Study On Structure And Properties Of Chloroprene Rubber/Butadiene Rubber Blends

Chloroprene Rubber (CR) is an important variety among the synthetic rubber. CR has good mechanical, heat-resistant and erodes resistant properties, and applies in many fields. It is one of the most widely used rubbers in many areas. However, it cannot be used in some special situation for its inherent advantages, such as the poor low temperature resistant and low electrical insulating properties. So, how to enhance the low temperature resistance and electrical insulation properties of CR has become a focus among the researchers.In this study, the CR with low temperature resistance and high electrical insulation was prepared by blending Butadiene Rubber (BR) and adding plasticizing agent. And the CR/BR blend was also prepared through blending process. SEM, phase contrast optical microscopy, DMA were used to prove the phase structure of the blends. The effect of the content of BR, silica and DOS on the structure and properties of CR/BR blend were investigated by low temperature resistance, mechanical and electrical insulating properties tests.The results showed that the fracture surfaces of the blend vulcanizate of CR/BR were not smooth with the increase of BR content. Compared with no ZnO vulcanizing system without ZnO, the fracture surfaces of the blend vulcanizate was compact and smooth by using the vulcanizing system with ZnO. The results of phase contrast microscopy showed that when the ratio of CR and BR was 75/25, the two phases were both continuous. The results of DMA indicated that the two rubbers were partly compatible with each other. Whether or not filling silica, the tensile strength and elongation at break of the vulcanized rubber reduced as the increase of BR. However, theρv andρs went up as the increase of BR, but the trend was different.Low temperature resistant and high electrical insulated CR was prepared by blending BR and adding plasticizing agent. The properties of the blend vulcanizate were as follows: Tb less than -55℃; tensile strength 13MPa, elongation at break 510%,ρv 2.8×10¹³Î©Â·cm,ρs 6.2×10¹⁴Ω. With the BR content increasing, the mechanical properties of the vulcanizate dropped down, but the electrical insulation increased. As the content of the silica grew, the electrical insulation and shore hardness increased. And when the content of silica is 30-40phr, the tensile strength and elongation at break of the vulcanizate reached the maximum values. Adding plasticizing agent is in favor of lowering the Tb of the blend vulcanizate, but the mechanical and the electrical insulating properties decrease, respectively.