Upcycling poly(vinyl chloride) waste tubes: Studies of thermal stability and kinetics of films made of waste polyvinylchloride tube at the initial steps of degradation

Polyvinylchloride (PVC) tubing products almost have replaced cast iron sewer and piping systems for water and wastewater collections; it also replaced metal and wood in window frames in construction. PVC has a high value, and its resin production continues to grow yearly at a considerable rate. Availability of the disposed or postconsumer PVC (wPVC) mimics a pseudo-renewable resource of wPVC, which creates many upcycling, recycling, and downcycling that result in many economic opportunities, besides reducing its burden on the environment while saving energy. This work presents the thermal characteristics of a film made of wPVC (wPVCf). Six samples of wPVCf were analyzed by its own heating, rate appropriate for kinetics properties evaluation, using a thermogravimetric analysis (TGA) instrument. The isoconversional degradation energy barrier (E-a,E-alpha) values were evaluated by applying 14 kinetic models, f(alpha), to the TGA data assuming that the degradation process follows a pseudo-single component model. The values of E-alpha,E-alpha obtained from all models for each given alpha value were close to each other with a standard deviation of less than 0.1 kJ mol(-1) indicating the validity of the method. The results were consistent with the kinetics data reported in the literature for pure PVC.

Automated summary

PVC tubing products have replaced cast iron sewer and piping systems, metal and wood in window frames. The availability of disposed or postconsumer PVC allows for upcycling, recycling, and downcycling, creating economic opportunities and reducing environmental burden. This study examines the thermal characteristics of a film made of wPVC and evaluates the isoconversional degradation energy barrier values using kinetic models.