Key Laboratory for Polymeric Composite and Functional Materials of Ministry of Education, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275, PR China.
Phys Chem Chem Phys. 2010 Mar 7;12(9):2238-45. doi: 10.1039/b918069a. Epub 2010 Jan 19.
In this work, kinetics of phase separation in the blends of polystyrene (PS) and poly(vinyl methyl ether) (PVME) was investigated by a simple and sensitive method, i.e., resonance light scattering (RLS) spectroscopy. Owing to the aggregation of chromophores (phenyl rings) in the systems when phase separation occurred, RLS intensities were drastically enhanced and hence acted as a characteristic indicator. At the early stage of phase separation, two different RLS behaviors corresponding to spinodal decomposition (SD) and nucleation and growth (NG) were observed. The Cahn-Hilliard (C-H) linearization theory was found not applicable for kinetics analysis of the scattering data at lambda < 346 nm due to RLS effect near the absorption band. Based on a decomposition reaction model, the apparent activation energy of SD phase separation was estimated by the Arrhenius equation. In view of its simplicity and sensitivity of measurement, affordability and availability of instrument, and wide application range of polymer blends, RLS proved to be an effective means for characterization of microstructural variation in polymer blends.
在这项工作中，通过一种简单而灵敏的方法，即共振光散射（RLS）光谱法，研究了聚苯乙烯（PS）和聚（甲基乙烯基醚）（PVME）共混物中的相分离动力学。由于体系中发色团（苯环）在发生相分离时聚集，RLS 强度大大增强，因此成为一个特征指标。在相分离的早期阶段，观察到两种不同的 RLS 行为，分别对应于旋节分解（SD）和成核与生长（NG）。由于在吸收带附近存在 RLS 效应，Cahn-Hilliard（C-H）线性化理论不适用于在 lambda < 346nm 时对散射数据的动力学分析。基于分解反应模型，通过阿仑尼乌斯方程估算了 SD 相分离的表观活化能。鉴于 RLS 具有测量简单灵敏、仪器经济实用、适用范围广泛等优点，证明它是研究聚合物共混物微结构变化的有效手段。
