Polymerization of isoprene in the presence of amines containing lithium

Abstract

A study was made of the possible use of tertiary N-substituted allylamines containing lithium as di- and trifunctional initiators of anionic polymerization of isoprene. The compounds are soluble in hydrocarbons and are of the type: R n N(CH 2CH=CH 2) 3− n (R=CH 3; CH 2C 6H 5;  CH 2CH=CH 2). To evaluate the functionality of initiators, hydroxyl end groups were added to the oligoisoprene obtained via the stage of epoxidation, followed by theatment of the product with acid. The average functionality of oligoisoprene diols, which was close to two, was only obtained when using initiators prepared from diallylbenzylamine and triallylamine. Unfilled rubber was synthesized by changing oligoisoprene diol to oligoisoprenedi-isocyanate and subsequent crosslinking with triaminotriphenyl methane. A sol content in the rubber obtained much higher than that in conventional vulcanizates and a high equilibrium swelling index indicate that the initial oligoisoprene diol contains not only bi-, but also mono-functional macromolecules.