Rheology, morphology, and mechanical and thermal properties of recycled PVC pipes

This article demonstrated the possibility of recycling PVC pipes by investi gating the effect of adding PVC pipes (varying from 0 to 80% wt) into two c ommercial PVC virgin grades on the rheological, morphological, mechanical, and thermal properties of the PVC blends. The results obtained showed an in crease in the melt viscosity and no change in the die swell ratio as the co ncentration of the recycled PVC was increased. The die swell ratio was obse rved to increase with temperature, this being associated with the presence of gelation that occurred at high temperature. The optimum tensile and impa ct strengths were detected, the impact strength being explained by use of S EM micrographs of the fracture surface. The hardness result corresponded we ll to the density of the compounds. The glass transition, degradation, and heat-deflection temperatures were also found to shift with the recycled PVC loading. (C) 2001 John Wiley & Sons, Inc.