Effect of Heteroaromatic Pendants in Comb Copolymers on Paraffin Crystallization and Cold Flow Ability of Crude Oil

Abstract

Adding comb copolymers as chemical additives is considered an effective and convenient method to improve the cold flow ability of crude oils. To improve the effectiveness of comb copolymers on the flow ability modification for crude oils with asphaltenes, poly(maleic acid amide-α-octadecene) with benzimidazolyl pendants (MACB) were designed and synthesized. In comparison to reported comb maleic anhydride copolymers (MAC) with octadecyl (MACO) or phenyl (MACP) pendants, MACB with heteroaromatic pendants are more efficient in reducing the yield stress of both model oil and Liaohe crude oil, as revealed by rheological measurements, in modifying the morphology of wax crystals, as observed by polarizing light microscopy (PLM), in lowering the wax appearance temperature (WAT) and quantity of wax precipitation, as determined by differential scanning calorimetry (DSC), and in decreasing the crystallinity of paraffins, as measured by X-ray diffraction (XRD). The benzimidazolyl pendants in MACB can provide both hyd...