Krisda SuchivaChyagrit Siri-UpathumJindarom ChvajarernpunKulthida Vongbupnimit2023-10-192023-10-19199219922023Thesis (M.Sc. (Polymer Science))--Mahidol University, 1992https://repository.li.mahidol.ac.th/handle/20.500.14594/90531Various factors affecting the properties of gamma radiation vulcanised natural rubber latex (RVNRL) were studied. The objective was to help develop the technology of RVNRL in Thailand. Thus, the effects of irradiation conditions, film formation conditions and the quality of the latex were studies. Characterisation of RVNRL cross linked with carbon tetrachloride/n-butyl acrylate as sensitiser were made. Also studied were the sensitising effect of radical initiators (benzoyl peroxide, azo-bisisobut and t-butylhydroperoxide)/chloroform or isoprene combination. The results showed that good RVNRL properties could be obtained from 50% (DRC) concentrated latex, irradiated at room temperature without having to stir. RVNRL samples had to be leached in water.at 60 Degree C for 1 hour and dried at 60 C for 30 minutes. Humidity has a significant effect in lowering properties of RVNRL film and therefore must be carefully controlled. Application of pressure to RVNRL film sample does not help improve their properties. No anisotropic effect was observed in RVNRL sample casted from the latex. RVNRL samples prepared by using carbon tetrachloride and n-butyl acrylate as sensitiser contained 6.3 % by weight of uncross linked rubber. The crosslink density was 4.8x10(-5) mole/g of rubber at 12 kGy dose. Crosslinks in these RVNRL samples are probably poly(n-butyl acrylate) type and not carbon-carbon crosslinks. The average particle size of natural rubber in the latex was observed to increase slightly from 0.79 um to 0.86 um after compounding and irradiation. Study of sensitiser system showed that t-butylhydroperoxide/chloroform combination could provide alternative sensitiser system to carbon tetrachloride/n-butyl acrylate system presently being used. Isoprene showed poor sensitising effect for RVNRL despite the aids of various radical initiators studied.xix, 173 leaves : ill.application/pdfengRubberVulcanizationMahidol University