Estudo da polimerização catiônica do isobuteno em solução

Abstract

Functionalized poly(isobutene) (PIB) is used as an additive in lubricating oils and gasoline. PIB can be produced through two basic routes, resulting in conventional PIB (C-PIB) or highly reactive PIB (HR-PIB). The chemical chain of C-PIB and derivatives is more dangerous and environmentally aggressive, as it involves the use of halogenates. Besides, it is costlier, as it requires additional functionalization steps. For this reason, the solution cationic polymerization of isobutene was studied to evaluate the main aspects that affect the characteristics of the final product, such as the molar mass distributions and the vinyl contents, aiming at the production of HR-PIB. Effects associated with the feeding mode, reactor volume, polymerization time, reaction temperature, water content, type and amount of cocatalyst, type of solvent and purity of the monomer load were evaluated. It is concluded that the solvent polarity, the basicity of the cocatalyst and the water content of the reaction medium are the factors that affect mostly the vinyl contents of the final product and the operation conditions required for production of HR-PIB.