Radial polymers prepared by stabilized free radical polymerization

US6369162B1 · kind B1 · utility

Assignee

• The Lubrizol Corporation · US

Inventors

• Daniel C. Visger · Mentor, US
• Richard M. Lange · Euclid, US

Key dates

• Filing date: Jun 21, 2000
• Grant date: Apr 9, 2002
• Expiry date: Jun 21, 2020

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C10M2217/06
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

A process for preparing a radial polymer comprising at least 3 polymeric arms and a central core comprising a polymerized di- or polyfunctional monomer, said process comprising the steps,(a) polymerizing at an elevated temperature, a charge comprising at least one free radical-polymerizable monomer to prepare a stabilized active polymer block (A) using a free radical polymerization process,wherein a stable free radical agent is employed during the polymerization, thereby preserving the stabilized active polymerization site at the terminus of the polymer; optionally(b) adding at least one additional free radical-polymerizable monomer, at least one of which is different from the monomers making up the first charge of monomers, to the stabilized active polymer block (A); and further reacting the mixture using a free radical process to effect copolymerization of said monomers, thereby preparing an A-B block copolymer having a stabilized active polymerization site at the terminus of the polymer; then(c) adding at least one coupling agent comprising a polyfunctional monomer and reacting the stabilized active polymers from (a) or (b) with a coupling agent to form a radial polymer.The pres…