Exploring Polymer Dynamics in Solutions and Blends

系统的研究将阐明A/B共混物中A和B的组分动力学如何取决于温度和成分，即揭示与A和B相关的摩擦因子如何随温度和成分变化，并确定A和B是否在显著不同的温度下经历玻璃化转变。聚合物塑化的概念尚未被证明是在聚合物组分具有显着不同温度的溶液中观察到的负特性粘度的起源。聚合物a在溶液或混合物中的动力学是否完全由链间（外在）相互作用决定，还是受到链内（内在）相互作用的进一步影响，从而与B的相互作用不同，以及a是否在不同的温度下经历玻璃化转变，这仍然是一个基本问题。一种新颖的溶液流变学方法（SRA）将被应用于探索这些主题。为了描述在混相共混物（例如，由A和B组成）中运行的单独组分动力学，将分别研究相应的“对象”和“镜像”溶液（例如，由聚合物A在低聚物B和聚合物B在低聚物A组成），以解决A和B的组分动力学。研究溶液动力学以获得有关相应共混物组分动力学的明确信息的方案代表了该主题的一个新的有吸引力的方法。很少有实验技术成功有效地应用于此。这种SRA的优点是能够以最小的浓度波动确定组分动力学，并探测非混相共混物中的组分动力学。所提议的研究的目标是在与聚合物材料流变学和加工有关的溶液和共混物中实现对聚合物动力学的新理解。本课题是高分子科学与工程的核心，也是高分子材料研究的一个非常活跃的领域。一个核心问题是如何在了解每个组分的玻璃化转变和粘弹性特性的情况下预测分子混合聚合物共混物的整体粘弹性和单个组分动力学。

Systematic work will be carried out to elucidate how the component dynamics of A and B in a miscible A/B blend depend differently on temperature and composition, i.e., to uncover how friction factors associated with A and B each vary with the temperature and composition, and to determine whether A and B experience glass transition at significantly different temperatures. The concept of polymer plasticization is yet to proven as the origin of the negative intrinsic viscosity observed in solutions where the polymer component has a significantly different temperatures. It remains a fundamental question whether dynamics of polymer A in a solution or blend depend are completely determined by inter-chain (extrinsic) interactions or are further influenced by intra-chain (intrinsic) interaction so that they are from those of B and whether A undergoes the glass transition at a different temperature from that where B experiences its glass transition.. A novel Solution Rheology Approach (SRA) will be applied to probe these topics. To depict the separate component dynamics operative in miscible blends (e.g., made of species A and B), corresponding "object" and "mirror" solutions (e.g., made of polymeric A in oligomeric B and polymeric B in oligomeric A) will be investigated respectively to resolve the component dynamics of A and B. The protocol studying solution dynamics to gain explicit information about the component dynamics of corresponding blends represents a new attractive approach to the subject, to which few experimental techniques have been successfully and effectively applied. This SRA has the advantage of being able to determine the component dynamics with minimal concentration fluctuations as well as to probe component dynamics in immiscible blends.%%%The objective of the proposed research is to achieve new understanding of polymer dynamics in solutions and blends that are pertinent to rheology and processing of polymeric materials. The subject of the proposed work is at the heart of polymer science and engineering and is a very active area of polymer materials research. One central question is how to predict the overall viscoelasticity and individual component dynamics of a molecularly mixed polymer blend knowing the glass transition and viscoelastic properties of each component.