PIPERAZINE-MODIFIED AMMONIUM POLYPHOSPHATE AS A HIGHLY-EFFICIENCY FLAME RETARDANT FOR POLYETHYLENE

摘要

A series of piperazine-modified ammonium polyphosphate (PA-APP) flame retardants with different structures were synthesized through ion exchange reaction.Combustion tests demonstrated that the flame-retardant LDPE system prepared could pass the UL-94 V-0 rating,and had a limiting oxygen index (LOI) of 31.5％ at 28 wt％ PA-APP containing 7 wt％ of carbon (PA-APP7).The flame-retardant efficiency of PA-APP7 is significantly higher than the other PA-APPs with more or less than 7 wt％ carbon.Experimental results proved that PA-APP7could reach the balance of an acid source,a blowing agent,and a charring agent as a mono-component intumescent flame retardant for LDPE.