Impact modification of styrene-methyl methacrylate copolymer cast sheet by using natural rubber

Abstract

Natural rubber (NR) is an economical plant of Thailand, which has an excellent property, especially flexible property. This research presents the study and preparation of high impact transparent styrene-methyl methacrylate copolymer cast sheet by using NR as an impact modifier. The copolymer cast sheets were prepared by bulk polymerization via casting process. The influence factors, such as monomer ratio and NR concentration were studied. The physical and mechanical properties of the modified copolymer cast sheet were investigated. It was found that the appropriate conditions were 90 and 80 % by weight of methyl methacrylate, 10 and 20 % by weight of styrene, 0.1 % by weight of peroxide initiator, and 0.03 % by weight of azo compound initiator. The highest impact strength of copolymer cast sheet was shown at the 20 % by weight of the natural rubber. The results show the possibility using of NR as an impact modifier for styrene-methyl methacrylate copolymer cast sheet. The using of NR, which is a natural polymer and economical plant of Thailand, instead of synthetic polymers could be useful for further development in both of economical and environmental dimensions.