Observation and evaluation of scratch characteristics of injection-molded poly(methyl methacrylate) toughened by acrylic rubbers

Poly(methyl methacrylate) (PMMA) is frequently toughened by blending with elastomers such as acrylic rubbers to improve its toughness, but the addition of acrylic rubbers to PMMA deteriorates its scratch properties. In this study, the scratch properties of PMMA toughened by the addition of acrylic rubbers were investigated by performing static and progressive scratch tests. Three scratch damage modes, namely, mar/plowing, whitening, and cutting modes, were identified by observing the scratch damage using various microscopy techniques. In addition, two critical loads for defining the variation of scratch damage mechanisms were recorded to evaluate the scratch resistance of rubber-toughened PMMA samples.