Synchrotron studies of polymers at DND-CAT

• Published in: Journal of applied crystallography Vol. 33; no. 3-1; pp. 704 - 708
• Main Authors: Londono, J.D., Davidson, R.V., Brill, D., Roach, D.H., Leach, R.A., Quintana, J.P.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England Munksgaard International Publishers 01.06.2000; Blackwell
• Subjects: Applied sciences; Exact sciences and technology; Mechanical properties; Organic polymers; Physicochemistry of polymers; Properties and characterization; Ethylene terephthalate polymer; Deformation; Stress strain relation; Segmented polymer; Ether copolymer; Thermoplastic rubber; Small angle X ray scattering; Experimental study; Mechanism; Ester copolymer; Butene oxide copolymer; Synchrotron radiation; Elongation (mechanics)
• ISSN: 1600-5767; 0021-8898; 1600-5767
• DOI: 10.1107/S0021889899013291

Two examples are presented that illustrate the capabilities of DND‐CAT instrumentation for the study of the effects of processing on polymers. Firstly, a thermoplastic elastomer, Hytrel®, was stretched while 2‐D data were collected simultaneously. The Hytrel® data show that the yield point of the stress‐strain curve is associated with the sudden appearance of a four‐point pattern. At higher deformations, strain‐induced crystallization and the destruction of the hard segment domains lead to a substantial decrease of the contrast as monitored by the SAXS invariant. Prior to breakage, the extent and intensity of an equatorial streak develops as the material fibrillates. Secondly, SAXS and WAXS data were collected from quenched and annealed Poly(ethylene terephthalate) (PET) samples mounted on a DSC cell, to characterize the pre‐melting shoulder in this material. Results show that substantial melting and re‐crystallization occurs within the range of this shoulder in the quenched sample.