This paper elaborated the preparation of spiro-shaped multicyclic polymer with repeating heterocyclics. Block copolymer PEO-PS-Br was prepared by atom transfer radical polymerization (ATRP) of styrene (St) with a poly(ethylene oxide) telechelic macroinitiator PEO-Cou-Br, in which both ends of PEO chain were capped by coumarin groups in advance. After azidation of terminal bromine, bimolecular cyclization was conducted with a diyne as difunctional linker to provide heterocyclic polymer with coumarin groups at the boundaries between PEO and PS blocks. The heterocyclic polymer was exposed to UV irradiation at 365 nm to afford spiro-shaped multicyclic polymer via dimerization of coumarin. GPC, ¹H NMR and FT-IR were used to characterize obtained products. Photocleavage of multicyclic polymer under irradiation of 254 nm was also investigated, and GPC trace suggests the successful cleavage from spiro-shaped structure to monocycles.

本文阐述了具有重复杂环的螺形多环聚合物的制备方法。嵌段共聚物 PEO-PS-Br 是通过苯乙烯 (St) 与聚环氧乙烷遥爪大引发剂 PEO-Cou-Br 的原子转移自由基聚合 (ATRP) 制备的，其中 PEO 链的两端均被香豆素基团封端。进步。在末端溴叠氮后，用二炔作为双官能连接剂进行双分子环化，以在PEO和PS嵌段之间的边界处提供具有香豆素基团的杂环聚合物。将杂环聚合物暴露于 365 nm 的紫外线照射下，通过香豆素的二聚化得到螺形多环聚合物。GPC, ¹H NMR和FT-IR用于表征所得产物。还研究了多环聚合物在 254 nm 照射下的光裂解，GPC 迹线表明成功地从螺形结构裂解为单环。