Effect of poly(methyl methacrylate)-modified natural rubber on the mechanical properties of poly (methyl methacrylate)

Poly (methyl methacrylate) (PMMA) is a hard and brittle thermoplastic. Thus, its application is limited. PMMA-modified natural rubber (MNR) is a NR derivative which was synthesized in the laboratory. MNR has lower glass transition temperature, Tg as compare to PMMA. This research utilized the modified dynamic vulcanization which rubber was separately compounded with curatives by using a two-roll mill and the resultant rubber compound was added into PMMA during melt mixing. This technique effectively reduces the limitation of the mixing rate and dispersion of curatives in both the thermoplastic and elastomer components can be improvement. The blend of PMMA/MNR is expected to produce a physical blend with better mechanical properties at optimum melt mixing parameters. Based on investigation done for different parameters (processing temperature, shear rate measured via rotor speed and total missing time), the recommended melt mixing parameters are given at processing temperature of 200 °C, rotor speed of 50 rpm and total mixing time of 8 min. This technique produces blends with optimum properties, as opposed to prolonged shear technique which produce negative effect to PMMA/MNR blend.