基于主/侧链结构设计的偶氮苯聚醚制备及其光致变色性能研究

Preparation and Study on Photochromic Performance of Azobenzene Polyether Based on Backbone/Branched Chain Structure Designing

偶氮苯结构的有序化引入可赋予聚合物快速可逆光响应行为,但要进一步提高偶氮苯类光致变色聚合物材料的变色均匀程度与可控性,还需进一步设计偶氮苯基聚合物链结构及功能结构的排列方式。本文通过烯丙基缩水甘油醚(allyl glycidyl ether,AGE)开环聚合制备具有不饱和侧基结构的聚烯丙基缩水甘油醚(poly(allyl glycidyl ether),PAGE)。利用Thiol-ene点击化学和酯化反应将对二羧基偶氮苯接枝到聚醚侧链上,合成具有光敏特性的支化聚醚结构。探究点击化学反应条件对接枝率的影响,并根据反应条件与接枝率之间的关系优化结构设计,获得具有快速光致构象转变的偶氮苯(azobenzene,Azo)接枝聚醚(Azo-g-polyester)。具有偶氮苯侧链的PAGE材料(PAGE-OH-Azo)具有良好的光响应性。在连续紫外光和蓝光照射下,液相PAGE-OHAzo体系展示出快速可逆的颜色变化,且这一过程循环稳定性较好。本工作通过设计并优化主链与侧基结构获得变色性能稳定且优异的聚醚材料,为拓宽含偶氮苯结构的聚醚在光活性聚合物领域的应用提供了实践基础。

The introduction and orderly alignment of azobenzene moieties can bring the polymer rapid and reversible photoresponsive behavior.To improve the uniformity and controllability of azophenyl photochromic polymer materials,it is necessary to further design the topological structures of the main chain and functional branches.In this work,poly(allyl glycidyl ether)(PAGE)with unsaturated side groups was prepared by ring-opening polymerization of allyl glycidyl ether(AGE).The unsaturated side structures were hydroxylated via thiol-ene click chemistry,followed by a modification of photosensitive p-dicarboxylic azobenzene moieties.The influence of click chemical reaction conditions on the grafting ratio was investigated,and the design and optimization of the side chain structures had been carried out according to the relationship between the reaction conditions and grafting ratio.Ultimately,the azobenzene grafted polyether(PAGE-OH-Azo)with rapid conformational transition behavior under ultra violate had been obtained,which possesses good photo-responsiveness.Under continuous irradiation of ultraviolet and blue light,the PAGE-OH-Azo shows rapid reversible and cyclic-stable color change in liquid phase.By designing and optimizing the main chain and side group structures,polyethers with reliable and controllable color-changing properties were obtained,providing a practical basis on expanding the application of azobenzene modified polyether in the field of photoactive polymers.