The influence of heat treatment on scratch behavior of polymethylmethacrylate (PMMA)

• The effect of heat treatment durations on scratch behavior of PMMA was determined.
• The effect of heat treatment durations on microhardness of PMMA was determined.
• Microhardness values of PMMA increase with increasing heat treatment duration.
• Heat treatment of 3 h results in best scratch resistance due to higher surface hardness.

This work aims to determine the effect of heat treatment at 85 °C at three different durations (1 h, 2 h and 3 h) on scratch behavior and microhardness of polymethylmethacrylate (PMMA). Microhardness test results showed that microhardness values increase with increasing the heat treatment durations according to the neat PMMA samples. Scratch test results showed that heat treatment at 3 h results in the best scratch-resistance due to higher surface hardness as compared to other samples. Moreover, scratch deformation mechanisms of PMMA samples were determined by using a scanning electron microscope (SEM). Two important damage mechanisms were determined as “ironing” and “cracking” for heat treated PMMA samples.