基于原子转移自由基聚合的光响应型木质纤维构建及作用机制

引入光响应基团作为组装基元制备智能高分子材料在传感器、分子电路、数据储存等领域具有巨大的潜在应用价值。然而此类材料多由塑化剂、聚乙烯塑料制备，存在生产和投资成本高，对环境有影响等缺陷。基于此，本论文以光控转换功能为导向，利用可再生的木质纤维为主体，通过分子设计在木质纤维素基团上组装具有光刺激响应的光致变色基团-丙烯酸螺吡喃，提出从功能化组装到光控变换的学术思路。课题通过对光致变色丙烯酸螺吡喃的设计制备、纯化表征，螺吡喃单元-木质纤维大分子组装体系的构建、原子转移自由基聚合反应的调控、产物结构的鉴定及定量分析等研究，明确光响应木质纤维组装体的形成规律和组装机理，揭示光响应木质纤维组装体的构建方法、组装规律和光控转换功能之间的内在联系。本项目的完成对木质纤维表面光响应特性组装具有重要理论价值，为天然高分子的多功能化构建及其应用提供科学依据。

Fabrications of smart materials through introducing light stimuli-responsive group into substrate have significant potential value in the field of sensors, molecular circuits and data storage. But the defects of these materials are their high cost and environmentally unfriendly features. This project, therefore, mainly aimed at light-stimuli responsive fiber. Wood fiber was chosen as the renewing backbone material, and was modified with photoresponsive group - spiropyran ether methacrylate (SPMA) at the surface of lignocellulose by molecular designation and assembly. This project will be carried out through designation, purification and structural characterization of SPMA, designation of wood fiber macromolecular assembly system with SPMA, regulation of atom transfer radical polymerization (ATRP) reaction, structure identification of the related products and quantitative analysis. Accordingly, a corresponding reaction mechanism and the assembly mechanism of light-stimuli responsive wood fiber macromolecular were determined. The links among construction method, assembly rule and light controlled transition functional properties of photosensitivity of light-stimuli responsive wood fiber were further explored. This research will provide theoretical values for definition of the mechanism of assembling light-stimuli responsive wood fiber. In addition, it will provide a scientific basis for multifunctionalized assembly of the natural polymer.