PHYSICAL-CHEMISTRY OF TOPOLOGICAL DISORDER IN POLYMERS - SOME COMMENTS ON REACTIONS KINETICS OF LOW-MOLECULAR ANTIOXIDANTS

Retardation of polymer oxidation by reaction of antioxidants with free macroradicals is considered. Being low-molecular compounds, antioxida nts dissolved in a polymer are predominantly present in certain struct ures, sorption centers, formed around knots, folds and various entangl ements of the polymer chains remaining even in the polymer melt. Becau se direct data on reaction kinetics between antioxidants and free macr oradicals are inaccessible, some regularities of the process may be co nsidered using the method of critical antioxidant concentrations. The data support the assumption that only mobile antioxidant molecules non -captured by sorption centers participate in chain termination. (C) 19 98 Elsevier Science Ltd. All rights reserved.