Molecular investigation of the swelling behaviour of polymer model networks

该项目包括两个部分，分别专注于更好地理解聚合物网络中的缠结和可逆键。在项目的第一部分，应该为仅由缠结组成的理想网络的变形建立一个合适的模型。这是基于滑管模型、之前关于奥林匹克凝胶膨胀的结果，以及当前项目提供的关于理想滑环凝胶和奥林匹克凝胶变形和膨胀的额外模拟数据。为了更好地理解这些网络的弹性、缠结之间的相互作用以及环糊精在膨胀和变形过程中沿链的受限扩散，需要将该缠结网络模型扩展到含有大量环糊精的实际滑环凝胶中。为此，结和缠结对膨胀和变形的非亲和性的相互影响应该使用一系列的奥林匹克凝胶和/或滑动环凝胶增加额外的共价交联量进行研究。这些研究的目标是，为传统聚合物网络的变形和膨胀的非仿射贡献开发一个定量模型。在项目的第二部分中，将扩展可逆键的重组动力学理论，纳入应力引起的键断裂和缠结网络。部分可逆模型网络的变形和能量耗散模拟的目标是量化由于断裂键导致的集体重排和应力松弛，并为这一过程建立模型。分子构建块的结构对部分可逆网络弛豫的影响应使用两类模型网络（沿着结之间的链和星形臂或支链聚合物末端的贴纸）进行分析和理解。

The project consists of two parts that focus on a better understanding of entanglements and reversible bonds in polymer networks, respectively.In the first part of the project, a suitable model shall be developed for the deformation of ideal networks that consist solely of entanglements. Thiss occurs based upon slip tube models, preceeding results on the swelling of Olympic gels, and additional simulation data on the deformation and swelling of ideal slide-ring gels and Olympic gels, which are contributed by the current project. This model for networks of entanglements shall be extended to model real slide-ring gels with a multitude of cyclodextrine in order to better understand the elasticity of these networks and the interplay of entanglements and the confined diffusion of cyclodextrine along the chains during swelling and deformation. To this end, the mutual influence of junctions and entanglements on the non-affinity of swelling and deformation should be investigated using a series of Olympic gels and/or slide-ring gels with an increasing amount of additional covalent cross-links. It is the goal of these investigations, to develop a quantitative model also for the non-affine contributions to deformation and swelling of conventional polymer networks.The theory about the recombination dynamics of reversible bonds shall be extended in the second part of the project to incorporate stress-induced breakage of bonds and entangled networks. The simulation of the deformation and energy dissipation of partially reversible model-networks has the goal to quantify the collective rearrangements and stress relaxation in consequence of a breaking bond and to develop a model for this process. The impact of the architecture of the molecular building blocks on the relaxation of partially reversible networks shall be analyzed and understood using two classes of model networks (stickers along the chains between junctions and stickers on the ends of star arms or branched polymers).