Nonhalogen flame retarded poly(butylene terephthalate) composite using aluminum phosphinate and phosphorus‐containing deoxybenzoin polymer

Abstract

ABSTRACTSynergistic charring effect was observed between aluminum diethlyphosphinate (AlPi) and 4,4‐bishydroxydeoxybenzoin‐polyphosphonate (BHDB‐PPN) in the poly(butylene terephthalate) composite. By combining them together, robust UL 94 V0 rating was achieved at 0.8 mm thickness for poly(butylene terephthalate)/AlPi/BHDB‐PPN composite which exhibited better mechanical properties than the samples without BHDB‐PPN. The thermal degradation behavior of BHDB‐PPN was investigated by analyzing its evolution and residues under different temperatures. It was found that the radical termination reaction of formed benzyl group may play a critical role in the high charring capacity of BHDB‐PPN. Part of the volatile diethlyphosphinate fragments reacted with the degradation intermediates from BHDB‐PPN to form big chain structure for further carbonization was a possible reason for the synergistic charring effect between AlPi and BHDB‐PPN. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45537.