基于纳米受限环状低聚酯边聚合边结晶的结构演变与取向调控研究

Polymer crystallization under nanoconfinement is an important basic subject in polymer physics. In this project, using nanoporous anodized aluminum oxide templates and taking cyclic butylene terephthalate oligomer (CBT) as an example, we investigate the crystallization during polymerization of aromatic cyclic oligoesters based on the nanoconfined ring-opening polymerization of CBT. The structure formation and evolution of resulting poly(butylene terephthalate) (denoted by PCBT) and the effects of temperature, pore size, surface property on the crystallization and orientation of PCBT are explored to uncover the interplay of chain propagation-nucleation-crystal growth-structure evolution during CBT ring-opening polymerization, and then to reveal the microscopic construction mechanism of hierarchical structures from cyclic monomers to polymer chains and further to crystal. The launching of this project not only can develop the nature of the crystallization during polymerization of aromatic cyclic oligoesters under nanoconfinement and achieve the effective manipulation of crystallization and orientation of formed aromatic polyesters, but also provide both experimental and technological basics for potential applications of aromatic cyclic oligoesters in nanomaterial science.

纳米受限高分子结晶是高分子物理的重要基础课题。本项目利用多孔阳极氧化铝纳米模板，以环状对苯二甲酸丁二酯低聚物(CBT)为示例对象，基于受限开环聚合的方法开展纳米受限芳香环状低聚酯边聚合边结晶行为的研究。重点研究CBT受限聚合中产物聚对苯二甲酸丁二酯(PCBT)晶体结构的形成与演变和考察反应温度、孔洞尺寸、表面性质等条件对PCBT结晶取向的调控作用，以明确纳米CBT受限边聚合边结晶过程中链增长-结晶成核-晶体生长-结构演变的相互作用关系和揭示从大环单体到聚合物分子链再到晶体的多级结构的微观构筑机理。项目的开展不仅能发展对纳米受限芳香环状低聚酯边聚合边结晶机理的本质认识和实现对产物芳香聚酯结晶取向的有效调控，还将为芳香环状低聚酯在纳米材料领域的潜在应用奠定实验和理论基础。

本项目选用阳极氧化铝（AAO）纳米多孔模板，以环状对苯二甲酸丁二酯二聚体（CBT）为研究对象，基于纳米受限聚合的方法，成功制备了尺寸可控的聚对苯二甲酸丁二酯（记为PCBT）纳米棒，研究了AAO纳米受限CBT聚合过程中的边聚合边结晶行为，探索了聚合温度、孔径大小对产物PCBT纳米棒物理性质和晶体结构的影响规律，发展了纳米受限边聚合边结晶过程中从大环单体直接到聚合物微晶的活性片晶增长的微观结晶机理，基于聚合温度、聚合程序和孔径尺寸讨论了调控PCBT纳米棒中晶体取向的有效方法，为拓展芳香环状低聚脂在纳米材料领域的应用打下了理论和实验基础。