【摘要】 利用动态热机械分析研究了阻燃剂含量不同的一组聚氨酯的动态力学性能;根据"时间-温度"等效原理的W LF方程获得了该聚氨酯系列α松弛的黏弹系数Cg1、C2g和主曲线叠合的垂直位移因子bT以及松弛过程的活化能Ea。结果表明,适量(质量分数10%)三聚氰胺磷酸盐阻燃剂使Pu-2聚氨酯包覆层的低温储能模量E′有大幅度提高,α松弛的tanδ峰值强度和峰面积随阻燃剂含量的增加而下降,但低温时E′随阻燃剂含量的继续增加而下降,α松弛的tanδ峰温(即玻璃化温度Tg)也随之下降。根据Cg1、Cg2、bT和Ea有规律的变化,用自由体积理论和bT与体系密度的关系解释了阻燃剂的加入对聚氨酯动态力学性能的影响。结果表明,适量的三聚氰胺磷酸盐阻燃剂除具有"补强"作用外,还具有增塑作用,同时随着阻燃剂含量的增加,这种增塑作用占主导地位。更多还原

【Abstract】 The dynamic mechanical properties of a series of polyurethane with various contents of the deterrent were characterized by using a dynamic mechanical analyzer.The viscoelastic coefficients Cg1,Cg2 and the activation energy Ea on the α-relaxation transition of the polyurethanes were obtained according to the time-temperature equivalence principle.The results showed that appropriate content(10%) of melamine phosphate deterrent made the storage modulus E′ increase enormously at low temperature.With increase of the deterrent,the peak value and area for tanδ on the α-relaxation became lower;then the E′ at low temperature and the peak temperatures(i.e.glass transition temperature Tg) for tanδ on the α-relaxation decreased as the continued increase of deterrent contents.On the basis of inerratic change of the Cg1,Cg2,bT and Ea of the α-relaxation,the influence of the deterrent on the dynamic mechanical properties of polyurethane was explained by the free volume theory and the relation for bT and system density.It is shown that the appropriate content of the deterrent not only have the reinforce effect but also has plasticization agent effect.At the same time,the plasticization effect becomes more dominant with the increase of the deterrent content.更多还原