FLAME RETARDANCY AND REARRANGEMENT REACTION OF POLYPHENYLENE-ETHER POLYSTYRENE ALLOY/

The flame retardancy and the rearrangement reaction of polyphenylene-e ther [poly-(oxy-2,6-dimethyl-1,4-phenylene), PPE] and polyphenylene-et her/polystyrene (PS) alloys have been studied. The flame retardancy of PPE blended with phosphates was proportional to PPE content as well a s to the phosphates. The surface temperatures of PPE during a combusti on was higher than that of PS, whereas PPE is more flammable than PS. The element analysis of the polymer surface showed that carbon was ric her compared with the content of the newly synthesized PPE. Four monom eric and eight dimeric scission products were recovered by thermogravi metric-mass (TGA-MASS) analysis at high temperature in inert atmospher e. These structures of the scission products suggested that the rearra ngement reaction occurred in combustion at high temperature. Namely, t he formation of carbonaceous materials on the surface followed the rea rrangement reaction and dehydration which was accelerated by the addit ion of aromatic phosphates. (C) 1997 John Wiley & Sons, Inc.