关键词: 酚醛泡沫, 聚氨酯预聚体, 抗粉化, 导热性

Abstract: The toughening phenolic foam with low pulverization was prepared by adding polyurethane prepolymer which is terminated with isocyanate and without free isocyanate monomer, and by reducing the consumption of acidic curing agent in the foaming process. The effect of isocyanate content on the apparent density, compressive strength, water intake, flame retardant and heat conductivity of phenolic foam were also discussed. The results showed that the apparent density and compressive strength of the modified phenolic foam tended to increase with the content of polyurethane prepolymer and corresponding isocyanate group. Meanwhile, the resistance to pulverization is the best when the isocyanate content is 8.6%. However, the water absorption and heat conductivity of the modified polyurethane foam changed little with the increase of polyurethane prepolymer. The critical oxygen index was still more than 40 when the content of polyurethane was less than 6%.

Key words: phenolic foam, polyurethane prepolymer, resistance to pulverization, heat conduction