阅读说明：本技术 一种环保型橡胶填充剂及其制备方法 (Environment-friendly rubber filler and preparation method thereof ) 是由 回军 孙浩程 刘春阳 李宝忠 王宜迪 于 2019-10-30 设计创作，主要内容包括：本发明公开了一种环保型橡胶填充剂及其制备方法,所述橡胶填充剂包括改性粉状固体物、炭黑、硫化剂、活化剂、助硫化剂、硫化促进剂和防老剂。所述环保型橡胶填充剂的制备方法是将改性粉状固体物、炭黑、硫化剂、交联剂、助硫化剂、硫化促进剂、防老剂按比例混合均匀。本发明利用含油固体物经过处理后得到的粉状固体物代替现有橡胶填充剂中使用的矿粉,不仅可以改善和增强橡胶性能,还解决含油固体物带来的环境污染问题,实现其资源化处理和利用,具有显著的经济效益和社会效益。(The invention discloses an environment-friendly rubber filler and a preparation method thereof. The preparation method of the environment-friendly rubber filler is that the modified powdery solid, the carbon black, the vulcanizing agent, the cross-linking agent, the co-vulcanizing agent, the vulcanization accelerator and the anti-aging agent are uniformly mixed in proportion. The invention replaces the mineral powder used in the existing rubber filler with the powdery solid obtained by processing the oily solid, not only can improve and enhance the rubber performance, but also solves the problem of environmental pollution caused by the oily solid, realizes the resource treatment and utilization, and has remarkable economic and social benefits.)

1. An environmentally friendly rubber filler comprising:

modified powdery solid matter: 55wt% -80 wt%;

carbon black: 14wt% -25 wt%;

vulcanizing agent: 1.5wt% -6 wt%;

activating agent: 1.5wt% -6 wt%;

auxiliary vulcanizing agent: 1wt% -3 wt%;

vulcanization accelerator (b): 1wt% -3 wt%;

an anti-aging agent: 1wt% -2 wt%;

wherein the modified powdery solid is prepared by the following method:

(1) dehydrating the oily solid raw material, mixing with a pretreating agent, and performing solid-liquid separation after uniform mixing;

(2) mixing the solid-phase material obtained by separation in the step (1) with a treating agent, reacting, and carrying out solid-liquid separation on a reaction product;

(3) contacting the solid-phase material obtained by the separation in the step (2) with water vapor for treatment;

(4) and (4) mixing the material obtained in the step (3) with a modifier, and uniformly mixing to obtain a modified powdery solid, wherein the modifier is a titanate coupling agent or a silicic acid coupling agent.

2. The environmentally friendly rubber filler according to claim 1, wherein: the raw material of the oil-containing solid is the oil-containing solid generated in the oil exploitation and processing process, and specifically is one or more of homogeneous tank bottom mud at the bottom of an oil separation tank, floating slag in an air flotation tank, residual activated sludge in a biochemical tank, drilling waste liquid generated in an oil exploitation field, oil-polluted soil and tank bottom oil sludge generated in the storage and transportation process.

3. The environmentally friendly rubber filler according to claim 1, wherein: the pretreating agent in the step (1) is one or more of petroleum ether, gasoline, aviation kerosene, light diesel oil and light dirty oil recovered in the oily sewage treatment process.

4. The environmentally friendly rubber filler according to claim 1, wherein: the treating agent in the step (2) is one or more of diesel oil, wax oil and heavy dirty oil obtained after oily sewage treatment.

5. The environmentally friendly rubber filler according to claim 1, wherein: and (2) in the step (1), the dehydration treatment is to reduce the water content of the solid material to be less than 75 wt%.

6. The environmentally friendly rubber filler according to claim 1, wherein: the reaction conditions in the step (2): the reaction pressure is normal pressure, the reaction temperature is 100-180 ℃, and the preferable temperature is 110-125 ℃.

7. The environmentally friendly rubber filler according to claim 1, wherein: the treatment condition in the step (3) is that the treatment is carried out for 0.5 to 3.0 hours at the temperature of between 100 and 140 ℃.

8. The environmentally friendly rubber filler according to claim 1, wherein: the mass ratio of the modifier in the step (4) to the material obtained in the step (3) is 1-2.5: 100.

9. the environmentally friendly rubber filler according to claim 1, wherein: the water content of the modified powdery solid obtained in the step (4) is less than 0.5wt%, and the oil content is 0.1-10 wt%.

10. The environmentally friendly rubber filler according to claim 1, wherein: the vulcanizing agent is one or more of benzoyl peroxide and sulfur, and is preferably benzoyl peroxide.

11. The environmentally friendly rubber filler according to claim 1, wherein: the activating agent is one or more of zinc oxide, magnesium oxide and lead oxide, and zinc oxide is preferred.

12. The environmentally friendly rubber filler according to claim 1, wherein: the auxiliary vulcanizing agent is one or more of stearic acid and N' -m-phenylene bismaleimide.

13. The environmentally friendly rubber filler according to claim 1, wherein: the vulcanization accelerator is one or more of 2-mercaptobenzothiazole, N-tertiary butyl-2-benzothiazole sulfonamide, N' -di-o-tolylguanidine and thiuram, and the thiuram is one or more of thiuram monosulfide, thiuram disulfide and thiuram polysulfide.

14. The environmentally friendly rubber filler according to claim 1, wherein: the anti-aging agent is one or more of N-cyclohexyl-N ' -phenyl-p-phenylenediamine, N- (1, 3-dimethyl) butyl-N ' -phenyl-p-phenylenediamine and N, N ' -diphenyl-p-phenylenediamine.

15. The process for preparing environment-friendly rubber filler as defined in any one of claims 1 to 14, wherein the rubber filler is obtained by mixing the modified powdery solid, carbon black, a vulcanizing agent, a crosslinking agent, a co-vulcanizing agent, a vulcanization accelerator and an anti-aging agent in a proportion and uniformly mixing.

Technical Field

The invention belongs to the technical field of environmental protection, and particularly relates to an environment-friendly rubber filler, and a preparation method and application thereof.

Background

As a reproducible natural polymer material with excellent comprehensive performance, the natural rubber has the advantages of high strength, elasticity, insulating property, good wear resistance and the like, is widely applied to the industries of aerospace, national defense and military industry, automobile industry, medical treatment and health and the like, and plays a very important role in industrial production and national life. The filler is a main auxiliary agent of the rubber and can endow the rubber with a plurality of excellent properties. The powder (particle) filler is still the filler commonly used at present, and the function of the powder (particle) filler is to improve the hardness and mechanical properties of rubber products such as tensile strength, stress at definite elongation and the like; meanwhile, the process performance can be improved and the cost can be reduced.

The traditional fillers are carbon black and white carbon black. Carbon black was the earliest rubber filler (1912) found to have a reinforcing effect. Since its discovery, carbon black has gradually become an indispensable raw material for the rubber industry. The amount of carbon black used is generally 40% to 50% of the rubber consumption, i.e., generally 1 part of carbon black is used for every 2 parts of rubber in the rubber formulation. The white carbon black is a general term of white powdery X-ray amorphous silicic acid and silicate products, mainly refers to precipitated silica, fumed silica and ultrafine silica gel, and also comprises powdery synthetic aluminum silicate, calcium silicate and the like, and the white carbon black has higher cost performance than the carbon black, not only can keep the elasticity and the insulating property of a natural product, but also can greatly improve the strength of the natural rubber product.

However, since the price of carbon black is more than 6000 yuan/ton and the price of white carbon black is more than 4000 yuan/ton, the adoption of low-production energy consumption and low-price natural minerals for rubber products is always the main trend of developing rubber fillers, and the natural inorganic minerals represented by calcium carbonate and pottery clay have low price and respectively show unique performances after processing and treatment, thereby receiving wide attention.

A large amount of oil-containing solids are generated in the processes of petroleum processing and exploitation, the main components of the solids are oil, water and solids, the solids contain various toxic and harmful substances, the substances have great harm to the environment, and the substances are classified as dangerous wastes at home and abroad. Whether the outsourcing treatment or the self-treatment brings heavy burden to enterprises, and the realization of resource treatment for finding a proper way for the substances is a problem which is urgently needed to be solved at present.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides an environment-friendly rubber filler and a preparation method thereof. In the preparation method of the rubber filler, the powdered solid obtained by processing the oily solid is used for replacing mineral powder used in the existing rubber filler, so that the rubber performance can be improved and enhanced, the problem of environmental pollution caused by the oily solid is solved, the resource treatment and utilization are realized, and the preparation method has obvious economic benefit and social benefit.

The first aspect of the present invention provides an environment-friendly rubber filler, comprising:

modified powdery solid matter: 55wt% -80 wt%;

carbon black: 14wt% -25 wt%;

vulcanizing agent: 1.5wt% -6 wt%;

activating agent: 1.5wt% -6 wt%;

auxiliary vulcanizing agent: 1wt% -3 wt%;

vulcanization accelerator (b): 1wt% -3 wt%;

an anti-aging agent: 1wt% -2 wt%.

In the environment-friendly rubber filler, the modified powdery solid is prepared by the following method:

(1) dehydrating the oily solid raw material, mixing with a pretreating agent, and performing solid-liquid separation after uniform mixing;

(2) mixing the solid-phase material obtained by separation in the step (1) with a treating agent, reacting, and carrying out solid-liquid separation on a reaction product;

(3) contacting the solid-phase material obtained by the separation in the step (2) with water vapor for treatment;

(4) and (4) mixing the material obtained in the step (3) with a modifier, and uniformly mixing to obtain a modified powdery solid, wherein the modifier is a titanate coupling agent or a silicic acid coupling agent.

In the method, the oily solid raw material can be an oily solid generated in the oil exploitation and processing process, and specifically can be one or more of homogeneous tank bottom mud at the bottom of an oil separation tank, floating slag in an air flotation tank, residual activated sludge in a biochemical tank, drilling waste liquid generated in an oil exploitation field, oil-polluted soil and tank bottom oil sludge generated in the storage and transportation process.

In the method, the pretreating agent in the step (1) is one or more of petroleum ether, gasoline, aviation kerosene and light dirty oil recovered in the oily sewage treatment process, wherein the final boiling point of the light dirty oil recovered in the oily sewage treatment process is not higher than 250 ℃. The dosage of the pretreating agent is 1-4 times of the weight of the oily solid raw material.

In the method, the treating agent in the step (2) is one or more of diesel oil, wax oil and heavy dirty oil obtained after oily sewage treatment, and the distillation range of the treating agent is 300-800 ℃, and is preferably 350-650 ℃. The dosage of the treating agent is 1-8 times of the weight of the solid-phase material obtained by separation in the step (1).

In the above method, the dehydration treatment in step (1) is to reduce the water content of the solid-containing material to less than 75wt%, and the dehydration treatment may be performed by mechanical dehydration, such as by using a screw stacker.

In the above method, the solid-liquid separation in step (1) may be performed by a static separation or a centrifugal separation.

In the above process, the reaction conditions in step (2): the reaction pressure is normal pressure, the reaction temperature is 100-180 ℃, preferably 110-125 ℃, and the reaction time is 6-12 hours, preferably 8-10 hours.

In the method, the treatment condition in the step (3) is 100-140 ℃ for 0.5-3.0 h.

In the method, the mass ratio of the modifier in the step (4) to the material obtained in the step (3) is 1-2.5: 100.

in the method, the water content of the modified powdery solid obtained in the step (4) is less than 0.5wt%, and the oil content is 0.1-10 wt%.

In the environment-friendly rubber filler, the vulcanizing agent is one or more of benzoyl peroxide and sulfur, and the benzoyl peroxide is preferred.

In the environment-friendly rubber filler, the activating agent is one or more of zinc oxide, magnesium oxide and lead oxide, and zinc oxide is preferred.

In the environment-friendly rubber filler, the auxiliary vulcanizing agent is one or more of stearic acid and N' -m-phenylene bismaleimide.

In the environment-friendly rubber filler, the vulcanization accelerator is one or more of 2-mercaptobenzothiazole, N-tert-butyl-2-benzothiazole sulfonamide, N' -di-o-tolylguanidine and thiuram, and the thiuram is one or more of thiuram monosulfide, thiuram disulfide and thiuram polysulfide.

In the environment-friendly rubber filler, the anti-aging agent is one or more of N-cyclohexyl-N ' -phenyl-p-phenylenediamine, N- (1, 3-dimethyl) butyl-N ' -phenyl-p-phenylenediamine and N, N ' -diphenyl-p-phenylenediamine.

The second aspect of the invention provides a preparation method of an environment-friendly rubber filler, which comprises the steps of mixing modified powdery solid, carbon black, a vulcanizing agent, a cross-linking agent, an auxiliary vulcanizing agent, a vulcanization accelerator and an anti-aging agent in proportion, and uniformly mixing to obtain the rubber filler.

Compared with the prior art, the environment-friendly rubber filler and the preparation method thereof provided by the invention have the following advantages:

(1) in the environment-friendly rubber filler provided by the invention, the lipophilicity of the modified powdery solid obtained by dehydrating, pretreating, treating, performing steam treatment and modifying the oily solid raw material is greatly improved, the modified powdery solid is more favorable for rolling when being used as the filler in rubber production, and the appropriate oil content in the modified powdery material is controlled, wherein the oily component can play a role of a softener and a plasticizer, so that the wetting capacity of the filler is improved, the filler is uniformly dispersed, the quality of a rubber product can be improved, the problem of environmental pollution caused by the treatment of the existing oily solid material is solved, the resource treatment and utilization are realized, and the concept of circular economy is met.

(2) According to the environment-friendly rubber filler provided by the invention, the modified subpackaged solid is adopted, and the modified subpackaged solid belongs to a soil-in-oil structure, so that when the modified subpackaged solid is used as a rubber filler component, the modified subpackaged solid is beneficial to filling and embedding into gaps of mixed materials, the interaction force between the mixed materials is enhanced, the mixed materials are more compact, and the material strength of the rubber filler is increased.

(3) The rubber filler provided by the invention is simple in preparation method, low in production cost, environment-friendly and environment-friendly.

Detailed Description

The following examples and comparative examples are given to illustrate the environmentally friendly rubber filler of the present invention and the preparation method thereof, but the present invention is not limited thereto.

The oily solid raw materials utilized in the examples are from tank bottom sludge and scum of a certain refinery company, and the basic properties are as follows:

composition of	Water (W)	Oil	Solid body
				Raw material A: storage tank bottom mud	32.4wt%	45.1wt%	22.5wt%
Raw material B: dross	92.8wt%	2.7wt%	5.5wt%

Example 1

The rubber filler comprises the following components in percentage by mass:

modified powdery solid matter: 74 wt.%

Carbon black: 17 wt%;

benzoyl peroxide: 2 wt%;

zinc oxide: 2 wt%%;

stearic acid: 1 wt%;

n' -m-phenylenebismaleimide: 1 wt%.

2-mercaptobenzothiazole: 1.4 wt%;

n, N' -di-o-tolylguanidine: 0.6 wt%.

N-cyclohexyl-N' -phenyl-p-phenylenediamine: 1 wt.%

The modified powdery solid in this example was prepared as follows: sending the scum of the oily solid raw material B into a screw stacking machine for mechanical dehydration until the water content is reduced to 73.7 wt%; and (3) conveying the dehydrated oily solid into a pretreatment tank, fully mixing the oily solid with a pretreatment agent, wherein the dosage of the pretreatment agent is 3.5 times that of the oily solid, and standing or centrifuging to realize solid-liquid separation. The solid phase material obtained by separation enters a treatment tank to be fully mixed with a treatment agent, the dosage of the treatment agent is 5 times of that of the solid phase material obtained by separation, the treatment is carried out under the conditions of normal pressure and 120 ℃, the treatment time is 10 hours, oil and solids in the solid phase material are transferred into the treatment agent, the liquid phase is recycled after solid-liquid separation, solid precipitates are contacted with water vapor and are carried out under the conditions of normal pressure and 105 ℃, the treatment time is 2.5 hours, the powdery solid obtained after treatment and a modifier titanate coupling agent are stirred by a sealed stirrer and are fully mixed to obtain the composite material, and the mass ratio of the modifier to the powdery solid is 2.5: 100. wherein the used pretreating agent is aviation kerosene, the used treating agent is diesel oil, the distillation range is 300-400 ℃, the water content of the obtained powdery solid is 0.39wt%, and the oil content is 2.7 wt%.

Example 2

The rubber filler comprises the following components in percentage by mass:

modified powdery solid matter: 77% by weight

Carbon black: 13.5 wt%;

benzoyl peroxide: 1.5 wt%;

zinc oxide: 3 wt%%;

stearic acid: 1.5 wt%;

2-mercaptobenzothiazole: 1.3 wt%;

thiuram disulfide: 0.2 wt%;

n- (1, 3-dimethyl) butyl-N' -phenyl-p-phenylenediamine: 2 wt%.

The modified powdery solid in this example was prepared as follows: sending the scum of the oily solid raw material B into a screw stacking machine for mechanical dehydration until the water content is reduced to 71.5 wt%; sending the dehydrated oil-containing solid into a pretreatment tank, fully mixing the oil-containing solid with a pretreatment agent, wherein the dosage of the pretreatment agent is 2 times of that of the oil-containing solid, standing or centrifuging the oil-containing solid to realize solid-liquid separation, feeding the separated solid-phase material into a treatment tank to be fully mixed with the treatment agent, wherein the dosage of the treatment agent is 4 times of that of the separated solid-phase material, treating the solid-phase material at normal pressure and 125 ℃ for 8 hours, transferring oil and solid of the solid-phase material into the treatment agent, performing solid-liquid separation, recycling the liquid phase, contacting the solid precipitate with steam at normal pressure and 100 ℃, treating the solid precipitate for 1 hour, stirring the treated powdery solid and a modifier titanate coupling agent by a sealed stirrer, and fully mixing the powdery solid and the powdery solid, wherein the mass ratio of the modifier to the powdery solid is 1: 100. wherein the used pretreating agent is petroleum ether, the used treating agent is wax oil, the distillation range is 350-500 ℃, the water content of the obtained powdery solid is 0.33wt%, and the oil content is 8.9 wt%.

Example 3

The rubber filler comprises the following components in percentage by mass:

modified powdery solid matter: 70 wt.%

Carbon black: 20 wt%;

benzoyl peroxide: 2.5 wt%;

zinc oxide: 1.5 wt%;

n' -m-phenylenebismaleimide: 3 wt%;

n-tert-butyl-2-benzothiazolesulfenamide: 1.8 wt%;

thiuram monosulfide: 0.2 wt%;

n, N' -diphenyl-p-phenylenediamine: 1 wt%.

The modified powdery solid in this example was prepared as follows: sending the oily solid raw material (the raw material A and the raw material B are mixed according to the weight ratio of 1: 10) into a screw stacking machine for mechanical dehydration until the water content is reduced to 68.2 wt%; sending the dehydrated oil-containing solid into a pretreatment tank, fully mixing the oil-containing solid with a pretreatment agent, wherein the dosage of the pretreatment agent is 4 times of that of the oil-containing solid, standing or centrifuging the oil-containing solid to realize solid-liquid separation, feeding the solid-phase material obtained by solid-liquid separation into a treatment tank, fully mixing the solid-phase material with the treatment agent, wherein the dosage of the treatment agent is 6 times of that of the solid-phase material obtained by separation, treating the solid-phase material at normal pressure and 115 ℃ for 9 hours, transferring oil and solid in the solid-phase material into the treatment agent, performing solid-liquid separation, recycling the liquid phase, contacting the solid precipitate with steam at normal pressure and 140 ℃, treating the solid for 1 hour, stirring the treated powdery solid and a modifier titanate coupling agent by a sealed stirrer, and fully mixing the powdery solid to obtain the modifier titanate coupling agent, wherein the mass ratio of the modifier: 100. wherein the pretreating agent is gasoline, the treating agent is heavy dirty oil obtained after the oily sewage is treated, the distillation range is 500-650 ℃, and the water content of the obtained powdery solid is 0.24wt% and the oil content is 5.6 wt%.

Example 4

The rubber filler comprises the following components in percentage by mass:

modified powdery solid matter: 60 wt.%

Carbon black: 25 wt%;

benzoyl peroxide: 5 wt%;

zinc oxide: 4 wt%;

stearic acid: 3 wt%;

2-mercaptobenzothiazole: 1.3 wt%;

n, N' -di-o-tolylguanidine: 1.7 wt%.

N- (1, 3-dimethyl) butyl-N' -phenyl-p-phenylenediamine: 1 wt%.

The modified powdery solid in this example was prepared as follows: sending an oil-containing solid raw material (the raw material A and the raw material B are mixed according to the weight ratio of 1: 5) into a screw stacking machine for mechanical dehydration until the water content is reduced to 70.9 wt%; sending the dehydrated oil-containing solid into a pretreatment tank, fully mixing the oil-containing solid with a pretreatment agent, wherein the dosage of the pretreatment agent is 3 times of that of the oil-containing solid, standing or centrifuging the oil-containing solid to realize solid-liquid separation, feeding the separated solid-phase material into a treatment tank to be fully mixed with a treatment agent, wherein the dosage of the treatment agent is 2 times of that of the separated solid-phase material, treating the solid-phase material at the normal pressure and 117 ℃ for 9.5 hours, transferring oil and solid in the solid-phase material into the treatment agent, performing solid-liquid separation, recycling the liquid phase, contacting the solid precipitate with water vapor at the normal pressure and 135 ℃, treating the solid precipitate for 2.5 hours, stirring the treated powdery solid and a modifier titanate coupling agent by a sealed stirrer, and fully mixing the powdery solid with the modifier titanate coupling agent, wherein the mass ratio of the modifier to the powdery solid is 1.5: 100. the pretreatment agent is light dirty oil obtained after oily sewage treatment, the treatment agent is heavy dirty oil obtained after oily sewage treatment, the distillation range is 600-750 ℃, the water content of the obtained powdery solid is 0.09wt%, and the oil content is 4.9 wt%.

Example 5

The rubber filler comprises the following components in percentage by mass:

modified powdery solid matter: 60 wt.%

Carbon black: 25 wt%;

benzoyl peroxide: 6 wt%;

zinc oxide: 3 wt%%;

n' -m-phenylenebismaleimide: 2 wt%.

N-tert-butyl-2-benzothiazolesulfenamide: 2.4 wt%;

thiuram polysulfide: 0.6 wt%;

n- (1, 3-dimethyl) butyl-N' -phenyl-p-phenylenediamine: 1 wt%;

the preparation of the powdery solid in this example was as follows: sending the scum of the oily solid raw material B into a screw stacking machine for mechanical dehydration until the water content is reduced by 71.1 wt%; sending the dehydrated oil-containing solid into a pretreatment tank, fully mixing the oil-containing solid with a pretreatment agent, wherein the dosage of the pretreatment agent is 2.5 times of that of the oil-containing solid, standing or centrifuging the mixture to realize solid-liquid separation, feeding the separated solid-phase material into a treatment tank to be fully mixed with the treatment agent, the dosage of the treatment agent is 3 times of that of the separated solid-phase material, treating the solid-phase material at the normal pressure and at the temperature of 118 ℃ for 10 hours, transferring oil and solid in the separated solid-phase material into the treatment agent, performing solid-liquid separation, recycling the liquid phase, contacting the solid precipitate with water vapor at the normal pressure and at the temperature of 135 ℃, treating the solid for 2 hours, stirring the treated powdery solid and a modifier titanate coupling agent by a sealed stirrer, and fully mixing the powdery solid, wherein the mass ratio of the modifier to the powdery solid is 2: 100. wherein the used pretreating agent is light dirty oil obtained after oily sewage treatment, the used treating agent is wax oil, and the distillation range is 300-450 ℃. The water content of the obtained powdery solid was 0.17wt% and the oil content was 3.1 wt%.

Comparative example 1

The same as in example 1, except that calcium carbonate, which is commonly used in the prior art, was used in place of the modified powdery solid.

Comparative example 2

The same as in example 1 except that no pretreating agent was used in the preparation of the modified powdery solid.

Comparative example 3

The same as in example 1 except that no treating agent was used in the preparation of the modified powdery solid.

Evaluation of the use properties of the rubber filler:

fully grinding the rubber fillers prepared in the examples and the comparative examples to 400 meshes, mixing the rubber fillers with raw rubber according to the mass ratio of 1: 2-3, and mixing and vulcanizing the mixture to obtain synthetic rubber; the mixing temperature is 60 ℃, and the mixing time is 7 min; the vulcanization temperature is 150 ℃, and the vulcanization time is 25 min. The properties of the obtained rubber are shown in Table 1 below.

In the examples and comparative examples of the present invention, the properties of the reclaimed rubber are represented by three indexes, i.e., tensile strength, elongation at break, and shore hardness. Wherein the test is carried out according to Shore hardness GB-T531-1992 Shore A hardness test method for vulcanized rubber, and the tensile strength and the elongation at break are determined according to the method involved in GB/T1701-2001 determination of tensile strength and elongation at break for hard rubber.

TABLE 1 synthetic rubber Properties