Advances in butyl rubber synthesis via cationic polymerization: an overview

Abstract

The global market is anticipated to display considerable growth for synthetic rubber because of superior product properties in comparison to natural rubber. The high volatility in natural rubber prices has been a major driver for the growth of synthetic rubber. Butyl rubber is a type of synthetic rubber mostly used in tyres and tubes, sealants, adhesives, protective clothes, pharmaceutical stoppers and closures, etc. The growing demand for butyl rubber in the automobile, construction and healthcare sectors has attracted researchers to explore various types of cationic co‐initiators. Cationic initiating systems play a vital role in controlling polymer microstructure, molecular weight, unsaturation content, etc. The present review covers numerous developments in the field of cationic copolymerization of isobutylene and isoprene. The review summarizes the chemistry of initiating systems based on boron, aluminium, aluminoxane, zinc, metallocenes and rare earth metals. It also gives brief information about the commercial process (slurry and solution) and structural characterization of butyl rubber. © 2021 Society of Chemical Industry

A theoretical study of the mechanism of cationic polymerization of isobutylene catalysed by EtAlCl2/t-BuCl with bis(2-chloroethyl)ether in hexanes

“…17,20 It should be emphasized that polymerization of IB with different initiators and catalysts has also been reported. [2][3][4]7,8,11,12,[18][19][20]29,32,33 However, very few studies investigating the cationic polymerization mechanism of IB by quantum chemistry methods have been reported.…”

“…Cationic polymerization is the main route in industry to realize polymerization of isobutylene (IB) with controllable molecular weight and monomer sequence. 1,2 Poly(isobutylene) (PIB) has a wide range of applications depending on its molecular weight. In general, PIB is classified as high-(M n 4 100 000 g mol À1 ), medium-(M n = 10 000-100 000 g mol À1 ), and low-molecularweight (M n o 5000 g mol À1 ) PIB.…”

Fast, Efficient, Catalyst-Free Epoxidation of Butyl Rubber Using Oxone/Acetone for Improved Filler Dispersion

“…Butyl rubber is prepared by the cationic copolymerization of isobutylene and isoprene (0.5–2.5 mol %). − The incorporation of isoprene units provides butyl rubber with unsaturation, which allows for vulcanization and further postpolymerization functionalization. − Despite the low unsaturation as compared to other synthetic rubbers such as butadiene rubber (BR), butyl rubber is widely used as an innerliner in tires and for pharmaceutical stoppers owing to its exceptional impermeability to gas resulting from the densely packed polymeric chains. , Meanwhile, in rubber compounding, fillers such as carbon black, clay, and silica are often added to reduce the cost and improve the physical properties of rubber compounds . The dispersion of fillers in a rubber compound plays an important role in the performance of a rubber product. , However, because of the nonpolar nature of butyl rubber, the dispersion of fillers, especially polar fillers such as silica, into the butyl rubber matrix is difficult .…”

Exploring the Potential Hormonal Effects of Tire Polymers (TPs) on Different Species Based on a Theoretical Computational Approach

“…NR is the most commonly used rubber polymer in truck tires, accounting for 75% of global NR utilization [ 12 ]. Additionally, common tire rubbers include butadiene rubber (BR), nitrile–butadiene rubber (NBR), and isobutylene–isoprene rubber (IIR) [ 13 , 14 , 15 , 16 , 17 ]. Tire-rubber particles are released and accumulate during vehicle driving and braking of vehicles; the particles then flow into water bodies after being washed by rain and enter various environmental media [ 18 , 19 ].…”