Molecular Rheology of Miscible Polymer Blends

本研究是对相异聚合物共混物在纠缠流体状态下的粘弹性进行的实验和理论研究。首先将由分子量分布窄、微观结构可变的具有良好特性的线型聚丁二烯制备二元共混物。这些混合物的杂聚特性将通过增加参与组分中乙烯基含量的差异来控制。动态振荡实验、稳态剪切实验、拉伸实验和阶跃应变实验将被用来研究这些体系在不同温度下的线性和非线性粘弹性作为组成的函数。因此，混合物的流动性、弹性和刚性将与其纯成分的相应性质有关。还将对商业聚合物的混合物进行调查，以测试对模型聚合物混合物得出的结论是否适用于商业利益的案例。特别强调的是共混物中，由于存在强烈的特定相互作用而导致的混相性。用来解释可混溶杂聚共混物中的复合网络结构和分子动力学的分子理论将被扩展以适应非理想行为。这项研究是更好地了解不同聚合物混合行为的一般形式的一部分。颗粒的结果将是更有效地处理回收塑料，这些塑料通常是混合物。

This research is an experimental and theoretical study on the viscoelastic properties of blends of dissimilar polymers in the entangled fluid state. Binary blends will first be prepared from well-characterized linear polybutadienes of narrow molecular-weight distribution and variable microstructure. The heteropolymer character of these mixtures will be controlled by increasing the disparity of the vinyl group content in the participating components. Dynamic-oscillatory, steady-shear, tensile, and step- strain experiments will be utilized in examining the linear and nonlinear viscoelasticity of these systems at several temperatures as a function of composition. The fluidity, elasticity, and rigidity of a blend will thus be related to the corresponding properties of its pure constituents. Blends of commercial polymers will also be investigated to test whether the conclusions drawn on model polymer mixtures apply to cases of commerical interest. Especial emphasis will be given on blends where miscibility is driven by the presence of strong specific interactions. A molecular theory already developed to explain the composite network architecture and molecular dynamics in miscible heteropolymer blends will be extended to accommodate non-ideal behavior. This research is part of a general format to understand better the mixing behavior of dissimilar polymer. A particle outcome would be more efficient processing of recycled plastics, which are typically mixtures.