Optimization of physical and mechanical properties of PC/ABS/PMMA blends by mixture design approach

This study aims to investigate the recycling of end-of-life computer plastics, focusing on polycarbonate (PC) and acrylonitrile–butadiene–styrene (ABS) copolymer, which constitute a significant portion of collected computers. Through differential scanning calorimetry and infrared spectroscopy analyses, the properties of raw PC, ABS and poly(methyl methacrylate) (PMMA) were evaluated. Various blends of PC and ABS were prepared, incorporating different percentages of recycled PMMA as a cost-effective coupling agent. These blends were processed through melt compounding using a contra-rotating twin-screw extruder and subsequently shaped by injection molding. An experimental mixture design was applied to evaluate the mechanical and physical properties of the composite materials, including melt flow index, hardness, flexural strain at break and Charpy impact strength. The results of the desirability analysis indicated that the optimal blend for achieving a balance between mechanical and physical properties consists of a high PC content (approximately 80% or more), a low ABS content (less than 20%) and less than 5% recycled PMMA. © 2024 Society of Chemical Industry.