X-RAY STUDY OF STRUCTURAL REARRANGEMENTS IN SOLVENT-CRAZED SEMICRYSTALLINE POLY(ETHYLENE-TEREPHTHALATE) DURING TENSILE DRAWING IN A LIQUID ENVIRONMENT AND DRYING

Structural rearrangements in solvent-crazed semicrystalline PET that t ake place during tensile drawing of polymer in the presence of surface -active liquid environments and further drying under various condition s were characterized by X-ray analysis. Application of both SAXS and W AXS allowed one to put forth a new approach for estimation of the para meters of microporous structure of the crazed samples. During tensile drawing of semicrystalline PET to high tensile strains (330%), crazes with highly disperse structure and high specific surface area were sho wn to be preserved. As compared with amorphous PET, in the case of sem icrystalline PET, irregular arrangement of craze fibrils in the crazes was observed. This disorder was likely to be accounted for by the eff ect of supermolecular structure of semicrystalline polymer on the deve lopment of craze fibrils during solvent crazing.