In order to explore the preparation process of graphene?reinforced composite materials with industrial development prospects, graphene/polypropylene composite materials were prepared using the melt blending method, and the graphene reinforcement mechanism was analyzed through experimental and computational analysis. The results indicate that through melt blending, graphene can be uniformly dispersed in the matrix. The tensile strength of the composite material with a graphene mass fraction of 0.5% is 50.3 MPa. When the mass fraction of graphene is 4.0%, the elastic modulus and tensile strength of the composites are increase by 77.1% and 22.5%, respectively, compared to the polypropylene matrix alone. The uniform dispersion of graphene and the interaction between graphene and the polypropylene matrix enable effective stress transfer at the graphene/polypropylene interface.

The reduction of graphene oxide(GO), in?situ loading of SnSe and interface assembly were achieved simultaneously by microwave method, and the reduced graphene oxide(rGO)?supported the petal?shaped SnSe (SnSe/rGO) composite was successfully prepared. The SnSe/rGO was characterized by Raman spectroscopy, X?ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM), and the effects of different rGO contents for SnSe/rGO composite on the electrocatalytic oxygen reduction reaction(ORR) were investigated. The results indicated that there was an interaction between SnSe and matrix rGO, and Sn-C and Sn-O-C bonds were used as bridges of charge transfer. The intimate interconnection between the petal?like SnSe and the rGO formed a robust three?dimensional mesh structure, which served to reinforce the overall structural integrity of the catalyst, preventing its collapse. Based on this, the optimized SnSe/10%rGO catalyst (10rGO means that the mass fraction of rGO is 10%) exhibited excellent ORR activity with a limiting current density of 3.79 mA/cm², an onset voltage （vs.RHE） of 0.85 V, and an electron transfer number of 3.10. Meanwhile, the SnSe/10%rGO catalyst performed the electrocatalysis long?term stability superior that of commercial 20%Pt/C （20%Pt means that the mass fraction of Pt is 20%） with the current density remaining 81.15% of the start value after 20 000 s of reaction. The present work offers insights into the preparation of non?precious metal cathode oxygen reduction catalytic materials for fuel cells.

The C12-C16 olefin fractions were separated by distillation from coal chemical mixed olefins. The obtained C12-C16 olefins were used as raw materials to synthesize polyalphaolefin (PAO) by AlCl₃ catalyst. The influence of polymerization temperature, polymerization time, polymerization pressure and amount of catalyst were researched. The optimum polymerization conditions were determined. The physical properties of the product were analyzed. The results show that the evaporation temperature of C12-C16 olefins in cold trap oil is 214~274 ℃. Under the conditions of polymerization temperature of 137 ℃, polymerization time of 40 min, polymerization pressure of 4.0 MPa and catalyst mass of 10 g, the polymerization yield is 84.57%, and the kinematic viscosity of obtained PAO product at 40 ℃ is 32.53 mm²/s, the flash point is 221 ℃, the freezing point is -53 ℃, and the bromine value is 9.6 g(Br)/(100 g) .