Phase- and Interfacial Behavior of hyperbranched aqueous polymer solutions

超支化聚合物是一种具有树枝状结构的高度支化、多分散的大分子，具有大量的极性端基。基于其独特的性质，讨论了几个潜在的应用领域，如用于蒸馏、萃取或CO2捕集的环境友好溶剂，或作为药物递送系统在医学、食品技术和化妆品中。对于所有这些目的，液-液平衡（LLE）以及界面性质起着重要作用。在最后一个研究项目中，一个新的模型的基础上的晶格簇理论（LCT）结合两种不同的缔合模型的描述超支化聚合物水溶液的分层行为的开发。实验结果表明，该模型能较好地拟合实验浊点曲线.第一个缔合模型描述了强物理相互作用（Wertheim理论）和第二个化学平衡（E-CALM）的协会。两种缔合模型都能够解释溶剂（通常为水）与聚合物的极性端基之间发生的交叉缔合以及溶剂和/或聚合物的自缔合。组合模型允许在热力学方程中直接使用聚合物结构，而无需任何额外的可调参数。然而，在其目前的状态下，该模型的最重要的缺点是超支化聚合物的多分散性的忽略。因此，实际预定的研究项目旨在解决这一问题。首次从理论上研究了连续热力学条件下多分散性对分子量的影响。除了相平衡之外，界面性质也是感兴趣的焦点。到目前为止，界面性质的建模与密度梯度理论的帮助下，非均相系统，其中界面存在，仅限于三元系统。为了更好地描述多分散聚合物在单一溶剂中的界面性质，该理论还需进一步推广。这一广义理论将允许界面富集的研究，特别是问题，如果短链聚合物或长链聚合物将优先富集在界面将得到回答。由具有大分子量的聚合物的高粘度引起，该问题的答案对界面上的材料转移具有很大的影响。理论框架将发展为超支化聚合物水溶液。此外，超支化聚合物和醇（1-丙醇和2-丙醇）组成的溶液的热力学性质将被研究。使用这种方法的模型的可转移性将进行详细研究。

Hyperbranched polymers with a tree-like structure are strongly branched, polydisperse macromolecules with a large number of polar terminal groups. Based on their unique properties several potential application areas, such as environment-friendly solvent for distillation, extraction or CO2-capture or as drug-delivery system in medicine, in food technology and in cosmetics are discussed. For all of these purposes the liquid-liquid equilibria (LLE) as well as the interfacial properties play an important role. In the last research project a new model based on Lattice-Cluster-Theory (LCT) in combination with two different association models for the description of the demixing behavior of aqueous hyperbranched polymer solutions was developed. The experimental cloud point curve could by modeled with satisfactory accuracy. The first association model describes the association as strong physical interaction (Wertheim theory) and the second one as chemical equilibrium (E-CALM). Both association models are able to account for cross association occurring between the solvent, usually water, and the polar terminal groups of the polymer and the self-association of the solvent and/or the polymer. The combined model allows the direct use of the polymer architecture in the thermodynamic equations without any additionally adjustable parameter. However, the most important disadvantage of the model in its current state is the negligence of the polydispersity of the hyperbranched polymer. Therefore, the actual scheduled research project aims to solve this issue. To the first time the influence of the polydispersity with respect to the molecular weight using continuous thermodynamics should by investigated theoretically. Beside to the phase equilibria also the interfacial properties are in focus of interest. Until now, the modeling of interfacial properties with help of the density gradient theory for inhomogeneous systems, where an interface is present, is limited to ternary systems. The theory should be generalizes in order to describe the interfacial properties of polydisperse polymers in a single solvent. This generalized theory will permit the study of interfacial enrichment, especially the question, if short-chain polymers or long-chain polymers will be preferential enriched in the interface will be answered. Caused by the high viscosity of polymers having a large molecular weight the answer of this question has a large impact on the material transfer over the interface. The theoretical frameworks will be developed for aqueous hyperbranched polymer solution. Additionally, the thermodynamic properties of solution composed of hyperbranched polymers and alcohol (1-propanol and 2-propanol) will be investigated. Using this approach the transferability of the models will be investigated in detail.