Research The Performance Of High Molecular Weight Polyisobutylene And It’s Blends With Butyl Rubber

High molecular weight polyisobutylene is a highly saturated rubbery polymer. Because of its structure and the side-chain saturated chain methyl-intensive, high molecular weight polyisobutylene has good corrosion resistance, ozone resistance, UV aging resistance, excellent electrical insulation, air tightness and excellent damping properties. But precisely because of its highly saturated structure that it can not be vulcanized by the vulcanization of rubber vulcanization system, limiting its scope of application. In this paper, Di-t-butylperoxy/sulfur vulcanization was used to vulcanize the high molecular weight polyisobutylene. Mechanical properties of the vulcanized rubber is meet the requirements. Blend is the most commonly used method for modifying a rubber, blending compatibility of the two phases affect the final quality of the performance of the material. Moreover butyl rubber and high molecular weight polyisobutylene blends were made. Because of their molecular structure are highly similar, the blends can achieve thermodynamic compatibility in theory, to achieve co-vulcanization, and then expand the application of high molecular weight polyisobutylene.Firstly, comparison of high molecular weight polyisobutylene and butyl rubber on basic performance was made. The high molecular weight polyisobutylene vulcanizate was made. The results showed that:high weight polyisobutylene is highly saturated polymer without unparalleled bond in FT-IR spectra. It’s Tg and thermal stability is basically the same with IIR. High molecular weight polyisobutylene has low Mooney viscosity with good processing properties. With di-t-butylperoxy 8 parts, 4 parts of sulfur as a vulcanization system, High molecular weight polyisobutylene vulcanized rubber was made. It’s tensile strength is 13.99MPa, tear strength is 46.41N /mm, elongation at break is 911%, rebound is 7.82%, compression set is 6.26%, hardness is 41 and 300% elongation is 1.06 MPa. High molecular weight polyisobutylene has excellent acid corrosion resistance and ozone-aging properties. Surface morphology of the sample was basically unchanged after 7 days immersion in concentrated nitric acid and 144h,200 PPHM ozone aging. Tanδmax is 0.944, effective damping temperature range (tanδ>0.3) is 88℃, high molecular weight polyisobutylene has good damping properties.Secondly, the high molecular weight polyisobutylene and butyl rubber was blended. The blend have a good compatibility but two quite different intersection linking density. Studies have shown that:high molecular weight polyisobutylene has a toughening effect to butyl rubber, the largest increases of tensile strength, tear strength, elongation at break are 44%,445%,100%; the biggest drop of 300% modulus and hardness are 45%,14%. Toughening effect is related with the amount and molecular weigh of high molecular weight polyisobutylene. The biggest drop of the blend’s compression set and rebound is 45%,14%. High molecular weight polyisobutylene can also improve the damping properties of butyl rubber, the biggest increase in the loss modulus, loss factor, effective damping temperature range was 24%,10%,19%.The study found that,In addition, high molecular weight polyisobutylene can make cross-link density of vulcanized rubber decreased significantly. High molecular weight polyisobutylene has an adverse effect on hot air aging of butyl rubber.