两亲聚氨酯弹性体(APU)的研究IV.嵌段型APU表征及透湿性能

讨论以聚乙二醇为亲水软段 ,聚己二酸乙二酯为疏水软段的嵌段型 APU(BAPU)的结构表征及其透湿性能。用调制温度示差扫描量热分析方法研究了 BAPU的玻璃化转变 ,发现具有混合软段 BAPU的玻璃化转变温度和热容增量均介于纯亲水和纯疏水性软段 BAPU的相应值之间 ,透湿性能测定证明 ,BAPU的透湿系数随其亲水性及交联密度显著变化     

多壁碳纳米管对苯并口恶嗪树脂固化反应的影响

苯并口恶嗪树脂作为新的热固性材料需要较高的温度进行凝胶和固化。碳纳米管可以催化苯并口恶嗪树脂的固化反应。文中采用差示扫描量热仪(DSC)通过动态DSC分析及恒温DSC分析研究了不同质量分数的碳纳米管对苯并口恶嗪树脂固化的催化效果。结果表明,加入过量的纳米管会导致反应活化能和指前因子增加,这意味着其阻碍了固化反应。2%的碳纳米管对苯并口恶嗪树脂固化有最好的催化效果,表现为固化的活化能由275.83 kJ/mol降至51.97 kJ/mol。     

PMMA／PSAN共聚物混合体系不稳相分离的中,后期特征

The intermediate to later stage of the spinodal decomposition of off-critical mixture of poly (methyl methacryate) ( PMMA ) and poly ( styrene-co-acryonitrile ) ( PSAN) was investigated by the time-resolved light-scattering technique.lt is shown that during unmixing process there exist power relations of maximum scattered intensity Im(t)and its corresponding wave vactor to time t. In the later stage the scaling relation of structure funcfion S (q, t) with wave vactor qm and β=3α were found. In the intermediate stage some relationship of structure function S(q,t) with wave vactor q was revealed.     

两亲聚氨酯弹性体(APU)的研究Ⅳ.嵌段型APU表征及透湿性能

讨论以聚乙二醇为亲水软段，聚已二酸乙二酯为疏 软段的嵌段型ＡＰＵ（ＢＡＰＵ）的结构表征及其透湿性能，用调制温度示差扫描量热分析方法研究了ＢＡＰＵ的玻璃化转变，发现具有混合软段ＢＡＰＵ的玻璃化转变温度和热容增量均介于纯亲水和纯疏水性软段ＢＡＰＵ的相应值之间，透湿性能测定证明，ＢＡＰＵ的透湿系数随其亲水性及交联密度显著变化。