Improving Cold Flowability of High Waxy Crude Oil by Comb‐Type Polymer Prepared From Green Biomass

ABSTRACT In this study, poly(octadecyl acrylate‐co‐maleic anhydride) (POM) was synthesized via reversible addition–fragmentation chain transfer (RAFT) polymerization, followed by grafting green biomass with maleic anhydride. The chemical structures of the synthesized polymers were characterized by Fourier transform infrared spectroscopy (FT‐IR), Proton nuclear magnetic resonance ( 1 H NMR), and Gel permeation chromatography (GPC). The effects of these polymers on the crystallization behavior and cold flowability of waxy crude oil were examined using X‐ray diffraction (XRD), differential scanning calorimetry (DSC), polarized light microscopy, and rheological analysis. Addition of octadecyl acrylate‐maleic anhydride glyceryl monostearate (OM‐GMS) the crystallization activation energy increasing largely from 1.422 to 8.420 kJ mol −1 . When POM was grafted with saturated fatty acids, the crystallinity index ( CI ) decreased by 4.14% compared to unsaturated fatty acids. Viscosity first decreased by 95.4% with OM‐GMS addition, then increased with more long‐chain alkanes in glyceride. Viscosity first decreased and then increased with increasing grafting rate. At a grafting ratio of 0.4, viscosity decreased by 93.4%. Incorporating green biomass into polymer design is recommended to further reduce reliance on fossil fuels. Future efforts should prioritize replacing conventional monomers in pour point depressants with sustainable biomass‐based alternatives, enhancing crude oil flowability while advancing environmental stewardship.