接枝纳米填料在部分相容聚合物共混物基体中的选择性分布调控及其对基体相形态结构的影响

Based on the obtained preliminary results, one component in a partially miscible polymer blend will be selected as the graft polymer of nano-fillers. The interaction between the graft polymer and chemically identical polymer in the blend matrix will be controlled by changing its graft density and molecular weight. There also exists some special interaction between the other component of blend matrix and the graft polymer and the competition from such two interactions will facilitate the achievement for the controllable, stable distribution of nanoparticles in the blend matrix. The selective distribution and dispersion-aggregation state of modified nanoparticles in the partially miscible blend matrix and the influence of its selective distribution on the molecular dynamics, the thermodynamics and kinetics of phase separation and the morphology evolution for the blend matrix will be probed via a combination of electron microscope, rheological measurement, small angle laser light scattering (SALLS) and broadband dielectric spectroscopy. The phase diagram for the stable dispersion of grafted nanoparticles in the blend matrix will be depicted and the cause for the selective distribution of modified nanoparticles in the blend matrix will be elucidated. Furthermore, the correlation between the selective distribution of modified nanoparticles and morphology of blend matrix for ternary polymeric nanocomposites will be established, which will provide a theoretical guidance for the development and preparation of polymeric nanocomposites with high filler loading, uniform dispersion, stable controllable morphology and structure.

本申请项目拟以申请者已有的初步结果为基础，以共混物基体中的一组分作为纳米填料的接枝聚合物，通过改变接枝密度和链长调节接枝聚合物和基体中同种聚合物间的相互作用，而另一组分与接枝聚合物间的特殊相互作用则与之相竞争，从而实现填料在共混物基体中的可控稳定分布。拟借助电子显微镜、流变学、小角激光光散射和宽频介电谱等手段，考察填料在部分相容共混物基体中选择性分布和分散-聚集状态并给出其在共混物基体中稳定分布的相图，探明改性纳米填料的选择性分布对共混物基体的分子动力学、相分离热力学、动力学及相形态演变的影响规律，阐明接枝改性纳米填料在共混物基体中发生选择性分布的诱因及其对聚合物分子动力学和宏观相分离动力学影响间的关联，建立聚合物基三元纳米复合材料的填料选择性分布-基体相形态间的关系，为设计和制备高填充量、均匀分散且具有稳定可控相形态结构的聚合物基纳米复合材料并实现其功能化应用提供理论指导。

共混和填充改性是改善高分子材料性能、赋予新功能及降低成本的有效方法。而纳米粒子（NPs）在非均相共混基体中的选择性分布和均匀分散，极大地影响复合材料的形态结构，进而影响其最终性能与应用。对 NPs 进行接枝改性可改变其与共混基体组分间的相互作用，有望实现对其在共混基体中选择性分布的调控；而阐明接枝改性 NPs 在共混基体中选择性分布机理，将有助于制备具有可控相形态结构和 NPs 分布的聚合物基纳米复合材料。本项目借助电子显微镜、小角激光光散射等手段，采用可控聚合法在几种纳米粒子NPs（二氧化硅SiO2、多壁碳纳米管MWNTs、蒙脱土Clay等）表面接枝了不同链长、密度的均聚物，考察改性NPs在共混基体中的选择性分布，建立了可预测均聚物接枝NPs在不同共混基体中热力学稳定分布的相图，实现了对NPs在不同共混基体中热力学稳定分布的调控；研究了NPs的团聚体对其与基体浸润系数及选择性分布的影响，用Wenzel粗糙度修正传统浸润系数公式可解释并预测了NPs聚集状态对其在共混基体中选择性分布的影响；探明了不同NPs在基体中的选择性分布和迁移对共混基体相分离行为的阻碍作用，建立了聚合物基三元纳米复合材料的填料选择性分布-基体相形态间的关联，为制备高填充量、均匀分散且具有稳定可控相形态结构的聚合物基纳米复合材料提供了理论指导。