MESOMORPHIC BEHAVIOR AND MULTIPLE MELTING TRANSITION OF AROMATIC POLYESTER FRACTIONS

【摘要】 <正> Fractions of an aromatic polyester have been studied by DSC, polarizing microscopy, SALS and WAXS techniques. The intrinsic viscosity of the samples in tetrachloroethane is ranging from 0.197 to 0.591dl / g. All the samples exhibit enantiotropic liquid crystal behavior, and the thermal stability of mesophase decrease withlowering the molecular weight of the fractions. The glass transition temperature keeps almost constant for allthe samples, however its value for supercooled mesophase is about 20~C lower than that for amorphous phase.Multiple melting phenomenon was also found for samples crystallized from their mesophases and was similarto that observed for nonliquid crystal forming polymers.更多还原

【Abstract】 Fractions of an aromatic polyester have been studied by DSC, polarizing microscopy, SALS and WAXS techniques. The intrinsic viscosity of the samples in tetrachloroethane is ranging from 0.197 to 0.591dl / g. All the samples exhibit enantiotropic liquid crystal behavior, and the thermal stability of mesophase decrease withlowering the molecular weight of the fractions. The glass transition temperature keeps almost constant for allthe samples, however its value for supercooled mesophase is about 20~C lower than that for amorphous phase.Multiple melting phenomenon was also found for samples crystallized from their mesophases and was similarto that observed for nonliquid crystal forming polymers.更多还原