光调控聚合中RAFT试剂的理性设计研究

传统自由基聚合方法难以调控聚合物分子量及其分布情况，限制了合成聚合物材料的高性能化。PET-RAFT聚合（光诱导电子转移-可逆加成断裂链转移聚合）通过可逆的链终止和RAFT链转移机理实现可控聚合，且在光调控下具有耐氧、快速光响应和时序/空间控制的特点。然而，目前PET-RAFT聚合采用的RAFT链转移剂（RAFT试剂）基本上均从传统RAFT试剂筛选而来，未针对光调控聚合优化，性能缺陷或局限较多。本项目结合理论计算和实验手段，在深入探究PET-RAFT聚合链引发和链转移机理的基础上，进一步综合利用波函数分析方法构建了RAFT试剂和PET-RAFT聚合之间的“结构-性质-表现”关系，从而可指导RAFT试剂修饰改性。基于光调控聚合对光源可穿透性的需求，申请人拟在“结构-性质-表现”关系的指导下对RAFT试剂进行修饰改性，使其适用于近红外光PET-RAFT聚合。

Conventional radical polymerization is the most used technique in polymer production. However, it lacks control over molecular weight distribution of polymers, which limits further enhancement of mechanical properties of polymers. By implementing reversible deactivation, reversible addition-fragmentation chain transfer (RAFT) and photoinduced electron transfer (PET) mechanisms, PET-RAFT polymerization is endowed with oxygen tolerance, rapid light-response and precise temporal/spatial control. However, at this stage, the only RAFT agents implemented in PET-RAFT polymerization stem from traditional RAFT polymerization systems and are thus not fully optimized for photo-controlled systems. This project aims to perform mechanistic studies on the photoinitiation and the RAFT chain transfer processes by combined use of computational and experimental protocols. On top of that, this project will establish and verify “structure-property-performance” relationships for RAFT agents in PET-RAFT polymerization, in order to enable rational design of RAFT agents. Finally, to meet the need for promoting light penetration in photo-controlled polymerization, this project will tailor properties of the RAFT agent by rational ligand modification and thereby receive a new RAFT agent capable of controlling rapid near-infrared light PET-RAFT polymerization.