Reutilization of waste cling film as a toughening agent and self-plasticizer in recycled poly(vinyl chloride) pipe for semi-rigid building material applications

Abstract

Alternative approaches are urgently needed for both reuse and recycling of poly(vinyl chloride) (PVC) waste. Herein, this study aims to recycle rigid PVC pipe by toughening and plasticizing it with waste cling film (CF). The CF has been first reused as a polymer additive by blending it with PVC from 0 to 50 wt% using a two-roll mill and compression molding machines. Both static and dynamic mechanical properties, morphology, thermal transition, thermal stability, and migration of the recycled PVC (rPVC) were investigated and compared to unmodified rigid PVC. Principal results showed that the CF significantly improved softness and toughness of rPVC. Remarkably increased elongation to 206 % (an 8-fold increase from the rPVC) with strain-hardening event was obtained by utilizing 50 %wt of CF, while tensile and flexural strength decreased owing to the softening effect of CF. There was the strong correlation between microstructure and static mechanical properties. The wire drawing morphology of the toughest rPVC indicated the toughening mechanism of CF via the shear banding behavior, which was inside proposed. A glass transition temperature reduction of 35 ^°C was achieved. Despite the continued migration of plasticizer in the CF modified rPVC, volatilization was diminished across all recycled formulations, leading to comparable thermal stability of the rPVCs with unmodified PVC under typical processing temperatures. According to these findings, the potential capabilities of the CF as the toughening agent and self-plasticizer of PVC for further reutilization were confirmed. This study provides a new idea for reduction of PVC waste and evaluation of their potential applications. An alternative additive, derived from flexible PVC waste, was also explored, and introduced to the polymeric system.