ZulfansyahIwan Fermi, MuhammadMaa Rasyid, Cici2013-05-042013-05-042013-05-04978-602-967-0-9wahyu sari yenihttp://repository.unri.ac.id:80/handle/123456789/3164Response surface method was used for the evaluation of the effects of various factors on the synthesis of biodiesel from rubber seed oil with sodium hydroxide as the catalyst. The production of biodiesel was optimized and model response equation was obtained, and able to predict the biodiesel production from the values of the three main factors. It would seem that the catalyst concentration and oil/methanol ratio predominatly determined the reaction convertion, while the reaction temperature had no significant effect on the yield of biodiesel. The catalyst concentration and oil/methanol ratio showed positive effects on the perolehan of biodiesel. However, there were no significant interactions among the variables according to test of statistic significance. The yield of biodiesel product predicted at the optimum condition was 86%. Finally, biodiesel from rubber seed oil at the optimum condition has density of 882 kg/m3, kinematic viscosity at 40oC was 7.70 mm2/s, flash point at 23oC, cetane number was 62,06 and acid value was 0,16 mg KOH/g.enBiodieselrubber seed oilRSMesterificationsUR-Proceedings