Abstract: Basalt fiber (BF) reinforced modified polyurethane composites were prepared using basalt fiber as the reinforcing agent and polyurethane resin as the matrix through pultrusion process. The influences of the content of the fibre and the pulltursion speed on the electrical properties and permeation properties of the basalt fiber (BF) reinforced modified polyurethane composites were systematically studied. And their feasibility was investigated when being used as Ø50 milimeter tonnage composite insulator core in the super/ultra-high line. Under the condition of 300 mm/min of pultrusion speed, 79.7% of fiber content and KH570 as the coupling agent, the PUA/BF showed the most excellent comprehensive performances with good productivity and consistency, which all passed the magenta test. The SEM results show that the PUA had a good adhesion and wetting on the basalt fiber (BF). The electrical property test indicated that the leakage current of composites after being boiled for 100 h were less than 30 μA, which satisfied the insulation requirements of composite insulator core in the super/ultra-high line.

Key words: modified polyurethane, basalt fiber (BF), composites, pultrusion process, magenta test