Department of Chemistry, Natural Product and Polymer Chemistry Laboratory, University of North Bengal, Darjeeling-734 013, West Bengal, India Department of Chemistry, Kokrajhar Govt. College, Kokrajhar-783 370, Assam, India E-mail: pizy12@yahoo.com Manuscript received online 28 October 2020, revised and accepted 31 November 2020 During the last few years, the lubricant industry has given special attention towards the application of vegetable oil based additives for lube oil due to their biocompatibility and enhanced additive performances compared to conventional additives. In this article, the author reported the preparation of homopolymer of rice bran oil (RBO) and copolymers with decylacrylate and alpha pinene at different percentage ratios in the presence of azobisisobutyronitrile (AIBN) as initiator. Characterization of the polymers was recorded by spectral technique (FT-IR and NMR spectroscopy). Gel permeation chromatography method (GPC) was used to determine the average molecular weight of the prepared polymers. Thermo gravimetric analysis (TGA) method was used to study the thermal stability of the prepared polymers at high temperature. Standard ASTM methods was used to investigate the performance of all the prepared polymers in two types of base oil as viscosity index improver (VII) and pour point depressant (PPD). Biodegradability of all the polymers was tested by disc diffusion method and soil burial method.