Materials
Natural rubber, used in this experiment is filed latex from Chachoengsao Rubber Research Centre. Its dry rubber content is approximately 28 to 30 percent. The surfactant used was teric 16 A 16, nonionic class. The 50 % hydrogen peroxide (Peroxythai Ltd, Thailand) and 98 % formic acid (fisher scientific) are used to epoxidize natural rubber. N-Cyclohexyl-2-benzothiazyl sulphenamide (CBS) and Dibenzothiazyl disulphide (MBTS) was used as the accelerator. Other compounding ingredients such as zinc oxide, stearic acid, and sulphur are of commercial grades. The conventional vulcanization system (CV) was used. All other reagent, solvents and indicators used were of reagent grade and were used as supplied.