含无规共聚物三元共混体系SMMA-PMMA-SAN相行为

含无规共聚物共混体系的相容性研究正在成为近年来的研究热点 ,因为相容的驱动力来自共聚物分子内不同单体链段间的排斥性相互作用 1～ 3] .目前研究这类体系还主要采用过份简化的 F- H平均场理论 ,用旨在克服平均场理论缺陷的 Flory状态方程 ( EOS)理论仅局限于研究二元共聚物共混体系4～ 8] .与三元共混体系相比 ,用 EOS理论预测含两个无规共聚物三元体系相行为尚需确定共聚物 -共聚物间的二元参数 sj/si,Xij和 Qij.若用 Ax B1- x和 Cy D1- y分别代表共聚物 1和 2 ,则 A,B,C,D代表相应共聚物中的单体单元 ,x,y分别是 1和 2的共…

Studies on the Phase Behavior of Ternary Random Copolymer Blends

A spinodal equation based on the modified Prigogine-Flory′s equation of state theory was derived and applied to predicting the phase behavior of a ternary polymer blend comprising styrene-methyl methacrylate copolymer(SMMA),styrene-acrylonitrile copolymer(SAN)and poly methyl methacrylate(PMMA). According to Flory′s combining rules, the parameters of state equation for copolymers were evaluated from those of the constituent monomer segments, and binary segmental contact energy parameters Xij between copolymer and copolymer were computed. The numerical solution of spinodals of SMMA-PMMA-SAN at various temperatures was derived by computer programming, and confirmed by the corresponding experimental results. It was found that Flory′s equation of state theory could be successfully extended to predict the phase behavior of ternary copolymer blends by adding the term of interaction entropy parameters Q_ij evaluated from the phase diagrams of the corresponding binary blends.