用动态粘弹函数关系表征PMMA/α-MSAN共混物的相分离

Characterization of the Phase separation in PMMA/ α MSAN Blends Using the Dynamic Viscoelastic Functions

测定了聚甲基丙烯酸甲酯／聚（α－甲基苯乙烯丙烯腈）共混物熔体的动态粘弹性．考察动态储能模量Ｇ′与动态损耗模量Ｇ″的关系，发现在终端区域两种聚合物的ｌｇＧ′～ｌｇＧ″关系曲线与温度无关，其外推直线斜率接近２；而其共混物的斜率明显小于２，并随组成变化呈现温度依赖性，由此得到的“临界温度”可用于表征这种具有ＬＣＳＴ行为的共混物的相容性．

The dynamic viscoelasticity of poly(methyl methacrylate)/poly( α methylstyrene co acrylonitrile)(PMMA/α MSAN) blends in the molten state was measured. By examining the correlation between dynamic storage modulus( G ′) and dynamic lose modulus ( G ″), it was found that for the two components, the plots of lg G ′ vs . lg G ″ show no discernible or a little temperature dependence, and the slopes of the plots in the terminal region approach 2. But for PMMA/ α MSAN blends, the slopes are less than 2, exhibiting temperature dependence relevant to compositions of the blends. By comparing the lg G ′ vs . lg G ″ correlation between the two components and the blends, we obtained so called “critical temperatures( T b)”, which are useful for characterizing the phase separation of PMMA/ α MSAN blends.