Effect of methacrylate-methacrylamide copolymers with various polar pendants on the cold flow properties of diesel fuels

Abstract

Due to the excellent structural diversity, polymethacrylates was considered as the effective cold flow improvers (CFIs) for diesel. To investigate the structure–activity relationship and obtain more high-efficiency CFIs, a series of methacrylate-methacrylamide copolymers with various pendants (C14MC-BnMAM, C14MC-DpMAM, and C14MC-TrMAM) were synthesized by the radical polymerization of tetradecyl methacrylate (C14MC) with N-benzylmethacrylamide (BnMAM), N-(diphenylmethyl)methacrylamide (DpMAM) and N-(triphenylmethyl) methacrylamide (TrMAM) at various molar ratios. The depressive effects of these CFIs with different benzene ring number on the diesel were tested by cold flow properties. Results illustrated that the overall depressive effects of this three copolymers decrease with increase of the benzene rings number in the side-chain, and the order is as follows: C14MC-BnMAM > C14MC-DpMAM > C14MC-TrMAM As the monomer molar ratio up to 6:1, these CFIs exhibited the largest reduction on the solid point (SP) and cold filter plugging point (CFPP) of diesel. Thereinto, diesel treated with C14MC-BnMAM (6:1) exhibited best depressive effects at the optimal dosage of 2000 ppm, and the SP and CFPP have decreased by 26 °C and 12 °C, respectively. In addition, the performance mechanism of these CFIs in diesel and their low temperature crystallization behaviors were investigated by the rheological behavior, polarizing optical microscope, and differential scanning calorimeter.