Effect of temperature on scratch and mar behaviors and visibility of amorphous thermoplastics

Scratch and mar behaviors are increasingly considered a measure of polymeric materials durability and suitability for a variety of high-end functional and engineering applications, especially the automotive and consumer electronics sectors. Plastic materials may be exposed to elevated temperatures during service. For instance, plastic components used for car interiors and exteriors may be subjected to elevated temperatures during summer months, which may directly impact scratch and mar resistance. The present study aims to determine and quantify scratch and mar resistance and visibility at high temperatures (from 23 °C up to 90 °C) for several thermoplastic polymers, namely polycarbonate, polycarbonate copolymer, poly(methyl methacrylate), and styrene-acrylonitrile. Yield strain is identified as a quantitative predictor for scratch and mar visibility resistance across multiple thermoplastics and temperature ranges. These findings provide guidelines for polymer design for high-temperature applications in automotive interiors. Implications of the present study for designing scratch and mar resistance of polymers are discussed. • Scratch and mar behaviors of thermoplastics from room temperature to 90 °C • Scratch and mar resistance decrease with increasing temperature • Scratch behavior shows a strong correlation with compressive yield stress • Yield strain predicts material resistance to scratches and mar visibility