Synthesis of cyclic diepoxide — HALS addition polymers and their photostabilizing effects on styrenic polymers

Abstract

A new cyclic, hindered amine light stabilizer (HALS) was prepared by the addition polymerization of a diepoxide and 4-amino-2,2,6,6-tetramethylpiperidine, and its photostabilizing effects on styrenic polymers were examined. The chemical structure of cyclic HALS was characterized by MALDI-TOF mass spectrometry. The prepared cyclic HALS had a moderate molecular weight (M w = 900~1,100) and high thermal stability (T d ≈ 300 o C) that were compatible with styrenic polymers, such as polystyrene and styrene-butadiene rubber. The photostabilization effect of cyclic HALS was similar to or better than that of Tinuvin 770, a commercially available polymeric HALS. A synergistic effect between cyclic HALS and a UV absorber on the inhibition of photooxidation was observed.