MECHANICAL-PROPERTIES OF PLASTICIZED POLY(VINYLCHLORIDE) - EFFECT OF DRAWING AND FILLER ORIENTATION

Reinforcement of plasticized poly(vinylchloride) was achieved by the u se of two anisotropic fillers: talc and a lead carboxylate. The orient ation of such fillers was developed during the extrusion processing. T hen, in the present paper, we studied the correlations between extrusi on conditions (draw ratio, temperature), development of particle orien tation (talc, lead stabilizer) and tensile properties of a plasticized polyvinylchloride. X-ray diffraction measurements have allowed us to analyse orientation of the particles which also became evident through tensile property results. This work shows that talc is a good candida te for filling PVC formulations. Furthermore, good orientation is achi eved with the extrusion conditions used. Moreover, the orientation of the lead stabilizer which has a lamellar shape leads to an increase in Young's modulus. The enhancement of the Young's modulus obtained by t hese two fillers is well modelled by the Halpin and Tsai law, consider ing that the platelets are oriented in the stretching direction. Conce rning drawing, the stretching temperature has proved to be of particul ar importance, especially when it is above or below the temperature of the 'gel-liquid' transition of PVC, found to be around 205 degrees C. (C) 1998 Elsevier Science Ltd. All rights reserved.