Identification of unknown substances in food contact polystyrene

Abstract

Various substances present in polystyrene products were identified by GC/MS and NMR. The chemical structures of 13 unknown substances were confirmed or deduced to be 1,3-diphenylpropane, cis- and trans-1,2- diphenylcyclobutane, 2,4-diphenyl-1-butene, 2,4,6-triphenyl-1-hexene, 1- phenyl-4-(1'-phenylethyl)tetralin and isomers, triphenylcyclohexane, 2,4,6,8- tetraphenyl-1-octene and an isomer, and 2,4,6,8,10-pentaphenyl-1-decene. They are styrone oligomers, which were presumably formed by side reactions during the polymerization of styrone and remained in the final products.