CN1445279A - Thermoplastic elastomer made from nylon/ethylene propylene rubber and its preparing method - Google Patents

Abstract

A thermoplastic nylon/ethylene propylene rubber elastomer is prepared from ethylene propylene rubber, nylon, chlorinated polyethylene as compatibilizer, and cross-linking system through mixing nylon with ethylene propylene rubber, adding said compatibilizer, and pugging in banburying machine or screw extruding for shearing while adding sulfur (or peroxide) cross-linking agent for sulfurizing said rubber. Its advantages are simple process, high solvent resistance and low cost.

Description

Nylon/ethylene propylene rubber thermoplastic elastomer and preparation method thereof

Technical field:

The invention relates to a fully dynamic crosslinked nylon/ethylene propylene rubber thermoplastic elastomer and a preparation method thereof.

Background technique:

Polymer blends with both thermoplasticity and elasticity are generally prepared by dispersing a thermoplastic and an elastomer composition (rubber) in a way that allows the elastomer to be densely and uniformly dispersed in the thermoplastic in discontinuous particles. obtained by blending in the continuous phase. Early research work on blended vulcanized elastomers was found in USP 3,037,954, which disclosed static vulcanization technology and dynamic vulcanization technology. In dynamic vulcanization technology, vulcanizable elastomers are dispersed in resinous thermoplastic aggregates. , and the elastomer is vulcanized while continuously stirring and shearing the polymer blend. The resulting blend (vulcanized rubber or dynamically vulcanized blend) is a microgel dispersion of an elastomer in a matrix of unvulcanized thermoplastic polymers such as polypropylene, such as butyl rubber, chlorinated Dispersions of butyl rubber, polybutadiene or polyisobutylene in which this technology has been significantly developed.

USP.5,525,668 and USP.5,397,835 relate to a preparation method of a novel thermoplastic elastomer. It is the process of dispersing polyolefin elastomer material containing functionalized EPM or EPDM into polyamide resin, and then vulcanizing the elastomer phase. The elastomer phase is dispersed in the polyamide resin phase in the form of fine particles, and the resulting mixture has thermoplastic characteristics as a whole. The resulting blend can be used to prepare elastomeric materials without the need for a separate vulcanization process.

European polymer journal 2002, v38, 857-61 reported the preparation of dynamically vulcanized blended thermoplastic elastomers with terpolymerized nylon and ethylene-propylene rubber. The compatibilizer used was ethylene-propylene rubber functionalized with maleic anhydride. The prepared The thermoplastic elastomer material has good mechanical properties. However, the ethylene-propylene rubber grafted with maleic anhydride has a strong stimulating effect on the human body due to the presence of acid anhydride groups, causing production personnel to shed tears, allergies and other discomfort reactions. In addition, the ethylene-propylene rubber grafted with maleic anhydride is expensive.

Invention content:

The object of the present invention is to provide a nylon/ethylene propylene rubber thermoplastic elastomer with improved physical properties and superior processability and a preparation method thereof.

The present invention adopts chlorinated polyethylene as compatibilizer, chlorinated polyethylene has the advantage of no toxic and side effects, chlorinated polyethylene is cheap, and adopts chlorinated polyethylene as compatibilizer to prepare nylon and ethylene-propylene rubber dynamic vulcanization Comparing the blended thermoplastic elastomer with maleic anhydride grafted ethylene-propylene rubber as a compatibilizer, the mechanical properties of the blended thermoplastic elastomer with dynamic vulcanization of nylon and ethylene-propylene rubber are further improved.

Nylon/ethylene propylene rubber thermoplastic elastomer of the present invention is made up of ethylene propylene rubber, nylon, compatibilizer, cross-linking system, wherein ethylene propylene rubber is 100 weight parts, nylon consumption is 25-1000 weight parts, and compatibilizer consumption is 5-900 parts by weight, and the amount of the cross-linking system is 2-20 parts by weight.

The ethylene-propylene rubber used in the present invention is ethylene-propylene-diene rubber in which ethylidene norbornene is the third monomer, wherein it consists of 50-65% ethylene monomer, 30-40% propylene monomer, 5%-10% ethylidene norbornene and its derivatives, abbreviated as EPDM.

The nylon that the present invention adopts is the ternary copolymerized nylon that contains caprolactam monomer, hexamethylenediamine adipic acid monomer, and decanediamine sebacic acid monomer copolymerized to form, and copolymerized nylon is that comonomer weight ratio is caprolactam monomer/ Hexamethylenediamine adipic acid monomer/decanediamine sebacic acid monomer = 20/10/70 terpolymer, abbreviated as PA.

The compatibilizer adopted in the present invention is chlorinated polyethylene with a chlorine content of 35% ± 5, abbreviated as CPE;

The cross-linking system adopted in the present invention is sulfur cross-linking system I, peroxide cross-linking system II, III.

(1) The components of the sulfur crosslinking system I are based on 100 parts by rubber weight:

(A) Sulfur, abbreviated as S 1-10 parts;

(B) zinc oxide, abbreviated as ZnO 2-20 parts;

(C) Stearic acid, abbreviated as SA 1-5 parts;

(D) Tetramethylthiuram disulfide, abbreviated as TMTD 0.5-2 parts;

(E) Dibenzothiazole disulfide, abbreviated as DM 0.2-1.0 parts;

(2) The components of the peroxide crosslinking system II are based on 100 parts by rubber weight:

(A) 2.5-dimethyl-2.5-di-tert-butylperoxyhexane, abbreviated as double 2,5 1-10 parts;

(B) m-phenylene bismaleimide, abbreviated as HVA-2 0.5-5 parts;

(3) The components of the peroxide crosslinking system III are based on 100 parts by rubber weight:

(A) Dicumyl peroxide, abbreviated as DCP 1-10 parts;

(B) m-phenylene bismaleimide 0.5-5 parts;

The preparation method of the nylon/ethylene-propylene rubber thermoplastic elastomer of the present invention comprises adding the following ingredients in an internal mixer, an open mill or a screw extruder at a blending temperature of 150-200°C: ethylene-propylene rubber, ternary Copolymerize nylon, compatibilizer chlorinated polyethylene, and cross-linking system. After blending for 5-8 minutes, the blend is crushed, and then blended for 4-5 minutes to obtain a high-performance dynamic vulcanized nylon/ethylene-propylene rubber copolymer. Hybrid thermoplastic elastomer.

Nylon/ethylene propylene rubber thermoplastic elastomer of the present invention is to adopt chlorinated polyethylene compatibilizer to join in nylon/ethylene propylene rubber blend to improve nylon and ethylene propylene rubber blending compatibility, while shearing, add sulfur The cross-linking system or peroxide cross-linking system vulcanizes ethylene-propylene rubber, and the phase inversion occurs, changing from nylon dispersed in the rubber continuous phase to cross-linked micron-sized rubber particles dispersed in the nylon continuous phase, resulting in high rubber content High performance nylon/ethylene propylene rubber blend thermoplastic elastomer. The thermoplastic elastomer prepared by the method has simple processing technology, low production cost and good chemical solvent resistance. It can be used to prepare high-strength rubber products.

The main performance of the prepared nylon/ethylene propylene rubber thermoplastic elastomer of the present invention is as follows:

Hardness: (Shore A) 65-90

 100% tensile strength: 3.5-8MPa

  Tensile strength: 6.0-45MPa

  Elongation at break: 104-466%

  Permanent deformation: 10-100%

  Long-term use temperature: -30-135°C

  Short-term use temperature: 150°C

Compared with ordinary non-tire rubber, the present invention has the following advantages: vulcanization is not required, and the processing technology adopts thermoplastic processing methods (extrusion, injection and molding, etc.), which saves energy and resources (the leftovers can be recycled), and saves equipment resources , shorten the production cycle and improve labor productivity. Compared with the EPDM/PP blended thermoplastic elastomer of the same kind of rubber fully cross-linked and accelerated cross-linked system, the present invention has better high temperature resistance and resistance to organic solvents. and aging resistance. The appearance of the product is smooth and flat. When peroxide is used as vulcanizing agent, it does not corrode metal materials such as copper, and can also be used as insulating material for wire and cable industry and other non-tire rubber products.

Detailed ways:

The following examples are to further illustrate the present invention, but not to limit the scope of the present invention.

The test standard that embodiment adopts:

Tensile strength GB527-83,

Hardness GB531-83.

Example 1: Heat the closed rubber and plastic mixer to 180°C, put EPDM, CPE, and PA in the formula listed in Table 1 into the internal mixer, and after the materials are melted and mixed evenly, add various crosslinking system, the rotor speed is 80 rpm, and after blending for 8 minutes, the mixture is taken out and pulverized, and blended for another 4 minutes to disperse the dispersed phase particles evenly.

      Table 1 Properties of thermoplastic elastomers using different crosslinking systems:

Formulation composition/parts by weight 1 2 3

EPDM 80 80 80

PA 54 54 54

CPE 20 20 20

S S 2 1

ZnO 5

                         

DM 0.5

TMTD 1

Double 2, 5 1

DCP 3

HVA-2

Mechanical properties

Tensile strength (MPa) 15.3 11.7 14.8

Elongation at break (%) 309 190 227

Hardness (shore A) 89 92 82

Example 2: Heat the closed rubber-plastic mixer to 180°C, put EPDM, CPE, and PA in the formula listed in Table 2 into the internal mixer, and after the materials are melted and mixed evenly, add different amounts of sulfur respectively For the cross-linking system, the rotor speed is 80 rpm. After blending for 8 minutes, the mixture is taken out and pulverized, and blended for another 4 minutes to make the dispersed phase particles uniformly dispersed.

        Table 2: Effect of sulfur content on the properties of thermoplastic elastomers

Formulation composition/parts by weight

EPDM 80 80 80 80 80 80

PA 54 54 54 54 54 54

CPE 20 20 20 20 20 20

S S 0 0.5 1 1.5 2 2.5

ZnO 5 5 5 5 5 5 5

SA 2 2 2 2 2 2 2

DM 0.5 0.5 0.5 0.5 0.5 0.5

TMTD 1 1 1 1 1 1 1

mechanical properties

Tensile Strength (MPa) 3.2 7.3 13 13.2 15.3 12

Elongation at break (%) 104 280 320 310 309 253

Hardness (shore A) 81 83 83 85 89 90

Permanent deformation (%) 2 19 15 7 28 11

Example 3: Heat the closed rubber-plastic mixer to 180°C, put EPDM, CPE, and PA in the formula listed in Table 3 into the internal mixer, then add sulfur crosslinking system, and wait until the materials are melted and mixed evenly Finally, the rotor speed is 80 rpm, and after blending for 8 minutes, the mixture is taken out and pulverized, and blended for another 4 minutes to disperse the dispersed phase particles evenly.

           Table 3: Influence of the amount of compatibilizer CPE on thermoplastic elastomer Formula composition/parts by weight

EPDM 100 90 80 70 50 30 20 10 0

PA 54 54 54 54 54 54 54 54 54

CPE 0 10 20 30 50 70 80 90 100

S 2 2 2 2 2 2 2 2 2 2 2

ZnO 5 5 5 5 5 5 5 5 5 5

SA 2 2 2 2 2 2 2 2 2 2 2

DM 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

TMTD 1 1 1 1 1 1 1 1 1 1 Mechanical Performance Anti -Zhang strength (MPA) 6.6 11.9 15.5 1616.2 20 21.6 24.7 Fracture elongation ( %) 163 286 309 360 368 365 384 466 Hardness (SHORE A) 88 88 89 87 88 83 83 83 91 Permanent deformation (%) 11 22 28 22 33 38 40 42 44

Example 4: Heat the closed rubber-plastic mixer to 180°C, put EPDM, CPE, and PA in the formula listed in Table 4 into the internal mixer, then add sulfur crosslinking system, and wait until the materials are melted and mixed evenly Finally, the rotor speed is 80 rpm, and after blending for 8 minutes, the mixture is taken out and pulverized, and blended for another 4 minutes to disperse the dispersed phase particles evenly.

        Table 4: Effect of Nylon Content on Thermoplastic Elastomer Formula Composition/Parts by Weight

EPDM 80 80 80 80 80 80 80 80 80

PA 33 43 54 66 100 150 233 400 900

CPE 20 20 20 20 20 20 20 20 20

S 2 2 2 2 2 2 2 2 2 2 2

ZnO 5 5 5 5 5 5 5 5 5 5

SA 2 2 2 2 2 2 2 2 2 2 2

DM 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5 0.5

TMTD 1 1 1 1 1 1 1 1 1 1 Mechanical Performance Anti -Zhang strength (MPA) 9.3 10.8 15.3 11.8 12.6 22.5 28.6 46 Fracture and elongation rate ( %) 220 278 309 289 162 171 345 411 hardness (Shore A) 82 86 89 89 94 95 96 96 96 Permanent deformation (%) 4 12 28 24 26 28 100 156 200

Claims (3)

1. a nylon/ethylene-propylene rubber thermoplastic elastomer is made up of ethylene-propylene rubber and nylon, compatibilizer, cross-linking system, is characterized in that: (1) The ethylene-propylene rubber in the thermoplastic elastomer is EPDM rubber in which ethylidene norbornene is the third monomer, and the nylon is ethylene-propylene-diene rubber containing caprolactam monomer, hexamethylenediamine adipic acid monomer, and decanediamine-decanediamine. Terpolymerized nylon formed by copolymerization of acid monomers; the comonomer weight ratio of terpolymerized nylon is caprolactam monomer/hexamethylenediamine adipic acid monomer/decanediamine sebacic acid monomer=20/10/70 Terpolymer; (2) The cross-linking system is a sulfur cross-linking system and a peroxide cross-linking system; (3) The compatibilizer is chlorinated polyethylene with a chlorine content of 35%±5; (4) The parts by weight of the thermoplastic elastomer are: (A) Ethylene Propylene Rubber 100 parts; (B) Nylon 25-1000 copies; (C) Compatibilizer 5-900 parts; (D) Cross-linking system 2-20 parts. 2. a kind of nylon/ethylene propylene rubber thermoplastic elastomer according to claim 1, is characterized in that: Sulfur crosslinking system I with sulfur as the main body and peroxide crosslinking system II and III with peroxide as the main body: (1) The components of the crosslinking system I are based on 100 parts by weight of rubber: (A) sulfur 1-10 parts; (B) Zinc oxide 2-20 parts; (C) 1-5 parts of stearic acid; (D) Tetramethylthiuram disulfide 0.5-2 parts; (E) 0.2-1.0 parts of dibenzothiazole disulfide; (2) The components of the cross-linking system II are based on 100 parts by weight of rubber: (A) 1-10 parts of 2.5-dimethyl-2.5-di-tert-butylperoxyhexane; (B) m-phenylene bismaleimide 0.5-5 parts; (3) The components of the crosslinking system III are based on 100 parts by weight of rubber: (A) 1-10 parts of dicumyl peroxide; (B) m-phenylene bismaleimide 0.5-5 parts; 3. A preparation method of nylon/ethylene-propylene rubber thermoplastic elastomer, which is characterized in that in a banbury mixer, an open mill or a screw extruder, at a blending temperature of 150-200° C., the following components are added: Propylene rubber; ternary copolymerized nylon; compatibilizer chlorinated polyethylene; cross-linking system; after blending for 5-8 minutes, the blend is pulverized, and then blended for another 4-5 minutes to obtain high-performance dynamic vulcanized nylon / Ethylene Propylene Rubber Blended Thermoplastic Elastomer.