Biaxial orientation.pdf (349.15 kB)
Biaxial orientation of poly(vinyl chloride) compounds Part 2 –Structure–property relationships and their time dependency
journal contribution
posted on 2009-04-17, 16:13 authored by David Hitt, Marianne GilbertX-ray diffraction and thermomechanical analysis have been used, respectively, to examine structural order and shrinkage behaviour for oriented samples of rigid and flexible poly(vinyl chloride) (PVC). Results were compared with previously measured tensile properties and structure–property relationships explored. X-ray diffraction showed that drawing produces planar crystallite orientation in PVC sheets. If drawing and subsequent annealing conditions are held constant, but draw ratio is varied, there is good correlation between structural order measured by X-ray diffraction and tensile strength. Increased annealing time and temperature improve crystallite order and dimensional stability, while tensile strength is unchanged. The greatest enhancement in tensile strength is achieved by stretching PVC towards its maximum draw ratio at 90°C, but optimum thermal stability of the oriented structure is achieved when higher annealing temperatures are used. Room temperature recovery is observed for flexible PVC when the material has a glass transition temperature below ambient. This can be delayed by increased annealing time and temperature, and by increased draw ratio.
History
School
- Aeronautical, Automotive, Chemical and Materials Engineering
Department
- Materials
Citation
HITT, D.J. and GILBERT, M., 2000. Biaxial orientation of poly(vinyl chloride) compounds Part 2 –Structure–property relationships and their time dependency. Plastics, Rubber and Composites, 29 (3), pp. 149 - 160Publisher
© Maney PublishingVersion
- VoR (Version of Record)
Publication date
2000Notes
This article was published in the journal, Plastics, Rubber and Composites [© Maney Publishing] and is available at: http://www.ingentaconnect.com/content/maney/prcISSN
1465-8011;1743-2898Language
- en