摘要
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2.15Pa.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2.15Pa.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。
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 the phenolic resin was more than 2.15Pa·s.With increasing molecular weight of the expandable phenolic resin（equal to the viscosity increasing from 2.15 to 5.05Pa·s）,the density of the foam stabilized between 60.16 and 63.96kg/m3.The bending strength of the novel foam reached 0.2MPa,and bending strain was more than 15%,much better than the corresponding values for pure phenolic foam;The mass loss of the foam was 5%-6%,and the volume decrease was about 5% when the foam was heated at 150℃ for 2h,indicative of good thermal stability.When the density decreased from 95 to 55kg/m3,the foam still maintained good toughness and good dimensional stability.The novel phenolic/polyurethane foam therefore has better thermal stability than polyurethane foam and better toughness than phenolic resin foam.
出处
《北京化工大学学报（自然科学版）》
CAS
CSCD
北大核心
2011年第2期52-57,共6页
Journal of Beijing University of Chemical Technology(Natural Science Edition)
基金
国家"863"计划(2007AA03Z559)
关键词
酚醛/聚氨酯泡沫
黏度
成型时间
弯曲应变
耐热性
phenolic/polyurethane foam
viscosity
forming time
bending strain
heat resistanc
