羧化聚苯醚与聚苯乙烯共混体系相分离初期分子量影响的光散射研究

 本文用激光光散射方法研究了具有特殊相行为(低临界溶解温度(LCST),高临界溶解温度(UCST)共存]共混体系羧化聚苯醚和聚苯乙烯在UCST域内的不稳相分离初期分子量对动力学参数的影响。结果表明:相分离初期动力学过程与Cahn理论吻合;随着分子量增加,表现扩散系数D_app明显减小;该体系的表现扩散系数为10^-14 cm²s^-1数量级。deGennes管子模型可很好地描述不稳相分离初期大分子扩散行为。

THE EFFECT OF MOLECULAR WEIGHT ON DYNAMICAL PROCESS OF PHASE SEPARATION IN POLYMER BLENDS OF POLYSTYLENE WITH CARBOXYLA-TED POLY (2,6-DIMETHYL PHENYLENE OXIDE)

The effect of molecular weight on dynamical process of spinodal phase separation of po-lystylene(PS) with carboxylated poly(2,6-dimethyl phenylene oxide) (C-PPO) has been investigated by using time resolved light scattering technique. In the early stage, the effect of molecular weight on dynamical parameters of phase separation, such as the growth rate, R(q) of phase se paration and apparent diffusion coefficient, are distinct, As the molecular weight increasing, the apparent diffusion coefficient, D_app,decreases. Experimental results obtained from three mixtures tend to support the relationship of q²_m/D_app proportional to the degree of po-lymerization (N),and the diffusion behaviour coincides the reptation mechanism.