Crystalline morphology in a series of CH3-substituted main chain thermotropic aromatic polyesters with even and odd numbered methylene spacers has been studied by polarizing optical microscopy (POM), scanning electron...Crystalline morphology in a series of CH3-substituted main chain thermotropic aromatic polyesters with even and odd numbered methylene spacers has been studied by polarizing optical microscopy (POM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). On crystallization from solution evaporation spherulites of radial structure were observed in the polymers with even numbered spacers, but spherulites with concentric rings form in the polymer with odd numbered spacers. Both spherulites have a lamellar structure, which is about 10 nm in thickness. On crystallization from nematic glassy state spherulites can not be grown; lamellar structure was only observed around disclinations in a specimen during crystallization. Ln the case of crystallization from nematic melt two types of spherulites can be observed far the sample with even numbered spacers. For the sample with add numbered spacers spherulites can not be formed, but only irregular crystallites.展开更多
文摘Crystalline morphology in a series of CH3-substituted main chain thermotropic aromatic polyesters with even and odd numbered methylene spacers has been studied by polarizing optical microscopy (POM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). On crystallization from solution evaporation spherulites of radial structure were observed in the polymers with even numbered spacers, but spherulites with concentric rings form in the polymer with odd numbered spacers. Both spherulites have a lamellar structure, which is about 10 nm in thickness. On crystallization from nematic glassy state spherulites can not be grown; lamellar structure was only observed around disclinations in a specimen during crystallization. Ln the case of crystallization from nematic melt two types of spherulites can be observed far the sample with even numbered spacers. For the sample with add numbered spacers spherulites can not be formed, but only irregular crystallites.
