Comparative Study on the Effect of Different Rubber Waste as Filler on Recycled Polyvinylchloride Composites

Improper disposal and management of plastic and rubber waste pose significant environmental and health risks, while also contributing to resource depletion. With the increasing demand for polymeric materials, it is crucial to develop more sustainable solutions for recycling and reutilizing waste into sustainable and eco-friendly products. This study explores the development of composite material made from recycled polyvinylchloride (rPVC) sourced from carpet backing material and waste rubber particles from two different sources namely LeHigh (cryogenically ground truck tire rubber) and ALUM (scrap rubber from scuba diving products). The composites were melt mixed using a Brabender internal mixer at 165°C, with filler content ranging from 0–30 wt%. The study evaluates the impact of LeHigh and ALUM as fillers in rPVC composites, aiming to meet performance standards for car floor mats. Processability data showed that the saturation point for both fillers in rPVC was at 20 wt%, beyond which the composites became immiscible and sticky. Properties evaluation revealed that LeHigh offered better tensile strength, compatibility and overall performance as compared to ALUM. The optimal formulation, with 20 wt% LeHigh and 10 wt% ALUM, met the performance requirements for car floor mat application, including a minimum tensile strength of 5 MPa, a minimum elongation at break of 25%, water absorption of less than 2.5%, and shore A hardness of 90 ± 5. Beyond 20 wt% filler, agglomeration and increased processing torque led to poor processability and reduced performance. This work highlights the importance of selecting the right materials and compounding formulations for recycling plastic and rubber waste into valuable, sustainable composites, contributing to industrial innovation, environmental sustainability, and the circular economy.