5-2 parts co-crosslinking agent, 0.3-0.5 parts antioxidant, and 1-5 parts porous adsorbent. This invention achieves high overmolding adhesive strength by adding special additives to the formulation. However, the mechanical strength of the TPV prepared by this invention is not high. Summary of the Invention

[0007] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is to improve the high and low temperature resistance and mechanical properties of thermoplastic TPV.

[0008] To achieve the above objectives, the present invention provides a high and low temperature resistant thermoplastic TPV, comprising the following components by weight: 20-40 parts EPDM rubber, 30-60 parts polypropylene, 1-3 parts softener, 2-5 parts antioxidant, 10-30 parts modified fluoroplastic, 10-40 parts fluoroplastic masterbatch, 1-4 parts sodium bicarbonate, and 1-5 parts crosslinking agent; wherein the modified fluoroplastic is prepared from a modifier, a grafting agent, a hydroxyl polyhedral cage-type silsesquioxane, and a fluorine monomer.

[0009] Preferably, the method for preparing the modified fluoroplastic includes the following steps:

[0010] S1: Dissolve the modifier in the solvent, stir evenly, add hydroxyl polyhedral cage-type silsesquioxane, heat to 90-100℃, then add palladium catalyst, stir evenly, filter, wash, dry, and cool to room temperature to obtain triazine-POSS nano-hybrid material.

[0011] S2: Mix water, dispersant and trifluorotrichloroethane evenly, add grafting agent, and purge with inert gas to a pressure of 1-2 MPa for 30-60 min. Then, evacuate to 0.02-0.09 MPa and add triazine-POSS nano-hybrid material. Add fluorine monomer to a pressure of 1-2 MPa, heat to 80-100℃ and add sodium persulfate. Stir at 300-500 rpm for 2-6 h to finally obtain modified fluoroplastic.

[0012] More preferably, the method for preparing the modified fluoroplastic includes the following steps, in parts by weight:

[0013] S1: Dissolve 20-50 parts by weight of the modifier in 500-2000 parts by weight of chloroform, and stir at 300-500 rpm for 30-60 min. Add 20-45 parts by weight of hydroxyl polyhedral cage-type silsesquioxane, heat to 90-100℃ and stir for 20-40 min. Then add 0.1-0.4 parts by weight of palladium catalyst, stir at 300-500 rpm at 90-100℃ for 7-10 h, filter, wash, dry at 50-70℃ for 12-24 h, and cool to room temperature to obtain triazine-POSS nano-hybrid material.

[0014] S2: Mix 50-70 parts water, 10-20 parts ammonium perfluorobutyl sulfonate and 10-30 parts trifluorotrichloroethane at 200-400 rpm for 5-10 min, add 8-15 parts grafting agent, purge with inert gas to a pressure of 1-2 MPa and maintain for 30-60 min, then evacuate to 0.02-0.09 MPa, add 30-50 parts triazine-POSS nano-hybrid material; add 80-150 parts fluorine monomer to a pressure of 1-2 MPa, heat to 80-100℃ and add 0.1-0.4 parts sodium persulfate, stir at 300-500 rpm for 2-6 h, and finally obtain modified fluoroplastics.

[0015] Preferably, the modifier is any one of 2,4-diamino-6-isopropenyl-1,3,5-triazine, 6-vinyl-1,3,5-triazine-2,4-diamine, and 2,4-diamino-6-styryl-s-triazine.

[0016] More preferably, the modifier is 2,4-diamino-6-styryl-s-triazine.

[0017] Preferably, the grafting agent is any one of N-methyl-N,N,N-tripropenylammonium chloride, dimethyl-bis(2-propenyl)ammonium chloride, and [(ethylene oxide-2-yl)methyl]bis(prop-2-en-1-yl)amine.

[0018] Preferably, the dispersant is any one of perfluorobutyl sulfonate ammonium or perfluorohexane-1-sulfonate ammonium.

[0019] Preferably, the antioxidant is any one of bisphenol A type antioxidants, phosphate ester antioxidants, and amine antioxidants.

[0020] A method for preparing high and low temperature resistant thermoplastic TPV includes the following steps, in parts by weight:

[0021] Step 1: Mix 20-40 parts of EPDM rubber, 30-60 parts of polypropylene, 1-3 parts of softener, and 2-5 parts of antioxidant at 3000 rpm for 10 minutes, knead in a kneader, and then extrude and granulate through a screw extruder to obtain mixture A.

[0022] Step 2: Mix 10-30 parts of modified fluoroplastic, 10-40 parts of fluoroplastic masterbatch, 1-4 parts of sodium bicarbonate and 1-5 parts of crosslinking agent evenly to obtain mixture B;

[0023] Step 3: Extrude mixture A and mixture B at a mass ratio of (20-50):100, vulcanize and foam them, and finally obtain high and low temperature resistant thermoplastic TPV.

[0024] This invention also provides an application of high and low temperature resistant thermoplastic TPV in automobiles, wires and cables, and building materials.

[0025] Technical concept:

[0026] Fluorine possesses extremely high thermal stability, and its addition can significantly improve the high and low temperature resistance of TPV materials. This allows TPV to maintain its physical and chemical properties over a wider temperature range, making it suitable for extreme temperature environments. However, directly adding fluorine may not be well compatible with other components in TPV, leading to uneven material properties. Therefore, modification can improve the compatibility of fluorine with other components, thereby ensuring the uniformity and consistency of the material. In the modification of fluoroplastics, grafting agents containing unsaturated double bonds can undergo addition reactions with fluoroplastics, chemically binding triazine and polyhedral cage-like silsesquioxane functional groups to the fluoroplastics. This binding method effectively prevents the migration of functional groups in TPV composites, thus ensuring the stability of material properties. The introduction of triazine and polyhedral cage-like silsesquioxane functional groups has a significant effect on improving the performance of TPV composites. First, these functional groups enhance the material's high and low temperature resistance, enabling TPV composites to maintain their physical and chemical properties over a wider temperature range. Secondly, the unique nano-hybrid cage structure of polyhedral cage-like silsesquioxanes forms crosslinks in fluoroplastics, significantly improving the mechanical properties of TPV composites. The nanoscale size and rigid structure of the polyhedral cage-like silsesquioxanes provide additional support for TPV, enhancing the material's strength and toughness. Furthermore, the introduction of triazine rings also provides additional stability and rigidity to the TPV composites. This structural reinforcement helps improve the material's resistance to stress, thereby enhancing the mechanical properties of TPV. In summary, by introducing triazine and polyhedral cage-like silsesquioxane functional groups into fluoroplastics, not only are the temperature resistance of TPV composites improved, but their mechanical strength and toughness are also significantly enhanced.

[0027] In this formula, the ingredients and their functions are as follows:

[0028] The modifier contains amino functional groups and triazine functional groups. The amino functional groups can react with the hydroxyl functional groups in the polyhedral cage-type silsesquioxane functional groups to form triazine-POSS nanohybrid materials.

[0029] Polyhedral cage-like silsesquioxanes react with modifiers to form nano-hybrid materials, enhancing the material's temperature resistance and mechanical properties. The unique nano-hybrid cage structure of polyhedral cage-like silsesquioxanes forms crosslinks in fluoroplastics, providing additional support and enhancing the material's strength and toughness.

[0030] Grafting agents containing double bonds can undergo addition reactions with fluoroplastics, thereby chemically bonding triazine functional groups and polyhedral cage-like silsesquioxane functional groups to the fluoroplastics. This bonding helps improve the material's resistance to high and low temperatures and its mechanical strength.

[0031] The beneficial effects of this invention are:

[0032] 1. Compared with existing technologies, this invention significantly improves the high and low temperature resistance of TPV composite materials by introducing triazine and polyhedral cage-like silsesquioxane functional groups onto fluoroplastics. This structural enhancement enables the TPV composite material to maintain its physical and chemical properties over a wider temperature range, thus maintaining good performance even in extreme temperature environments.

[0033] 2. Compared with the prior art, the TPV composite material of the present invention has significantly enhanced mechanical properties, including higher tensile strength, elongation at break and lower compression set, due to the nanoscale and rigid structure of the polyhedral cage-like silsesquioxane providing additional support for TPV, and the rigid structure of the triazine ring providing additional stability and rigidity to the material. Detailed Implementation

[0034] The parameters and sources of the specific chemical substances used.

[0035] (9ci)-4,6-Diethylene-1,3,5-Thiazin-2-amine, 1,3,5-Triazin-2-amine, 4,6-diethenyl-, CAS No.: 149037-13-8.

[0036] 2,4-Diamino-6-isopropenyl-1,3,5-triazine, CAS No.: 3194-71-6.

[0037] 6-Ethyl-1,3,5-triazine-2,4-diamine, CAS No.: 27154-03-6.

[0038] 2,4-Diamino-6-styryl-s-triazine, CAS No.: 7501-72-6.

[0039] N-Methyl-N,N,N-tripropenylammonium chloride, 2-Propen-1-aminium,N-methyl-N,N-di-2-propen-1-yl-,chloride(1:1), CAS No.: 26848-70-4.

[0040] Dimethyl-bis(prop-2-enyl)azanium chloride, CAS No.: 847780-23-8.

[0041] [(ethylene oxide-2-yl)methyl]bis(prop-2-en-1-yl)amine,

[0042] N,N-diallylglycidylamine, CAS number: 16719-00-9.

[0043] Antioxidant Irganox 107, BASF.

[0044] Fluoroplastic masterbatch, part number: FE 350LC, Solvay.

[0045] EPDM rubber, grade: 3745P, DowDuPont.

[0046] Polypropylene, grade: PPB-M02-V(K8003), Yangzi Petrochemical.

[0047] Palladium catalyst, item number: 96-4650, Beijing Bailingwei Technology Co., Ltd.

[0048] Example 1

[0049] A method for preparing high and low temperature resistant thermoplastic TPV includes the following steps:

[0050] Step 1: Mix 30 parts by weight of EPDM rubber, 50 parts by weight of polypropylene, 3 parts by weight of paraffin oil and 5 parts by weight of antioxidant Irganox 107 at 3000 rpm for 10 min, knead in a kneader, and then extrude and granulate through a screw extruder to obtain mixture A.

[0051] Step 2: Mix 10 parts by weight of modified fluoroplastic, 20 parts by weight of fluoroplastic masterbatch, 2 parts by weight of sodium bicarbonate and 4 parts by weight of benzoyl peroxide at 3000 rpm for 10 min to obtain mixture B;

[0052] Step 3: Mixture A and mixture B are passed through a twin-screw extruder at a mass ratio of 40:100 and dynamically vulcanized and foamed at 220°C; finally, the high-elasticity TPV composite material is obtained by pelletizing.

[0053] The method for preparing the modified fluoroplastic includes the following steps:

[0054] S1: Dissolve 30 parts by weight of 2,4-diamino-6-styryl-s-triazine in 1000 parts by weight of chloroform and stir at 300 rpm for 30 min. Add 30 parts by weight of trisiloxyphenyl cage-type silsesquioxane, heat to 90 °C and stir at 300 rpm for 20 min. Then add 0.2 parts by weight of palladium catalyst and stir at 90 °C and 300 rpm for 7 h. Filter to obtain filter residue, wash once with water, dry at 50 °C for 12 h, and cool to 25 °C to obtain triazine-POSS nano-hybrid material.

[0055] S2: Mix 60 parts by weight of water, 18 parts by weight of ammonium perfluorobutyl sulfonate and 25 parts by weight of trifluorotrichloroethane at 200 rpm for 10 min, add 10 parts by weight of [(ethylene oxide-2-yl)methyl]bis(prop-2-en-1-yl)amine, purge with nitrogen to a pressure of 2 MPa and maintain for 30 min, then evacuate to 0.07 MPa, add 40 parts by weight of triazine-POSS nano-hybrid material; add 100 parts by weight of tetrafluoroethylene monomer to a pressure of 2 MPa, heat to 100 °C, add 0.15 parts by weight of sodium persulfate, stir at 300 rpm for 4 h, and finally obtain modified fluoroplastics.

[0056] Example 2

[0057] The difference between Example 2 and Example 1 is that the [(ethylene oxide-2-yl)methyl]bis(prop-2-en-1-yl)amine in Example 1 is replaced with N-methyl-N,N,N-tripropenylammonium chloride.

[0058] Example 3

[0059] The difference between Example 3 and Example 1 is that the [(ethylene oxide-2-yl)methyl]bis(prop-2-en-1-yl)amine in Example 1 is replaced with dimethyl-bis(2-propenyl)ammonium chloride.

[0060] Example 4

[0061] The difference between Example 4 and Example 1 is that the 2,4-diamino-6-styryl-s-triazine in Example 1 is replaced with 2,4-diamino-6-isopropenyl-1,3,5-triazine.

[0062] Example 5

[0063] The difference between Example 5 and Example 1 is that the 2,4-diamino-6-styrene-s-triazine in Example 1 is replaced with 6-vinyl-1,3,5-triazine-2,4-diamine.

[0064] Comparative Example 1

[0065] The difference between Comparative Example 1 and Example 1 is that the [(ethylene oxide-2-yl)methyl]bis(prop-2-en-1-yl)amine in Example 1 is replaced with diallyl diethylammonium chloride.

[0066] Comparative Example 2

[0067] The difference between Comparative Example 2 and Example 1 is that the 2,4-diamino-6-styryl-s-triazine in Example 1 is replaced with (9ci)-4,6-diethylene-1,3,5-thiazine-2-amine.

[0068] Test Example 1

[0069] Tensile strength and elongation at break: Tested in accordance with GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber".

[0070] Hot air aging: Tested according to GB / T 7141-2008 "Test Method for Thermal Aging of Plastics".

[0071] Compression set: Tested in accordance with GB / T 1040.1-2018 "Determination of tensile properties of plastics - Part 1: General".

[0072] Brittleness temperature: Tested according to GB / T 1682-2014 "Determination of Low-Temperature Brittleness of Vulcanized Rubber - Single Specimen Method". Test results are shown in Table 1.

[0073] Table 1. Test Results of Mechanical and Temperature Resistance Properties

[0074]

[0075]

[0076] Comparing the tabular data in Examples 1-3 and Comparative Example 1, it was found that the high and low temperature resistant thermoplastic TPV prepared in Example 1 exhibited the best mechanical properties. This may be due to the use of different grafting agents. In this invention, by reacting the grafting agent with fluorinated monomers and triazine-POSS nano-hybrid materials, triazine and polyhedral cage-like silsesquioxane functional groups were introduced into the molecular chain of the fluoroplastic, improving the compatibility of the dispersed phases of silicone rubber, fluoroplastics, and other raw materials. Compared to the grafting agents in Examples 1-3 and Comparative Example 1, the grafting agent in Example 1 contained not only the double bonds involved in the reaction but also epoxy groups. Epoxy groups can react with the amine groups contained in the modifier and the hydroxyl groups contained in the polyhedral cage-like silsesquioxane functional groups, increasing the crosslinking density of the TPV material. Higher crosslinking density generally implies better mechanical properties, including higher strength and toughness. Furthermore, the epoxy groups can react further to act as compatibilizers, improving the compatibility between different polymer components and thus enhancing the stability of the TPV material. The grafting agents used in Examples 2-3 and Comparative Example 1 do not contain epoxy groups, resulting in a lower crosslinking density in the prepared TPV materials. Consequently, these materials exhibit poorer mechanical properties and a shorter lifespan when exposed to high and low temperatures. At low temperatures, the triazine-POSS nanohybrid material and its rigid structure help maintain the material's flexibility and resistance to embrittlement, thereby improving the TPV's low-temperature resistance. Therefore, the TPV material prepared in Example 1 exhibits better high and low temperature resistance.

[0077] Comparing the tabular data in Examples 1, 4-5, and Comparative Example 1, it was found that the high- and low-temperature resistant thermoplastic TPV prepared in Example 1 exhibited the best mechanical properties. This may be due to the use of different modifiers. The modifier in Example 1, in addition to containing amino functional groups that react with the hydroxyl groups in polyhedral cage-like silsesquioxanes, also contained a rigid benzene ring structure. The rigid structure of the benzene ring reinforces the internal framework of the TPV, improving its rigidity and strength. Simultaneously, the stability and rigidity of the benzene ring help maintain the shape and structure of the TPV at high temperatures, thereby improving the material's heat resistance and allowing it to maintain good stability and exhibit excellent high-temperature performance. In contrast, the modifiers used in Examples 4-5 and Comparative Example 2 only contained amino functional groups and did not contain a rigid large benzene ring structure, resulting in TPV materials with poorer mechanical properties.

Claims

1. A method for preparing high and low temperature resistant thermoplastic TPV, characterized in that, The process includes the following steps: Step 1: Mix 30 parts by weight of EPDM rubber, 50 parts by weight of polypropylene, 3 parts by weight of paraffin oil and 5 parts by weight of antioxidant Irganox 107 at 3000 rpm for 10 min, knead in a kneader, and then extrude and granulate through a screw extruder to obtain mixture A. Step 2: Mix 10 parts by weight of modified fluoroplastic, 20 parts by weight of fluoroplastic masterbatch, 2 parts by weight of sodium bicarbonate and 4 parts by weight of benzoyl peroxide at 3000 rpm for 10 min to obtain mixture B; Step 3: Mixture A and mixture B are passed through a twin-screw extruder at a mass ratio of 40:100 and dynamically vulcanized and foamed at 220°C; finally, the high-elasticity TPV composite material is obtained by pelletizing. The method for preparing the modified fluoroplastic includes the following steps: S1: Dissolve 30 parts by weight of 2,4-diamino-6-styryl-s-triazine in 1000 parts by weight of chloroform and stir at 300 rpm for 30 min. Add 30 parts by weight of trisiloxyphenyl cage-type silsesquioxane, heat to 90 °C and stir at 300 rpm for 20 min. Then add 0.2 parts by weight of palladium catalyst and stir at 90 °C and 300 rpm for 7 h. Filter to obtain filter residue, wash once with water, dry at 50 °C for 12 h, and cool to 25 °C to obtain triazine-POSS nano-hybrid material. S2: Mix 60 parts by weight of water, 18 parts by weight of ammonium perfluorobutyl sulfonate and 25 parts by weight of trifluorotrichloroethane at 200 rpm for 10 min, add 10 parts by weight of [(ethylene oxide-2-yl)methyl]bis(prop-2-en-1-yl)amine, purge with nitrogen to a pressure of 2 MPa and maintain for 30 min, then evacuate to 0.07 MPa, add 40 parts by weight of triazine-POSS nano-hybrid material; add 100 parts by weight of tetrafluoroethylene monomer to a pressure of 2 MPa, heat to 100 °C, add 0.15 parts by weight of sodium persulfate, stir at 300 rpm for 4 h, and finally obtain modified fluoroplastics.

2. The application of the high and low temperature resistant thermoplastic TPV as described in claim 1 in automobiles, wires and cables, and building materials.

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