A new trend in radiation vulcanization of natural rubber latex with a low energy electron beam

Abstract

The natural rubber latex (NRL) was radiation vulcanized under a pilot plant of low energy electron accelerator. Accelerating voltage and maximum beam current of this accelerator are 250 kV and 10mA respectively. Irradiation on NRL was carried out in a reaction vessel with constant stirring. In order to obtain a suitable setting of experiment for radiation vulcanization with the plant, the parameters such as defoamer concentration, irradiation time, volume of latex, beam current, latex concentration etc. were optimized by varying the individual parameter at a constant set of the other variables. Radiation vulcanization accelerators (RVA) were normal butyl acrylate (n-BA) and nonane-diol-diacrylate (NDDA). Twenty minutes irradiation time is enough to vulcanize 14 L of latex when 5phr RVA (any type) are used. Maximum tensile strength of the radiation vulcanized NRL films obtained with 5 phr of NDDA or n-BA is ∼26 MPa. About 30 MPa tensile strength was obtained from the rubber film by irradiating 25% diluted latex for 20min.