Method for copolymerizing monomers of different types and polymer blends contain the copolymer

Abstract

The present invention describes a process of producing block copolymers from monomers of different types by polymerization in two successive steps. The first step consists in polymerizing monomers of a first type by means of coordinated anionic catalysts comprising organo-metallic compounds of a metal of the Group IA, IIA, IIIA, or mixtures thereof of Mendeleev's Periodic Table of Elements, associated with a transition metal compound of Group IV to VIII and the second step comprises polymerizing a second type of monomer in the presence of the polymer formed in the first step and in the presence of free radical catalysts, wherein 0.01 to 100 moles of an adjuvant per mole of transition metal compound is added to the reaction medium of the first step and this adjuvant consists of a compound MY.sub.n in which M is selected from the group consisting of boron and Group IIB metals of Mendeleev's Periodic Classification of the Elements, n is the valency of M, and Y represents a member selected from the group consisting of a monovalent hydrocarbyl group, hydrogen and a halogen atom. The block copolymers thus formed can be used in preparing blends with other polymers.

Dependencies are inferred from the claim text.