Polymer Engineering and Science, Vol.37, No.11, 1858-1864, 1997
Biaxial Orientation of Poly(Vinyl Chloride) Compounds - Interaction Between Drawing, Structure, and Properties
Rigid poly(vinyl chloride) (PVC) sheets were stretched uniaxially (at constant width), equally biaxially, and unequally biaxially to various draw ratios. Tensile properties, density, and birefringence of the stretched sheets were measured, and their wide angle X-ray diffraction traces recorded. Comparison of results showed the highest crystallite and overall orientation and density in the uniaxial samples, and lowest values for the equal biaxial samples. Drawing resulted in the alignment of some existing crystallites In the plane of the film, together with the formation of new mesomorphous structures. Changes in tensile strength were attributed to overall orientation.
Keywords:MOLECULAR-ORIENTATION;POLYMERS