Some of the factors that control the efficiency of vulcanisation of NR latex by gamma irradiation are initial molecular weight of rubber, green strength of rubber and the amount of non -rubber ingredients present . Generally latex concentrate is stored for about three weeks to achieve an improvement in molecular weight and hence green strength. In this work an attempt is made to improve gel content of fresh NR latex by exposure to low doses of gamma radiation followed by centrifuging and creaming of latex to reduce the non-rubber ingredients. The concentrated latex is then vulcanised by exposure to gamma radiation in presence of n-butyl acrylate as sensitiser.lt is observed that on exposure of fresh NR latex to low doses of gamma radiation there is an increase in gel content favouring enhanced level of vulcanisation. RVNRL prepared by prior irradiation with gamma radiation has very good mechanical properties. It is observed that RVNRL could be more easily blended with synthetic latex because there is formation of graft copolymer and an enhancement in colloidal stability after irradiation. On blending RVNRL with high styrene content styrene butadiene copolymer latex (HSBL) the modulus increase depending on its concentration mainly due to the rigidity of rubber presentRVNRL of improved mechanical properties are obtained by using concentrated NR latex that has higher gel content and by blending RVNRL with HSBL.
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