CN104497378A - Anti-cracking high-performance rubber composite material and preparation method thereof - Google Patents

Abstract

The invention provides an anti-cracking high-performance rubber composite material and a preparation method thereof, which comprises the following raw materials in parts by mass: 100 parts of rubber, 1-8 parts of functionalized low molecular weight polymer, 5-30 parts of white carbon black, 1-4 parts of anti-aging agent, 0.5-3 parts of vulcanizing agent, 1-5 parts of vulcanization activator, and 1-3 parts of vulcanization accelerator. The preparation method comprises the following steps: ultrasonically disperse 10-50 parts of white carbon black for 10-50 minutes, then dry in a vacuum drying oven for use, and mix the dried white carbon black with 1-6 parts of functionalized low-molecular-weight polymer Mix in an internal mixer for 10-30 minutes, fully react and blend with rubber in an open mill, and vulcanize the prepared masterbatch in a vulcanizer at 120-160°C for 10-20 minutes to obtain a crack-resistant high-performance rubber composite material. Extended service life, non-toxic, stable, easy to store, safe and environmentally friendly, strong crack resistance.

Description

A kind of anti-cracking high-performance rubber composite material and its preparation method

technical field

The invention relates to the technical field of polymer material processing, in particular to a composite material and a preparation method thereof, in particular to a crack-resistant high-performance rubber composite material and a preparation method thereof.

Background technique

Rubber products, especially tires, will inevitably encounter a series of problems such as aging, cracks, and wear during work. Among them, the growth of cracks is particularly harmful to rubber. Under the action of periodic loads, rubber will gradually produce Fatigue microcracks, as time increases, the cracks gradually expand during the fatigue process, and eventually lead to the destruction of the rubber material, so the growth of rubber cracks is a problem that cannot be ignored. At present, there are mainly the following methods for anti-cracking rubber composite materials: through modified butadiene rubber and tin-modified polybutadiene rubber filled with silica formed by polymerization with lithium initiator (Chinese patent CN101735498A) to strengthen The anti-cracking performance of rubber; the anti-crack growth of natural rubber materials is enhanced by a surface-modified aramid fiber (Chinese patent CN103243561A); the anti-crack growth of rubber composite materials is enhanced by adding wear-resistant expanded graphite (Chinese patent CN103483631A), etc. .

As a cheap filler, carbon black and white carbon black are often used as reinforcing agents for rubber, which greatly reduces the cost of rubber production. Among them, carbon black is the main reinforcing agent for tire production, and for the reinforcement of light-colored products , the most used is white carbon black, white carbon black has super adhesion, low heat generation and other properties, so it can also replace part of carbon black in black rubber products, and more and more attention has been paid to green tires . However, under a similar specific surface area, its reinforcing effect is not as good as that of carbon black, which is due to the large amount of silicon hydroxyl (Si-OH) on its surface making it a highly polar material, and like many commonly used rubbers (NR, SBR... ) is non-polar, so that due to the poor compatibility between the two, the surface of the filler will slide with the rubber molecules under high strain to generate energy dissipation. Usually, the way to solve this problem is to add a silane coupling agent, which builds a bridge between the filler and the rubber through the active functional groups at both ends, enhances the interaction between the silica and the rubber, and improves the silica filling. Properties of non-polar rubber. Chinese patent CN103992437A realizes the control and optimization of the interface structure between the inorganic filler and the matrix material by preparing a new type of silane macromolecular coupling agent. However, because most silane coupling agents have certain toxicity, and are not easy to store (easy to decompose), and because most silane coupling agents have relatively large molecular weights, it takes a long time and a high temperature during the mixing process , where the sulfur bond breaks during high-temperature mixing and participates in the vulcanization reaction, resulting in scorch, which has become a fatal shortcoming of the silane coupling agent. Therefore, it is particularly important to develop a non-toxic and stable rubber reinforcing agent to improve the performance of silica-filled rubber.

In order to make rubber easy to process, liquid oils and fats are often added in the industry to achieve a softening effect, which is more convenient for processing. However, most of these substances contain polycyclic aromatic hydrocarbons, which are harmful to the human body in contact with the skin, and Most of them are polluting and easy to change color in the sun; they are easy to be extracted and migrated in rubber, which greatly reduces their application in rubber. At present, the research on low molecular weight polymers with a structure similar to rubber as softeners has become a hot topic. They can not only give rubber good processing properties, but also have a chain structure similar to rubber. After functionalization, they can significantly improve the relationship between filler and matrix. Compatibility, and can participate in cross-linking during vulcanization, becoming an integral part of the rubber cross-linking network, so that the rubber has excellent physical properties and stability.

Contents of the invention

The technical problem to be solved by the present invention is to provide a kind of anti-cracking high-performance rubber composite material and its preparation method, combining the characteristics of functionalized low molecular weight polymer and silica, allowing the silica with hydroxyl to be grafted onto the On the functionalized low-molecular-weight polymer with carboxyl side chain, and through vulcanization, it enters the cross-linked network structure of the rubber, so that the silica is better dispersed in the rubber, and finally endows the rubber with better crack resistance and stability Good, easy to store, safe and environmentally friendly, long service life, strong crack resistance.

In order to solve the above-mentioned existing technical problems, the present invention adopts the following scheme: a kind of anti-cracking high-performance rubber composite material, comprising the raw materials of the following parts by mass: 100 parts of rubber, 1-8 parts of functionalized low molecular weight polymer , 5-30 parts of white carbon black, 1-4 parts of anti-aging agent, 0.5-3 parts of vulcanizing agent, 1-5 parts of vulcanization activator, and 1-3 parts of vulcanization accelerator.

Preferably, the vulcanizing agent is sulfur.

Preferably, the anti-aging agent is at least one of N-cyclohexyl-N'-phenyl-p-phenylenediamine and N',N'-dicyclohexyl-p-phenylenediamine.

Preferably, the vulcanization activator is zinc oxide and stearic acid.

Preferably, the vulcanization accelerator is one of benzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide, and tetramethylthiuram disulfide.

Preferably, the particle size of the white carbon black is 30-50 nanometers.

Preferably, the functionalized low molecular weight polymer side chains contain carboxyl groups.

In order to achieve the above object, the present invention proposes a method for preparing a crack-resistant high-performance rubber composite material, comprising the following steps: ultrasonically dispersing 10-50 parts of white carbon black for 10-50 minutes, then drying in a vacuum oven for standby use, and The dried white carbon black and 1-6 parts of functionalized low-molecular-weight polymers are kneaded in an internal mixer for 10-30 minutes. After fully reacting, they are mixed with rubber in an open kneader. Vulcanize at 120-160°C for 10-20 minutes to obtain a crack-resistant high-performance rubber composite material.

Beneficial effect:

The present invention adopts the above-mentioned technical scheme to provide a kind of anti-cracking high-performance rubber composite material and its preparation method, which makes up for the deficiencies in the prior art, reduces the stress concentration phenomenon when the rubber is stressed, and slows down the speed of crack growth. Improved rubber crack resistance.

Detailed ways

A high-performance anti-cracking rubber composite material, which is made of the following raw materials in parts by mass: 100 parts of rubber, 1-8 parts of functionalized low molecular weight polymer, 5-30 parts of white carbon black, 1-4 parts of anti-aging agent, 0.5-3 parts of vulcanizing agent, 1-5 parts of vulcanization activator, and 1-3 parts of vulcanization accelerator. The vulcanizing agent is sulfur. The anti-aging agent is at least one of N-cyclohexyl-N'-phenyl-p-phenylenediamine, N',N'-dicyclohexyl-p-phenylenediamine. The vulcanization activator is zinc oxide and stearic acid. The vulcanization accelerator is one of benzothiazole disulfide, N-cyclohexyl-2-benzothiazole sulfenamide and tetramethylthiuram disulfide. The particle size of the white carbon black is 30-50 nanometers. The functionalized low molecular weight polymer side chains contain carboxyl groups.

A method for preparing a crack-resistant high-performance rubber composite material, comprising the following steps: ultrasonically dispersing 10-50 parts of white carbon black for 10-50 minutes, then drying in a vacuum drying oven for use, and mixing the dried white carbon black with functional Mix 1-6 parts of low-molecular-weight polymers in an internal mixer for 10-30 minutes, and mix them with rubber in an open mixer after fully reacting. The prepared masterbatch is vulcanized in a vulcanizer at 120-160°C for 10-20 minutes. The anti-cracking high-performance rubber composite material is obtained.

The functionalized low molecular weight polymer used in the present invention has a side group carboxyl group, as shown in the following formula:

During actual work, the present invention is specifically described by the following examples, it is necessary to point out that this example is only used to further illustrate the present invention, can not be interpreted as limiting the protection scope of the present invention, those skilled in the art in this field Some non-essential improvements and adjustments can be made based on the contents of the present invention described above.

The white carbon black used in the present invention adopts 115GR, and the average particle diameter is about 30-50 nanometers. the

The mixing formula (parts by mass) of the rubber of the present invention is as follows: 100 parts of rubber, 2-5 parts of stearic acid, 2-5 parts of zinc oxide, 1-3 parts of sulfur, and 1-2 parts of accelerator.

Three kinds of samples of the present invention are mixed in the following ratio (mass ratio): natural rubber: functionalized low molecular weight polymer: white carbon black=100:(1-8):(10-50)

The pretreatment of the white carbon black of the present invention: put the white carbon black into a vacuum drying oven to dry for 24-72 hours, ultrasonically disperse it for 15-60 minutes, and put it into a vacuum drying oven for standby.

The grafting reaction of the functionalized low molecular weight polymer and white carbon black of the present invention: mix the rubber and the functionalized low molecular weight polymer and white carbon black in an internal mixer at 140-170° C. for 5-15 minutes, take it out and start the kneading Add accelerator and vulcanizing agent into the vulcanizer, place it for 24-48h, vulcanize at 140-160°C for 5-10min, and then take it out to prepare the sample to be tested.

The performance test of the sample of the present invention: the experiment adopts the crack extension testing instrument produced by Metravib Company of France, and the rubber with the pre-cut is subjected to the cyclic load effect with a frequency of 5-10Hz, and the tearing energy is 1000J/m ² ; Strength, elongation at break, and modulus stress are tested according to GB/T528-199, and hardness (Shore A) is tested according to GB/T23651-2009.

Example 1: Fill 100 parts of styrene-butadiene rubber with 2 parts of functionalized low-molecular-weight polymers and fill 10 parts of white carbon black in an internal mixer at 160 ° C for 15 minutes. After the reaction is complete, add 2 parts of sulfur and accelerator N - 1 part of cyclohexyl-2-benzothiazole sulfenamide, 5 parts of zinc oxide, 2 parts of stearic acid, and mix them completely in an open mill to prepare a masterbatch. 15MPa, molded for 12 minutes, the anti-cracking high-performance rubber composite material was obtained, the tensile strength at break was 12.4MPa, the elongation at break was 520%, the crack growth rate was 90nm/cycle, and the hardness (Shore A) was 62.2 degrees. See Table 1 for details.

Example 2: 100 parts of natural rubber and 2 parts of functionalized low-molecular-weight polymers are filled with 10 parts of white carbon black and blended in an internal mixer at 160 ° C for 15 minutes. After the reaction is complete, 2 parts of sulfur are added, and the accelerator N- 1 part of cyclohexyl-2-benzothiazole sulfenamide, 5 parts of zinc oxide, and 2 parts of stearic acid are mixed completely in an open mill to prepare a masterbatch. The masterbatch is made of a flat vulcanizer at 150°C and a pressure of 15MPa , molded for 12 minutes, and the anti-cracking high-performance rubber composite material was obtained. The tensile strength at break was 21.6MPa, the elongation at break was 550%, the crack growth rate was 30nm/cycle, and the hardness (Shore A) was 72.4 degrees. See Table 1.

Example 3: Fill 100 parts of butadiene rubber with 2 parts of functionalized low molecular weight polymer and fill 10 parts of white carbon black in an internal mixer at 160°C for 15 minutes. After the reaction is complete, add 2 parts of sulfur and accelerator N - 1 part of cyclohexyl-2-benzothiazole sulfenamide, 5 parts of zinc oxide, 2 parts of stearic acid, and mix them completely in an open mill to prepare a masterbatch. 15MPa, molded for 12 minutes, the anti-cracking high-performance rubber composite material was obtained, the tensile strength at break was 9.8MPa, the elongation at break was 530%, the crack growth rate was 100nm/cycle, and the hardness (Shore A) was 65.4 degrees. See Table 1 for details.

Table 1: Raw materials and proportioning required for embodiments 1-3

Comparative Example 1: Fill 100 parts of styrene-butadiene rubber with 10 parts of white carbon black and blend in an internal mixer at 160°C for 15 minutes. After the reaction is complete, add 2 parts of sulfur and accelerator N-cyclohexyl-2-benzothiazole 1 part of sulfenamide, 5 parts of zinc oxide, and 2 parts of stearic acid are mixed completely in an open mill to obtain a masterbatch. The masterbatch is molded with a flat vulcanizer at 150°C and a pressure of 15MPa for 12 minutes to obtain an anti-cracking High-performance rubber composite material, the tensile strength at break is 7.1MPa, the elongation at break is 500%, the crack growth rate is 150nm/cycle, and the hardness (Shore A) is 60.7 degrees. See Table 2 for details.

Comparative Example 2: Fill 100 parts of natural rubber with 10 parts of white carbon black and blend in an internal mixer at 160°C for 15 minutes. After the reaction is complete, add 2 parts of sulfur, accelerator N-cyclohexyl-2-benzothiazole times 1 part of sulfonamide, 5 parts of zinc oxide, and 2 parts of stearic acid are mixed completely in an open mill to obtain a masterbatch. The masterbatch is molded with a flat vulcanizer at 150°C and a pressure of 15MPa for 12 minutes to obtain a crack-resistant high Performance rubber composite material, the tensile strength at break is 15.1MPa, the elongation at break is 530%, the crack growth rate is 70nm/cycle, and the hardness (Shore A) is 74.2 degrees. See Table 2 for details.

Comparative Example 3: Fill 100 parts of butadiene rubber with 10 parts of white carbon black and blend in an internal mixer at 160°C for 15 minutes. After the reaction is complete, add 2 parts of sulfur, accelerator N-cyclohexyl-2-benzothiazole 1 part of sulfenamide, 5 parts of zinc oxide, and 2 parts of stearic acid are mixed completely in an open mill to obtain a masterbatch. The masterbatch is molded with a flat vulcanizer at 150°C and a pressure of 15MPa for 12 minutes to obtain an anti-cracking High-performance rubber composite material, the tensile strength at break is 5.2MPa, the elongation at break is 500%, the crack growth rate is 160nm/cycle, and the hardness (Shore A) is 67.4 degrees. See Table 2 for details.

Table 2: Raw materials and proportioning required for comparative example 1-3

Table 3: Example 1-3 and comparative example 1-3 sample performance comparison

The specific embodiments described herein are only examples to illustrate the spirit of the present invention, and those skilled in the art to which the present invention belongs can make various modifications or supplements to the described specific embodiments or replace them in similar ways, but It does not depart from the spirit of the invention or go beyond the scope defined by the appended claims.

Claims (8)

1. a cracking resistance high-performance rubber matrix material, is characterized in that: the raw material comprising following masses part is made: rubber 100 parts, functionalized low-molecular weight polymer 1-8 part, white carbon black 5-30 part, anti-aging agent 1-4 part, vulcanizing agent 0.5-3 part, vulcanization activator 1-5 part, vulcanization accelerator 1-3 part.

2. a kind of cracking resistance high-performance rubber matrix material according to claim 1, is characterized in that: described vulcanizing agent is sulphur.

3. a kind of cracking resistance high-performance rubber matrix material according to claim 1, is characterized in that: described anti-aging agent is N-cyclohexyl-N '-diphenyl-para-phenylene diamine, N ', N ' at least one in-dicyclohexyl Ursol D.

4. a kind of cracking resistance high-performance rubber matrix material according to claim 1, is characterized in that: described vulcanization activator is zinc oxide and stearic acid.

5. a kind of cracking resistance high-performance rubber matrix material according to claim 1, is characterized in that: described vulcanization accelerator is benzothiazyl disulfide, N cyclohexyl 2 benzothiazole sulfenamide, the wherein one in tetramethyl-thiuram disulfide three kinds.

6. a kind of cracking resistance high-performance rubber matrix material according to claim 1, is characterized in that: the particle diameter of described white carbon black is 30-50 nanometer.

7. a kind of cracking resistance high-performance rubber matrix material according to claim 1, is characterized in that: described functionalized low-molecular weight polymer side chain contains carboxyl.

8. the preparation method of a cracking resistance high-performance rubber matrix material, it is characterized in that: comprise the following steps: by 10-50 part white carbon black ultrasonic disperse 10-50min, dry for standby in vacuum drying oven again, by the white carbon black of oven dry and functionalized low-molecular weight polymer 1-6 part mixing 10-30min in Banbury mixer, blended in mill with rubber after abundant reaction, obtained masterbatch 120-160 DEG C of sulfuration 10-20min in vulcanizer obtains cracking resistance high-performance rubber matrix material.