Krystalická struktura a morfologie čerstvě připravených vzorků symetrických aromatických polyesterů I.poly(p-fenylen tereftalát)

Abstract

Morfologie a krystalová struktura poly(p-fenylu tereftalátu) ( PPT) připravovaného polymerací v tenké vrstvě ( CTFMP) a v roztoku ( CTFSP) a roztokovou polymerací ve větším objemu, byla charkterizovaná transnisní elektronovou mikroskopií, elektronovou difrací a molekulovým modelováním.

The morphology and crystal structure of poly(p-phenylene terephthalate) (PPT), prepared by confined thin film melt (CTFMP) and solution (CTFSP) and bulk solution polymerization, were characterized by transmission electron microscopy, electron diffraction and molecular modeling. The unit cell is monoclinic (P2(1)/a space group) with parameters a = 7.89, b = 5.49, c =12.65 Angstrom, alpha = gamma = 90degrees, 6= 100.33degrees, density = 1.48 g/cm(3), the a, b and beta values differing slightly from those reported previously in the literature. A degree of variation in relative intensities of hk0 reflections in, apparently, untilted [001] ED patterns was observed from a given sample, suggesting some variation in molecular packing. ED evidence was found for a second phase, with [001] appearing the same as for phase 11 of the related poly(p-oxybenzoate) (PpOBA) polymer. CTFMP crystals polymerized above 220degreesC (up to 370degreesC) and CTFSP crystals polymerized at 300degreesC consisted of lamellae 100-200 Angstrom thick.