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The structure and morphology of syndiotactic polystyrene injection molded coupons
Author(s) -
Evans A. M.,
Kellar E. J. C.,
Knowles J.,
Galiotis C.,
Carriere C. J.,
Andrews E. H.
Publication year - 1997
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.11656
Subject(s) - crystallinity , materials science , scanning electron microscope , differential scanning calorimetry , polystyrene , amorphous solid , composite material , microstructure , tacticity , polymer , morphology (biology) , optical microscope , raman spectroscopy , crystallography , optics , genetics , biology , polymerization , chemistry , physics , thermodynamics
The structure and morphology of syndiotactic polystyrene (sPS) injection molded coupons have been investigated using wide angle X‐ray scattering (WAXS), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), light microscopy, and laser Raman spectroscopy (LRS). By sectioning the samples at approximately 200 μm increments, profiles across “hot molded” (oil heated to 140°C) and “cold molded” (water heated to 104°C) coupons, could be built up. Using DSC and WAXS, variations in crystallinity and polymorphic phases were observed. The crystallinity was found to remain fairly constant in the “hot molded” samples, whereas the cold molded samples had a pronounced “amorphous” skin, before becoming more uniform towards the center of the specimen. Characterization of the polymers' microstructure, in the molded plaques, was achieved by optical birefringence. The surface of the plaques were successfully etched with an acid/permanganate solution, prior to SEM studies, to reveal their morphology. Overall, the coupons showed very little orientation effects and the structure appeared to be consistent with that of a semicrystalline polymer, crystallized under relaxed conditions.