Patent ID: 6855788
Filing Date: 2005-02-15
Classification: C08G,H01B,H01M,Y02E

Abstract:
1. A process for the preparation of a copolymer in a stainless steel reactor; said copolymer having a chain comprising ethylene oxide, —O—CH 2 —CHR units, in which R is a substituent having a reactive function cross-linkable by free radical process, and optionally, —O—CH 2 —CHR′ units, in which R′ is a substituent having no reactive function cross-linkable by free radical process; said copolymer having a polydispersity index (I)=Mw/Mn lower than or equal to 2.2, a number average molecular weight Mn greater than or equal to 20,000 and a random distribution of monomer units; said process comprising the steps of: drying said stainless steel reactor by washing it with a solution containing an initiator and removing said initiator before the introduction of the reagents in order to remove impurities therefrom; distilling said ethylene oxide, and drying an aprotic solvent and the monomer units on molecular sieves in order to lower their water content to less than 100 ppm; and reacting said ethylene oxide and said monomer units in said stainless steel reactor in said aprotic solvent in the presence of an anionic polymerization initiator to yield said copolymer.