Synthesis and characterization of natural rubber copolymers and maleic anhydride as pour points depressant in crude oil

Abstract

Crude oil contains high paraffin which may deposited on pipelines below pour point temperature. Therefore, pour point depressant (PPD) is required to prevent precipitation. Copolymerization of deproteinized natural rubber with maleic anhydride has been synthesizedwith variation of 70:30 and 60:40. The success of PPD synthesis was evaluated based on graft efficiency, graft ratio, and infrared spectra. The characteristic of interaction between components in the copolymer additives was evaluated using Fourier transformed infrared spectrophotometer. The presence of absorption at wavenumber 1748 cm-1 shows C=O stretch in maleic anhydride ring and the absorption at 764 cm-1 showed the presence of C=C stretch of maleic anhydride grafted. The PPD of 70:30 was able to decrease the pour point of crude oil until 12 C with concentration 10000 ppm. The PPD is also able to change the paraffin crystals shape become smaller and scattered, and reduce the kinematic viscosity of crude oil as well.