Combined oligomeric light and heat stabilizers

A series of terpolymers containing structural units of hindered amine stabi lizer (HAS), antioxidant of diphenylamine type and octadecyl alkyl chain ha s been prepared by radical oligomerization initiated by AIBN. Monomers bear ing HAS represented acrylate, methacrylate or acrylamide of 2,2,6,6-tetrame thyl and 1,2,2,6,6-penta-metbylpiperidine respectively. Second monomer in t erpolymers was 4-amino-diphenylamine acrylamide or methacrylamide and the t hird one n-octadecyl acrylate. Molecular weights of oligomers lay in the re gion 4000-6500. The molar ratio of monomers in oligomers was approximately the same as in the mixtures of monomers before oligomerization (1:1:1). Oli gomeric stabilizers were tested as photostabilizers in polyoctenamer and po lypropylene (PP) and as thermostabilizers in PP at 130 degreesC. Stabilizin g efficiency for all oligomeric stabilizers was roughly the same in photoox idation of PP. In the case of thermooxidation, the oligomer TMPA/DPA/ODA sh owed several times better efficiency than other oligomers. (C) 2000 Elsevie r Science Ltd. All rights reserved.