Daniel Schmidt, Plastics Engineering
All materials have the potential to cause both positive and negative impacts on human health and the environment, and poly vinyl chloride (PVC) is certainly no exception. Filling the needs of end users while minimizing the hazards associated with PVC based materials is becoming increasingly challenging for the plastics industry. The use of lead stabilizers and phthalate plasticizers in PVC wire and cable formulations in particular is a significant problem in this regard. With that in mind, this study investigates the production of lead- and phthalate-free PVC nanocomposites as high performance, non-toxic alternatives to current materials. The investigators have chosen environmentally benign clay nanofillers and vegetable oil-based plasticizers in order to achieve this goal, with synergistic interactions expected between the two additives thanks to the excellent dispersability of nanoclays in epoxidized vegetable oil and the stabilizing effects reported for both additives.
Based on a realistic wire and cable formulation, PVC has been dry-blended with various stabilizers (lead or non-lead) and plasticizers (phthalate or epoxidized vegetable oil), compounded using a twin-screw extruder with or without a low loading of nanoclay (chosen based on our past work with FPVC nanocomposites), pelletized, and sheet extruded for properties analyses. The study reports the results to date, with a focus on matching the mechanical.