Polyisobutylene definition
Polyisobutylene. “Polyisobutylene Arrangements”, “Polyisobutylene Exclusivity”, and “Polyisobutylene Notification”; and
Polyisobutylene means any polymer, including highly reactive polyisobutylene and regular polyisobutylene, primarily produced by polymerization of at least 50% isobutylene and having an average molecular weight of at least 400, including but not limited to any product resulting from any use of the polymer in blends and/or converted forms.