Properties of a thermoplastic elastomer derived from polyacrylate/PVC

The polymerization of vinyl chloride in the presence of suitable elastomer dispersions yields so-called PVC graft polymers. These may be processed on standard PVC equipment into flexible articles having a high mechanical strength and good indentation recovery. The ultimate physical properties are governed largely by the separation during processing into PVC-rich and elastomer-rich phases. For a poly mer of poly(butyl acrylate) and PVC, this separation is examined by means of dynamic mechanical analysis (DMA). A method is presented by which it is possible to quantitatively classify the PVC molecules on the basis of grafted and ungrafted fractions as well as their respective size of the domains. The method allows the influence of processing conditions on stiffness, hardness, tensile strength, and elongation at break to be explained. Furthermore, reversible and irreversible property changes are shown to occur during reprocessing of test specimens.