SULPHUR-FREE PREVULCANIZATION OF MALAYSIAN NATURAL RUBBER LATEX USING A HYBRID ULTRAVIOLET-PEROXIDE VULCANIZATION METHOD

Abstract

A preliminary study on vulcanized natural rubber latex via hybrid ultraviolet C (UVC) and peroxide vulcanizations was conducted using 2-hydroxy-2-methyl-1-phenylpropanone (Irgacure 1173) as the photoinitiator, 1,6-hexanediol diacrylate (HDDA) and tert-butyl hydroperoxide (t-BHPO) as the sensitizers/coagents. The effects of various amounts of t-BHPO on crosslink density, mechanical and physical properties of UV-peroxide prevulcanized natural rubber latex were investigated and recorded. The tensile strength, modulus at 500% and modulus at 700% elongation of rubber film obtained from one-hour UVC irradiation (temperature within 70-75 ^oC) were 22.0, 3.0 and 9.0 mPa respectively, which is more than 83 % of increment compared to the control sample. The crosslink density of the rubber films showed an increment of 28.5 %.