影响HDPE/PS/PMMA三元体系核壳形态的因素

通过密炼得到高密度聚乙烯(HDPE)、聚苯乙烯(PS)和聚甲基丙烯酸甲酯(PMMA)三元体系核壳结构。用扫描电镜(SEM)考察了组分配比、增容剂氢化苯乙烯-丁二烯-苯乙烯弹性体(SEBS)和退火对体系核壳形态的影响。结果表明,组分用量最大的HDPE总是形成基体相,而PS形成壳,PMMA形成核;核壳粒子的尺寸和内部结构随组分用量而变化,随着分散相用量(PS+PMMA)增加,核壳粒子间碰撞融合机会增多,因此核壳粒子尺寸变大,同时核壳粒子由一核一壳逐渐转变为多核一壳结构;而随着核壳粒子中PS用量增加,PMMA核的尺寸显著减小;增容剂SEBS的加入,抑制了共混中核壳粒子间的融合,导致核和壳的尺寸减小;200℃下退火处理使分散相向体系自由能更小的一核一壳结构转变。

Factors Influencing Core-shell Structure in HDPE/PS/PMMA Ternary Blends

The core-shell structures were produced in high density polyethylene(HDPE)/polystyrene(PS)/polymethyl-methacrylate(PMMA)ternary system using an internal mixer.Factors influencing the core-shell morphology,such as the components content,the addition of compatibilizer of SEBS,and the annealing treatment,were studied.The results showed that,the major component HDPE serves as matrix,PS and PMMA forms the shell and core respectively.The mount and diameter of the core-shell structures increased with the increasing content of dispersed phase(PS+PMMA),this was because of more colliding and coalescence chances in system which possessing more dispersed particles.And the morphology of the dispersed phase tended to change from one core in a shell to many cores in a shell gradually.The diameter of core decreased with the increasing PS content within core-shell particles obviously.The morphology of the dispersed phase tended to be one core in a shell within annealing on account of lower free energy.