Shape memory effect of dehydrochlorinated crosslinked poly(vinyl chloride)

✍ Scribed by Viera Skákalová; Vladimír Lukeš; Martin Breza

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 1008 KB
• Volume: 198
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1997.021981014

✦ Synopsis

Abstract

Crosslinked poly(vinyl chloride) (CPVC) samples with various extent of dehydrochlorination x, exhibiting a shape memory effect, were prepared. In order to determine the optimal structure for the shape memory effect, electron microscopy, dilatometry, differential thermal analysis (DTA), thermal conductivity and tensile strength measurements were performed. The extremum of all the measured physical properties was found for the sample with x = 12%, corresponding to the optimal structure. The characteristic parameters of the expansion process were calculated from the fits of the experimental data. The extremum was qualitatively predicted by simplified quantum chemical models of a double PVC chain using the semiempirical AMI method. The generalized zip mechanism of CPVC dehydrochlorination might explain the extremum due to mutual chain reorientation with increasing x.