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Phase- and Interfacial Behavior of hyperbranched aqueous polymer solutions

超支化聚合物水溶液的相和界面行为

基本信息

批准号：
168237187
负责人：
Professorin Dr. Sabine Enders
金额：
--
依托单位：
Institut für Technische Thermodynamik und Kältetechnik (ITTK)
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2010
资助国家：
德国
起止时间：
2009-12-31 至 2015-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/168237187?language=en
关键词：
Phase Interfacial Behavior hyperbranched aqueous

项目摘要

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.

具有树状结构的超支化聚合物是具有大量极性末端基团的强支化、多分散的大分子。基于其独特的性质，讨论了其潜在的应用领域，如用于蒸馏、萃取或二氧化碳捕获的环境友好型溶剂，或作为医药、食品技术和化妆品中的药物输送系统。对于所有这些目的，液-液平衡（LLE）和界面性质起着重要的作用。在最后的研究项目中，基于晶格-簇理论（LCT），结合两种不同的关联模型，建立了一个新的模型来描述超支化聚合物水溶液的脱混行为。实验云点曲线的建模精度令人满意。第一种关联模型将关联描述为强物理相互作用（Wertheim理论），第二种关联模型将关联描述为化学平衡（E-CALM）。这两种缔合模型都能够解释溶剂（通常是水）与聚合物的极性末端基团之间发生的交联，以及溶剂和/或聚合物的自缔合。该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，该模型目前最重要的缺点是忽略了超支化聚合物的多分散性。因此，实际计划的研究项目旨在解决这一问题。首次应用连续热力学理论研究了多分散性对分子量的影响。除了相平衡外，界面性质也是人们关注的焦点。到目前为止，利用密度梯度理论对存在界面的非均匀系统的界面性质进行建模，仅限于三元系统。为了描述多分散聚合物在单一溶剂中的界面特性，应推广这一理论。这一广义理论将使界面富集的研究成为可能，特别是短链聚合物或长链聚合物在界面上优先富集的问题将得到解答。由于大分子量聚合物的高粘度，这个问题的答案对材料在界面上的传递有很大的影响。建立了超支化聚合物水溶液的理论框架。此外，还研究了超支化聚合物与醇（1-丙醇和2-丙醇）组成的溶液的热力学性质。利用这种方法，将详细研究模型的可转移性。