CN105255026B - A kind of reactive compatibilization butyl rubber/polyamide thermoplastic vulcanizate and preparation method thereof - Google Patents

Abstract

The present invention relates to a kind of reactive compatibilization butyl rubber/polyamide thermoplastic vulcanizate and preparation method thereof.Method by the way that butyl rubber, bifunctional compound, radical initiator are mixed at high temperature, prepare the butyl rubber of bifunctional compound graft modification, then by the use of the butyl rubber of graft modification as bulking agent, premixed using rubber and plastic, the butyl rubber with excellent physical mechanical property, air-tightness, hardness etc./polyamide thermoplastic vulcanizate is prepared in the technology of dynamic vulcanization.

Description

A kind of reactive compatibilization butyl rubber/polyamide thermoplastic vulcanizate and its preparation method

Technical field:

The invention relates to a reactive compatibilization butyl rubber/polyamide thermoplastic vulcanizate and a preparation method thereof. It belongs to the field of polymer materials.

Background technique:

Thermoplastic vulcanizate is a special thermoplastic elastomer obtained by dynamic vulcanization reaction processing technology. When a small amount of plastic phase is melt-blended with a large amount of rubber, the rubber is chemically cross-linked under the action of the cross-linking agent, and the viscosity increases, so it is broken into micron-sized rubber particles under the action of strong mechanical shear, and finally forms the following Rubber is the dispersed phase and plastic is the special phase structure of the continuous phase. This special structure makes thermoplastic vulcanizate not only have the high elasticity and softness of traditional rubber, but also have the properties of thermoplastic processing and recyclability of plastics.

As a tire innerliner material, it needs to have certain mechanical properties, the hardness should not be too high, and the most important thing is to have excellent gas barrier properties. Both butyl rubber and polyamide are materials with excellent airtightness. The thermoplastic vulcanizates prepared by the dynamic vulcanization process have excellent airtightness and can be applied to tire inner liners, refrigerator hoses or gas barrier materials Lining etc. Compared with the traditional thermosetting tire inner liner, it is lighter in weight and better in air tightness. However, butyl rubber has poor compatibility with polyamide. Therefore, for the butyl rubber/polyamide system, it is difficult to improve the compatibility of the two and reduce the hardness. Usually in the preparation process of butyl rubber/polyamide TPV, we will add compatibilizer to improve the compatibility between the two, so as to obtain products with good performance. Patent CN 102964702 A discloses a polyamide/bromobutyl rubber thermoplastic elastomer and its preparation method and application. It dynamically vulcanizes bromobutyl rubber and ternary copolymerized polyamide in an internal mixer, respectively, with chlorine Polyethylene (CPE) and polyethylene octene copolymer grafted with maleic anhydride (POE-g-MAH) were used as compatibilizers, but the particle size of the dispersed phase of the obtained thermoplastic vulcanizate was large and the phase structure was not fine. Patent CN 103030895 A discloses a thermoplastic vulcanizate with high gas barrier performance and its preparation method. In the chlorinated butyl rubber/polyamide 12 system, a self-made compatibilizer (chlorinated butyl rubber, polyisobutylene, The "premix" of anhydride) is dynamically vulcanized in a twin-screw to obtain a thermoplastic vulcanizate with excellent mechanical properties and gas barrier properties. The above invention patents all improve the performance of TPV by adding a compatibilizer, but the compatibilizing effect cannot meet the high requirements of industrial production. The present invention adopts the graft-modified butyl rubber of a bifunctional compound as a compatibilizer, and through a dynamic vulcanization technology, prepares a thermoplastic vulcanizate that is superior to the prior art in terms of physical and mechanical properties, air tightness, hardness, and the like.

Invention content:

The object of the present invention is to provide a reactive compatibilized butyl rubber/polyamide thermoplastic vulcanizate and a preparation method thereof. By mixing butyl rubber, a bifunctional compound, and a free radical initiator at high temperature, a butyl rubber graft-modified by a bifunctional compound is prepared, and then the graft-modified butyl rubber is used as a compatibilizer, The butyl rubber/polyamide thermoplastic vulcanizate with excellent air tightness, hardness and other physical and mechanical properties is prepared by rubber and plastic premixing and dynamic vulcanization technology.

A kind of reactive compatibilization butyl rubber/polyamide thermoplastic vulcanizate provided by the present invention, its basic composition and mass parts are as follows:

The self-made compatibilizer is butyl rubber grafted with a difunctional compound under the action of a free radical initiator, and the mass ratio of butyl rubber, difunctional compound and free radical initiator is 100:0.01-20:0.01-5 .

The bifunctional compound is a small molecule monomer containing two functional groups, A and B. The A functional group can react with butyl rubber under the action of a free radical initiator, and the B functional group can react with the terminal amino group in the polyamide. react. The difunctional compound is selected from glycidyl methacrylate, 1,2-epoxybutene or acrylic anhydride. The free radical initiator is dicumyl peroxide or dibenzoyl peroxide.

The self-made compatibilizer is prepared by the following method: melt and mix butyl rubber, bifunctional compound and free radical initiator at 150°C-230°C for 3-20 minutes to obtain a graft-modified butyl rubber self-made compatibilizer .

The butyl rubber is one of halogen-free butyl rubber, chlorinated butyl rubber or brominated butyl rubber; the polyamide is polyamide 1010, polyamide 12 or polyamide 1212.

The antioxidant is hindered phenolic antioxidant 1010; the antioxidant is 2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD); the vulcanizing agent is zinc oxide ZnO; The additive is N,N'-m-phenylene bismaleimide (HVA-2).

The present invention also provides a method for preparing butyl rubber/polyamide thermoplastic vulcanizate through the above-mentioned reactive compatibilization, and the specific steps of the preparation method are as follows:

(1) Melt and mix butyl rubber, bifunctional compound, and free radical initiator at 150°C to 230°C for 3 to 20 minutes to obtain a graft-modified butyl rubber self-made compatibilizer;

(2) Rubber and plastic premixing: first mix the dried polyamide and butyl rubber at 180°C to 210°C, add antioxidant and self-made compatibilizer obtained in step (1) in proportion, and mix well The final discharge is cooled to room temperature; then mixed evenly with anti-aging agent, plasticizer, vulcanizing agent and vulcanization assistant at room temperature to obtain a rubber-plastic premix;

(3) Dynamic vulcanization: Put the rubber and plastic premix obtained in step (2) in a screw extruder, set the screw temperature at 180°C to 210°C, and the rotation speed at 300 to 700rpm, and dynamically vulcanize to obtain butyl rubber/polyamide thermoplastic vulcanization glue.

The advantage of the present invention is that the grafted modified butyl rubber of a bifunctional compound is used as a compatibilizer, and the physical and mechanical properties, air tightness, hardness, etc. are superior to the existing Proprietary high gas barrier thermoplastic vulcanizate.

Non-polar butyl rubber has poor compatibility with polar polyamides, and how to improve the compatibility of the two is also a key technology for preparing high gas barrier thermoplastic vulcanizates. The bifunctional compound used in the present invention is a small molecule monomer containing two functional groups, A and B, and the A functional group can react with butyl rubber to obtain a graft polymer under the action of a free radical initiator; The terminal amino group in the amide reacts to play a reactive compatibilizing effect. Moreover, the technology of rubber and plastic premixing and dynamic vulcanization is used to prepare the high gas barrier thermoplastic vulcanizate which is superior to the existing patents in terms of physical and mechanical properties, air tightness, hardness, etc., which is novel and practical.

Description of drawings:

Accompanying drawing 1 is the backscatter scanning electron microscope picture of embodiment 2.

Accompanying drawing 2 is the backscatter scanning electron microscope picture of comparative example 2.

The dark part in the figure is the rubber phase, and the light part is the plastic phase. It can be seen from the figure that the microstructure of TPV obtained by dynamic vulcanization of polyamide and chlorobutyl rubber without graft modified chlorobutyl rubber (compatibilizer) is relatively rough, and the size of the rubber dispersed phase is about 8 μm ; and after adding self-made compatibilizer, the phase structure of TPV obtained by dynamic vulcanization of polyamide and chlorobutyl rubber is relatively fine, and the size of the dispersed phase is about 3 μm, indicating that the butyl rubber grafted with bifunctional compounds can be very It plays a good role in compatibilizing the polyamide and chlorobutyl rubber system, and is conducive to the preparation of TPV with fine structure and good performance.

The present invention will be further described below in conjunction with embodiment:

Detailed ways:

The tensile strength, elongation at break and Shore A hardness in the examples were determined according to the following standards GB/T528-2009, GB/T528-2009 and GB/T531.1-2008 respectively. The gas permeability coefficient is tested according to the ISO2782 standard (self-made automatic air tightness tester), and the test conditions are: 40°C, N ₂ atmosphere.

Example 1:

The basic composition and mass parts of the selected raw materials are as follows:

Wherein the basic composition and mass ratio of self-made compatibilizer are:

Halogen-free butyl rubber 100;

Glycidyl methacrylate 0.01;

Dicumyl peroxide 1

According to the above formula, first melt and mix halogen-free butyl rubber, glycidyl methacrylate, and dicumyl peroxide in a Haake internal mixer at 150°C for 5 minutes to obtain graft-modified halogen-free butyl rubber; then mix the dried polyamide 1010 with halogen-free butyl rubber at 190°C, add graft-modified halogen-free butyl rubber and antioxidants in proportion, wait until the mixture is uniform, and then discharge and cool to room temperature ; then mix with anti-aging agent, plasticizer, vulcanizing agent and vulcanization aid at room temperature to obtain a rubber-plastic premix; place the rubber-plastic premix in a screw extruder, set the vulcanization temperature to 210°C, and 300rpm, dynamic vulcanization to obtain butyl rubber/polyamide thermoplastic vulcanizate. The TPV was pressed into a 2mm thick sheet according to the standard and the performance was tested. The performance is shown in Table 1.

Comparative example 1

According to the formula of Example 1 but without adding the halogen-free butyl rubber (compatibilizer) graft-modified by the bifunctional compound, under the same conditions, use the same method to dynamically vulcanize to prepare TPV, and press it into 2mm thick according to the standard Thin slices and test performance, the performance is shown in Table 1.

Example 2:

The basic composition and mass parts of the selected raw materials are as follows:

Wherein the basic composition and mass ratio of self-made compatibilizer are:

Chlorobutyl rubber 100

1,2-Epoxybutene 0.5

Dicumyl peroxide 0.1

According to the above formula, chlorinated butyl rubber, 1,2-epoxybutene, and dicumyl peroxide were melted and mixed in a Haake internal mixer at 170°C for 8 minutes to obtain graft-modified butyl chloride. base rubber; then mix the dried polyamide 1212 and chlorinated butyl rubber at 200°C, add graft-modified chlorinated butyl rubber and antioxidants in proportion, wait until the mixture is uniform, and then discharge and cool to room temperature; then mix it with anti-aging agent, plasticizer, vulcanizing agent and vulcanization aid at room temperature to obtain a rubber-plastic premix; put the rubber-plastic premix in a screw extruder, set the vulcanization temperature to 200°C, The rotating speed is 500rpm, and the butyl rubber/polyamide thermoplastic vulcanizate is obtained through dynamic vulcanization. The TPV was pressed into a 2mm thick sheet according to the standard and the performance was tested. The performance is shown in Table 1.

Comparative example 2

According to the formula of Example 2 but without adding the chlorinated butyl rubber graft-modified by the bifunctional compound, under the same conditions, use the same method to dynamically vulcanize to prepare TPV, press it into a 2mm thick sheet according to the standard and test the performance, The properties are shown in Table 1.

Example 3:

The basic composition and mass parts of the selected raw materials are as follows:

Wherein the basic composition and mass ratio of self-made compatibilizer are:

Bromobutyl rubber 100

Acrylic anhydride 5

Dicumyl peroxide 3

According to the above formula, first melt and mix bromobutyl rubber, acrylic anhydride, and dicumyl peroxide in a Haake internal mixer at 190°C for 10 minutes to obtain graft-modified bromobutyl rubber; then bake Mix dry polyamide 12 and bromobutyl rubber at 210°C, add graft-modified bromobutyl rubber and antioxidants in proportion, wait for the mixture to be uniform, and then discharge and cool to room temperature; Mix with anti-aging agent, plasticizer, vulcanizing agent and vulcanization auxiliary agent to obtain rubber and plastic premix; put the rubber and plastic premix in the screw extruder, set the vulcanization temperature to 190°C, and the speed to 700rpm, and dynamically vulcanize A butyl rubber/polyamide thermoplastic vulcanizate is obtained. The TPV was pressed into a 2mm thick sheet according to the standard and the performance was tested. The performance is shown in Table 1.

Example 4:

The basic composition and mass parts of the selected raw materials are as follows:

Wherein the basic composition and mass ratio of self-made compatibilizer are:

Halogen-free butyl rubber 100

Acrylic anhydride 10

Dibenzoyl peroxide 0.01

According to the above formula, first melt and mix the halogen-free butyl rubber, acrylic anhydride, and dibenzoyl peroxide in a Haake internal mixer at 210°C for 15 minutes to obtain graft-modified halogen-free butyl rubber; then bake Mix dry polyamide 12 and halogen-free butyl rubber at 180°C, add graft-modified halogen-free butyl rubber and antioxidants in proportion, wait for the mixture to be uniform and discharge the material to cool to room temperature; Mix with anti-aging agent, plasticizer, vulcanizing agent and vulcanization aid to obtain rubber and plastic premix; put the rubber and plastic premix in the screw extruder, set the vulcanization temperature to 200°C, and the speed to 700rpm, and dynamically vulcanize A butyl rubber/polyamide thermoplastic vulcanizate is obtained. The TPV was pressed into a 2mm thick sheet according to the standard and the performance was tested. The performance is shown in Table 1.

Example 5:

The basic composition and mass parts of the selected raw materials are as follows:

Wherein the basic composition and mass ratio of self-made compatibilizer are:

Chlorobutyl rubber 100

Glycidyl methacrylate 15

Dibenzoyl peroxide 5

According to the above formula, chlorinated butyl rubber, glycidyl methacrylate, and dibenzoyl peroxide were melted and mixed for 3 minutes in a Haake internal mixer at 230°C to obtain graft-modified chlorobutyl rubber. Rubber; then mix the dried polyamide 1010 with chlorobutyl rubber at 185°C, add grafted modified chlorinated butyl rubber and antioxidants in proportion, wait until the mixture is uniform, and then discharge and cool to room temperature ; Then mix it with anti-aging agent, plasticizer, vulcanizing agent and vulcanization aid at room temperature to obtain a rubber-plastic premix; place the rubber-plastic premix in a screw extruder, set the vulcanization temperature to 185°C, and the rotation speed 600rpm, dynamic vulcanization to obtain butyl rubber/polyamide thermoplastic vulcanizate. The TPV was pressed into a 2mm thick sheet according to the standard and the performance was tested. The performance is shown in Table 1.

Embodiment 6:

The basic composition and mass parts of the selected raw materials are as follows:

Wherein the basic composition and mass ratio of self-made compatibilizer are:

Bromobutyl rubber 100

1,2-Epoxybutene 20

Dibenzoyl peroxide 1

According to the above formula, first melt and mix bromobutyl rubber, 1,2-epoxybutene, and dibenzoyl peroxide in a Haake internal mixer at 200°C for 20 minutes to obtain graft-modified butyl bromide base rubber; then mix the dried polyamide 1212 with bromobutyl rubber at 195°C, add graft-modified bromobutyl rubber and antioxidants in proportion, and wait until the mixture is uniform and then discharge and cool to room temperature; then mix it with anti-aging agent, plasticizer, vulcanizing agent and vulcanization aid at room temperature to obtain a rubber-plastic premix; put the rubber-plastic premix in a screw extruder, set the vulcanization temperature to 180°C, The rotating speed is 500rpm, and the butyl rubber/polyamide thermoplastic vulcanizate is obtained through dynamic vulcanization. The TPV was pressed into a 2mm thick sheet according to the standard and the performance was tested. The performance is shown in Table 1.

Table 1 The performance comparison of the embodiment of the present invention and comparative example

In the above table 1 comparison, Comparative Examples 1 and 2 correspond to Examples 1 and 2 respectively, and Comparative Example 1 does not add compatibilizer (difunctional compound grafted modified butyl rubber) compared with Example 1. Comparative Example 2 Compared with Example 2 without adding compatibilizer, the results show that after adding compatibilizer, the physical and mechanical properties and air tightness of butyl rubber/polyamide thermoplastic vulcanizate all become better, the hardness decreases, and the surface becomes smooth, which illustrates the present invention The self-made compatibilizer used has better compatibilizing effect.

The product made by adopting the technology in the patent CN 103030895 A has the best performance among the existing products. Through comparison, we find that the products (embodiments 2-6) prepared by the technology of the present invention are relatively excellent in tensile strength and elongation at break, have lower hardness and significant air-tightness advantages (low air permeability coefficient) ).

Claims (5)

1. A reactive compatibilization butyl rubber/polyamide thermoplastic vulcanizate, its basic composition and mass parts are: The self-made compatibilizer is butyl rubber grafted with a difunctional compound under the action of a free radical initiator, and the mass ratio of butyl rubber, difunctional compound and free radical initiator is 100:0.01-20:0.01-5 ; The bifunctional compound is glycidyl methacrylate, 1,2-epoxybutene or acrylic anhydride; the free radical initiator is dicumyl peroxide or dibenzoyl peroxide; The self-made compatibilizer is prepared by the following method: melt and mix butyl rubber, bifunctional compound, and free radical initiator at 150°C-230°C for 3-20 minutes to obtain graft-modified butyl rubber self-made Compatibilizer. 2. The reactive compatibilization butyl rubber/polyamide thermoplastic vulcanizate according to claim 1, wherein said butyl rubber is halogen-free butyl rubber, chlorinated butyl rubber or brominated butyl rubber rubber. 3. The reactive compatibilized butyl rubber/polyamide thermoplastic vulcanizate according to claim 1, wherein said polyamide is selected from polyamide 1010, polyamide 12 or polyamide 1212. 4. reactive compatibilization butyl rubber/polyamide thermoplastic vulcanizate according to claim 1, is characterized in that, described antioxidant is hindered phenolic antioxidant 1010; Antiaging agent is 2,2,4 - trimethyl-1,2-dihydroquinoline polymer; plasticizer is paraffin oil; vulcanizing agent is zinc oxide; vulcanization assistant is N,N'-m-phenylene bismaleimide. 5. a preparation method of reactive compatibilization butyl rubber/polyamide thermoplastic vulcanizate as claimed in claim 1, the concrete steps are: (1) Melt and mix butyl rubber, bifunctional compound, and free radical initiator at 150°C to 230°C for 3 to 20 minutes to obtain a graft-modified butyl rubber self-made compatibilizer; (2) Rubber and plastic premixing: mix polyamide and butyl rubber at 180°C to 210°C, add antioxidant and self-made compatibilizer obtained in step (1) in proportion, and discharge and cool to Room temperature; then mix with antioxidant, plasticizer, vulcanizing agent and vulcanization aid at room temperature to obtain a rubber-plastic premix; (3) Dynamic vulcanization: Put the rubber-plastic premix obtained in step (2) in a screw extruder, set the screw temperature at 180°C to 210°C, and the rotation speed at 300 to 700rpm, and dynamically vulcanize to obtain reactive compatibilized butyl rubber / Polyamide thermoplastic vulcanizate.