CRYSTALLIZATION BEHAVIOUR AND INFRARED SPECTRUM OF POLYETHER-ESTER HOMOLOGS FROM HALOGENATED p-HYDROXYBENZOIC ACID

Abstract

Glass transition and crystallization were studied for polyether-ester homologs having halogen substituent on the benzene ring; Polyethylene 1, 2-diphenoxyethane-p, p′-dicarboxylate (PEB), Polyethylene 1, 2-di (o-chlorophenoxy) ethane-p, p′-dicarboxylate (PEB_Cl2), Polyethylene 1, 2-di (o-bromophenoxy) ethane-p, p′-dicarboxylate (PEB_Br2), Polyethylene 1, 2-di (o, o′-dichlorophenoxy) ethane-p, p′-dicarboxylate (PEB_Cl4) and Polyethylene 1, 2-di (o, o′-dibromophenoxy) ethane-p, p′-dicarboxylate (PEB_Br4).
Glass transition temperature measured by DTA increased in the order, PEB<PEB_Cl2_??_PEB_Cl4<PEB_Br2<PEB_Br4. Cold crystallization temperature measured by DTA increased in the order, PEB<PEB_Cl2<PEB_Br2, and PEB_Cl4 and PEB_Br4 showed no crystallization peak. The crystallization rate followed by the change of density decreased in the order, PEB>PEB_Cl2>PEB_Br2>PEB_Cl4. Crystallinity estimated by the X-ray diffraction intensity curve also decreased by halogen substitution. Effect of halogen substitution and crystallization on the infrared spectrum of polyether-ester homologs was studied. Some discussion was made on these results.