The effects of polymerization reaction temperature, polymerization reaction time, catalyst and crosslinker addition on the properties of modified ethylene tar pitch (METP) were investigated, and the optimal reaction conditions were obtained by combining elemental analysis, FT?IR, XRD, Raman and thermogravimetric analysis on ETP and METP: The polymerization reaction temperature was 370 ℃, and the polymerization reaction time was 6 h, besides the addition of catalyst and crosslinker was 1.50%. The softening point (SP) of METP obtained under these conditions was 182 ℃, the coking value (CV) was 57.66%, the β resin was 42.26%, and the quinoline insoluble matter (QI) was 0.87%, which met the requirements of high carbon material precursors； The yieid of METP was 73.26%.

The coking kerosene fraction was used as the raw material for the experiment. The linear α?olefins in the raw oil were enriched by complex extraction method, and the high viscosity poly α?olefin base oil (PAO) was synthesized by oligomerization. The effects of temperature, time and catalyst dosage on the properties of PAO were investigated. The kinematic viscosity, viscosity index and PAO yield rate at 100 ℃ were determined. Under the optimum process conditions of catalyst mass fraction of 6%, polymerization temperature of 25 °C, polymerization time of 8.0 h, addition polymerization temperature of 80 °C and addition polymerization time of 2.0 h, the reaction effect is the best: The kinematic viscosity of PAO at 100 ℃ is 43.54 mm²/s, the viscosit index is 163, the freezing point is -50 ℃, and the flash point is 291 ℃. The yield is 85.48%. Compared with the PAO40 standard, the obtained product is a high viscosity lube base oil.

The cold flow property of biodiesel can be effectively improved by pour point depressants (PPD). The terpolymer (AHM) was prepared by solution polymerization of hexadecyl methacrylate, hydroxyethyl methacrylate and maleic anhydride. The effect of AHM on pour point reduction of biodiesel was also investigated. The hexadecyl methacrylate and AHM were characterized by infrared spectroscopy. The optimal reaction conditions of AHM were determined by single factor experiment: n(hexadecyl methacrylate)/n(hydroxyethyl methacrylate)/n(maleic anhydride)=2∶1∶2, the initiator mass fraction is 3.0%, the solvent mass fraction is 65%, the reaction time is 3 h, and the reaction temperature is 85 ℃. When the mass fraction of AHM is 0.7%, the freezing point of biodiesel decreased by 12 ℃. The morphology of wax crystals precipitated from biodiesel at low temperature after adding pour point depressant was observed by polarizing microscope, and the morphology was more uniform and dense.