Butyl rubber slurry formation: Cold-stage SEM study

Abstract

Poly(isobutylene-co-isoprene) or butyl rubber was invented in 1937 and has been used in many technologically important applications during the ensuing years. Its physical properties such as air-retention encouraged its uses in tire inner tubes, and played an important part in the tubeless tire development. The halogenated derivative is now predominantly used in tubeless radial tires.Butyl rubber is made by a slurry polymerization process with aluminum chloride catalyst at -95°C in methyl chloride diluent. Typical reactor runs only last from 18-60 hours because of fouling of the reactor. Fouling and agglomeration occur because only weak electrostatic repulsion forces exist, but recent patents describe the use of block copolymer stabilizer agents which create steric (entropic) repulsion forces between slurry polymer particles and preventTo better understand the mechanism of reactor fouling, a method was developed to collect samples from within the reactor.