以糠醛等可再生资源为原料制备可自修复聚合物的研究

Exploration and application of renewable resources draw greater attention in recent years due to crisis of fossil resources. Furfural and its derivatives are cheap and can be prepared from sufficient renewable wastes of agriculture and forestry. In this project, we will synthesize intrinsically self-healing polymers via synthetic methods of polymers (click reaction, coupling reaction, multi-component reaction, living radical polymerization, etc.). Firstly, the corresponding intermediates are synthesized, followed by preparation of relatively simple polymers, and self-healing performance will be researched under a certain condition such as light, heating, redox, acid-base. Secondly, multi-functional-group polymers will be designed, which are expected to have self-healing property under different conditions such as light and heating. Furthermore, self-healing efficiency may be promoted for these multi-functional-group polymers. When the polymers are intendedly scratched or cut, their self-healing behavior is observed and researched by SEM and other methods. Modification of the polymers such as structure, functional groups, rigidity, molecular weight will be conducted if their self-healing properties are not ideal. Strength of the polymers will be improved by modification of structures, hybridization, and blending. Relationship of structure and self-healing properties will be studied to find the corresponding principles, which will provide useful information on synthesis of self-healing polymer materials.

由于化石资源危机，利用基于可再生资源的分子设计合成聚合物，日益引起人们的重视。糠醛及其衍生物可从丰富的农林废料制备。本项目拟以糠醛及其衍生物等为原料，利用有机合成与高分子合成的手段(点击反应、偶联反应、多组分反应、活性自由基合等)，设计合成本征型自修复聚合物。首先制备结构相对简单的聚合物，研究其在光照、加热、氧化-还原、酸碱等单一条件下的自修复性能。然后制备多官能团的聚合物，使其在光照、加热等不同条件下都能进行自修复，提高自修复效率。通过人为破坏聚合物材料，然后利用 SEM 等手段观察聚合物的自修复行为和修复程度，若自修复性能不理想，则调整聚合物的结构、官能团种类及数量、刚性大小、分子量等。利用结构改进、掺杂、共混等手段，提高自修复聚合物的机械强度。初步研究聚合物的结构与自修复性能的关系，找出相应的规律，为以后设计自修复聚合物提供理论依据。

糠醛及其衍生物可从价廉丰富的农林废料中制备，对这些可再生资源的充分利用，对于缓解甚至解决化石资源危机具有重要的价值。高分子材料在使用中可能会产生微裂纹，而这些损伤一方面较难检测到，另一方面即使发现但在特殊使用环境中也不易修补 (例如地下管道、高层建筑设施、航海设备等)，如果任其发展可能会影响材料的使用性能和使用寿命，甚至引发严重的事故。本项目以糠醛、丁香酚、香草醛等可再生资源为原料，通过分子设计、聚合反应来制备本征型可自修复聚合物，使这些聚合物可在特定的外界条件（如光照、加热）下，进行多次自修复。分别以糠醛和5-羟甲基糠醛(HMF)为原料，利用Baylis-Hillman 反应合成相应的含呋喃环的单体，然后进行自由基聚合或与二异氰酸酯反应，得到含有呋喃侧基的线型聚合物，最后与双马来酰亚胺进行 Diels-Alder 环加成反应，得到加热条件下可自修复的交联聚合物。以丁香酚为原料，先合成含有两个端烯的中间体，然后利用巯基-烯、巯基氧化反应，制备含有二硫键的可自修复交联聚合物。以丁香酚为原料，先合成端基溴代物，然后与糠胺反应，得到含有双端烯与呋喃环的小分子中间体，然后然后利用巯基-烯、巯基氧化反应，制备含有二硫键的聚合物，最后与双马来酰亚胺进行 Diels-Alder 环加成反应，得到在光照或加热条件下都能进行自修复的聚合物。通过本课题的研究，扩大了糠醛等可再生资源的应用范围，为自修复聚合物的设计提供了新的思路与方法。