SYNTHESIS AND PROPERTIES OF NOVEL FLAME RETARDANT COPOLYESTERS CONTAINING BENZOXAZOLE

摘要

In order to avoid the serious melt-dripping problems, a benzoxazole-containing bi-functional monomer named 2-(3,5-hydroxyethoxy)phenylbenzoxazole(PBm) was synthesized and introduced into the PET main-chainviacondensation polymerization.With the incorporation ofbenzoxazoleunits, the char residue obtained from combustion of the flame-retardant copolyesters containing PBm (PET-PBm x％) increased dramatically.These copolyesters still kept crystallization ability although their crystallinity and melting temperature were lower than those of PET.The LOI values increased from 22.0 of PET to 27.0 of PET-PBml0, and further increased to 29.0 of PET-PBm20.