基于动态共价键的多重刺激响应性超分子树枝化聚合物的可控构筑及应用研究

Multi-stimuli responsive supramolecular dendronized polymers are firstly fabricated based on dynamic covalent bonds in this research. Multi-stimuli responsive supramolecular dendronized polymers can be fabricated by self-assembly of different stimuli resposive dendrons with aldehyde groups and the polymers with amino groups in the side-chain. For the different stimuli-resposive dendrons, there are thermo-resposive dendrons and photo-resposive dendrons, respectively. For the polymers with amino groups, they include poly (2-(4-aminophenoxy) ethyl methacrylate) with flexible main-chain and hydroxyethyl chitosan with semi-rigid main-chain. The effect of the factors, such as chemical structures of dendrons, mole ratio of between different dendrons, structure of main chain, mole ratio of aldehyde group to amino group, concentration, temperature, pH and photo, etc., on stimuli-responsive behaviors of these polymers will be investigated. Comparison of the effect of main-chain structures on stimuli-responsive behaviors, the mechanisms of stimuli responsiveness will be further investigated. Based on the above research findings, the applications of multi-stimuli responsive supramolecular dendronized polymers in the tunable LCST, lytropic liquid crystals and sensor will be studied. We hope that the results obtained may provide new theoretical basis and application technology for the field of biotechnology and environmental monitoring technology, and can enrich and develop the theoretical research and application area of multi-stimuli responsive supramolecular.

本项目拟采用动态共价键可控构筑多重刺激响应性超分子树枝化聚合物。将不同环境刺激响应性树枝化基元（温度敏感、光敏感等）与侧链带有氨基的高分子（包括具有柔性主链结构的聚（2-（4-氨基苯氧基）甲基丙烯酸乙酯）和具有半刚性主链结构的天然高分子壳聚糖）进行动态共价键自组装，可控构筑多重刺激响应性超分子树枝化聚合物。研究温敏性树枝化基元和光敏基团的结构和比例、主链结构、醛基/氨基比例、浓度、温度、pH值、光等因素对聚合物刺激响应行为的影响；通过对比考察主链构象对刺激响应行为的影响，进而深入研究多重刺激响应机理。在此基础上，开展对多重刺激响应性超分子树枝化聚合物的应用研究。通过对此类聚合物的 LCST可控调控，壳聚糖溶致液晶和传感器方面的应用探索，以期为生物技术、环境监测技术等领域提供新的理论依据和应用技术，丰富和发展多重刺激响应性超分子和智能树枝化高分子的理论研究和应用领域。

多重刺激响应性聚合物是指一类对于多种环境的刺激或者变化，本身能发生相应的化学或物理变化的聚合物。目前大多数多重刺激响应性聚合物主要是将不同的刺激响应性基团通过无规共聚、嵌段聚合或者是接枝聚合等方法合成，然而这些方法都具有一定的局限性。为了寻找一种更为简单、高收率、低成本的制备方法，本项目采用了一种具有可逆、稳定可控的亚胺动态共价键，将末端带有醛基的不同环境刺激响应性树枝化基元（温度敏感和光敏感等）与侧链带有氨基的高分子进行动态共价键自组装，可非常简单、快速地构筑多重刺激响应性超分子树枝化聚合物。本项目重点研究了温敏性树枝化基元和光敏基团的结构和比例、主链结构、醛基/氨基比例、浓度、温度、pH值、光等因素对聚合物刺激响应行为的影响；通过对比考察主链构象对刺激响应行为的影响，进而深入研究了多重刺激响应机理。研究结果表明：采用亚胺动态共价键构筑多重刺激响应性聚合物的方法是可行，该方法具有高效、简易、操作方便、成本低、合成条件温和、相转变温度可控调控等优点；制备的聚合物表现出很好的温度、光、pH值、盐等多重刺激响应行为。该构筑方法为多重响应性聚合物的合成提供了新思路，丰富了多重刺激响应性聚合物的理论研究，也加深了多重响应性聚合物在工业应用方面的理论基础。