| Rubber compound can be divided into functional rubber additives and reinforcing materials, which is an essential part of the rubber products.Traditional rubber compound are mostly powder chemicals, can greatly improve the performance of rubber products and the processing performance of rubber, but there are many problems in the application. First of all, powder additives, because of its own characteristics, in the ingredients and mixing are prone to flying, resulting in measurement is not accurate, while the environment pollution. Second, the fluidity of the rubber auxiliaries will be affected by the microscopic properties of the powder particles. In addition,since some of the inorganic small additives such as sulfur and metal oxides such as zinc oxide and rubber compatibility is poor, resulting in the rubber compound is difficult to disperse and defects evenly in the rubber. Aramid pulp (AP) is an excellent sub-micron reinforced material, it has high modulus,chemical resistance, high temperature resistance, excellent dimensional stability and other characteristics, so that it is widely used in rubber products.However, due to its special fiber structure, leading to the micro-fiber easily intertwined with each other, and aramid pulp electrostatic adsorption is extremely strong, the fiber surface showed significant chemical inertia. These problems lead to the AP in the rubber matrix is difficult to disperse evenly,which ultimately affect the AP reinforcement performance. In view of the above problems, the need for powder and fiber are pretreatment and masterbatch. In this paper, the pretreatment of sulfur powder as an example to study the carrier system components on the rubber additives masterbatch powder dispersion, processing rheology and masterbatch versatility, storage,and then determine the carrier system of the final component. The preparation technology of rubber additives masterbatch was explored, and the optimal formula was applied to the pre-dispersion treatment of organic zinc powder. At the same time, the pretreatment of AP was studied by the synergetic effect of coupling agent in situ modification technique and highly active polyisobutylene osmotic isolation technology. The effects of coupling agent and high activity polyisobutylene resin on the pretreatment of aramid, the mechanism of action in the pulp and the synergistic effect of the two.Firstly, based on the EPDM / EVM carrier system, the effect of EVM and naphthenic oil on the rheological processing performance and powder dispersibility of powder pretreatment granulation was systematically studied.The mechanism of liquid wetting auxiliaries was put forward. Then using liquid ethylene propylene rubber instead of naphthenic oil as liquid wetting agent to optimize the carrier system formula, the rheological properties,powder dispersibility, masterbatch versatility and storage stability after masterbatch optimization were systematically studied, and the optimum formula was obtained.Characterization of the microstructure of organic zinc, at the same time,the feasibility of replacing indirect zinc oxide as low-zinc environment-friendly vulcanization activator was also explored, the pre -dispersion granulation of organic zinc was carried out by using the optimal formula of the carrier system obtained in the above experiment, which further solved the problem that organic zinc was difficult to disperse in the compound.By dry mixing and high agitation, the effects of different active coupling agents on the pretreatment were investigated. The effect of A171 as the best pretreatment coupling agent was studied. The permeation of liquid ethylene propylene rubber was studied, A171 was identified as the best pretreatment coupling agent. The mechanism of seepage and isolation of liquid ethylene propylene rubber, the mechanism of Coupling agent and synergistic was explored. It was found that the AP masterbatch obtained by the treatment with liquid ethylene propylene rubber and coupling agent A171 could improve the interfacial bonding strength of EPDM by co-vulcanization with matrix rubber,in the small deformation the EPDM products modulus enhancement is obvious. |
PDF Full Text Request