Poly-2-isopropenylnaphthalene poly-butadiene-1,3-block copolymers and method for their production

Abstract

Poly-2-isopropenylnaphthalene-poly-butadiene-1,3-block copolymers and method for their production. Di- or tri-block polymers with molecular weights of at least 10,000 are formed from, respectively, a poly-2-isopropenylnaphthalene block and a poly-butadiene-1,3 block, and a poly-2-isopropenylnaphthalene block and a poly-butadiene-1,3 block as well as a further poly-2-isopropenylnaphthalene block. The products display rubber-elastic characteristics of the known block polymerizates, with improved high-temperature stability. The polymers are formed by reacting 2-isopropenylnaphthalene in an inert, aliphatic or cycloaliphatic hydrocarbon solvent, at low temperature, with alkalimetal, alkalimetalalkylene, -arylene or -hydride catalyst, into a poly-2-isopropenylnaphthalene block. This formed polymeric anion then has poly-butadiene-1,3-block added to it at its active chain end. If necessary, a second poly-2-isopropenylnaphthalene block is added. The reaction becomes terminated in known manner through the addition of water, alcohol or acid. Lithium-alkyl is the preferred catalyst; tetrahydrofuran is the preferred solvent; the reaction is performed at temperatures between 0.degree. and -80.degree. C., preferably between about -50.degree. C. and -80.degree. C. It is also preferred to initially provide the 2-isopropenylnaphthalene in the solvent at about 0.degree. to 5.degree. C.

Dependencies are inferred from the claim text.