Dry modification of coal-measure kaolin and its effect on rubber properties

With the rapid development of the rubber industry, the traditional reinforcing fillers carbon black and silica have been unable to meet the demand, and finding cheap reinforcing fillers has become an important research topic in the industry. Among them, kaolin has become a rubber reinforcing filler with broad application prospects due to its abundant reserves, low price and outstanding reinforcing effect.

Coal measure kaolin refers to kaolinite clay rock with kaolinite as the main mineral component in coal measure strata. The score can reach above 0.97.

To make kaolin show good reinforcement effect in rubber matrix, it is very important to modify its surface. Zhang Qingbin et al. modified the surface of kaolin by high-speed shearing, crushing and stirring, in order to achieve surface organicization and good combination with the rubber matrix. At the same time, they evaluated the modification effect of kaolin. SBR) physical properties and interface bonding, the results show that:

(1) In the high-speed shearing pulverizer, the optimal modification conditions of kaolin are: the mass fraction of modifier (coupling agent KH-550) is 0.04, and the modification time is 1min.

(2) Under the optimal modification conditions, compared with the unmodified kaolin compound, the physical properties of the modified kaolin compound are significantly improved, the tensile strength is increased by 89%, the tear strength is increased by 21%, and the DIN wear amount is reduced. 18% smaller.

(3) Compared with unmodified kaolin, the compatibility of modified kaolin with rubber is improved, and it combines well with the rubber matrix, which is beneficial to transfer stress and make the rubber compound exhibit excellent physical properties.