酚醛树脂黏度对酚醛/聚氨酯双组份泡沫成型和性能的影响

采用端异氰酸酯聚醚预聚物与可发性酚醛树脂制备了酚醛/聚氨酯泡沫体，通过改变聚合反应时间控制酚醛树脂的结构，研究了可发性酚醛树脂黏度（分子量）对泡沫体成型及性能的影响。结果表明，酚醛树脂黏度大于 2.15 Pa·s 时，泡沫体的体积稳定性好，收缩率低；可发性酚醛树脂分子量增加（树脂黏度从 2.15 Pa·s 增加到 5.05Pa·s）时，泡沫体的密度基本保持稳定；泡沫体弯曲强度达到 0.2 MPa，弯曲应变达到 15 % 以上，远高于纯酚醛泡沫；泡沫体的热稳定性优于聚氨酯泡沫，在 150 ℃ 烘烤 2 h，泡沫体的质量损失为 5 % ～6 %，体积变化为 -5 % 左右；泡沫体密度由 95 kg/m³ 下降到 55 kg/m³ 时，泡沫仍具有很好的韧性和较好的尺寸稳定性。酚醛/聚氨酯泡沫是一种既有很好的热稳定性，同时又具有很好韧性的新型泡沫体材料。

Effect of the viscosity of expandable phenolic resin on the formation process and performance of phenolic/polyurethane foam

A novel heat resistant foam has been prepared using a polyurethane prepolymer with terminal isocyanate groups and expandable phenolic resin.The structure of the expandable phenolic resin was controlled by adjusting the reaction time.The effect of varying the viscosity(molecular weight) of the expandable phenolic resin on the formation process and performance of the foam was investigated.The experimental results showed that the resulting foam had good volume stability and low shrinkage when the viscosity of ...