State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou, 215123, P. R. China.
State Key Laboratory of Radiation Medicine and Protection, School of Radiation Medicine and Protection, Soochow University, Suzhou, 215123, P. R. China.
Macromol Rapid Commun. 2022 Apr;43(8):e2100920. doi: 10.1002/marc.202100920. Epub 2022 Feb 17.
A photocontrolled reversible addition-fragmentation chain transfer (RAFT) process is developed by initiating polymerization through a 1,3-diaminopropane-triethylborane (DAPTB)-diphenyl iodonium salt (Ph I ) complex (DAPTB/Ph I ) under ambient temperature and atmospheric conditions. Upon demand, this air-stable DAPTB/Ph I complex is photolyzed to liberate a reactive triethylborane that consumes atmospheric oxygen and generates ethyl radicals, which initiate and mediate RAFT polymerization. Controlled RAFT polymerization is thus achieved without any prior deoxygenation using a novel RAFT chain transfer agent, BP-FSBC, which contains both benzophenone and sulfonyl fluoride moieties. Furthermore, the kinetics of polymerization reveal that the reaction process is rapid, and well-defined polymers are produced by a 61% conversion of 2-hydroxyethyl acrylate (HEA) within 7 min and 77% conversion of N,N-dimethylacrylamide (DMA) within 10.5 min. The temporal and spatial control of this photopolymerization is also demonstrated by an "on/off" switch of UV irradiation and a painting-on-a-surface approach, respectively. In addition, active chain ends are demonstrated by preparing block copolymers by chain extension and click sulfur(VI)-fluoride exchange postreaction using RAFT-derived macrochain transfer agents.
在环境温度和大气条件下，通过 1,3-二氨基丙基三乙硼烷（DAPTB）-二苯基碘鎓盐（Ph I ）配合物（DAPTB/Ph I ）引发聚合，开发了一种光控可逆加成-断裂链转移（RAFT）过程。根据需要，这种空气稳定的 DAPTB/Ph I 配合物可光解为释放出活性三乙硼烷，消耗大气中的氧气并生成乙基自由基，引发并介导 RAFT 聚合。因此，无需事先脱氧，即可使用新型 RAFT 链转移剂 BP-FSBC 实现受控 RAFT 聚合，该链转移剂含有苯甲酮和砜基部分。此外，聚合动力学表明，该反应过程迅速，通过 2-羟乙基丙烯酰胺（HEA）的 61%转化率在 7 分钟内和 N,N-二甲基丙烯酰胺（DMA）的 77%转化率在 10.5 分钟内即可生产出具有良好定义的聚合物。通过紫外线照射的“开/关”开关和表面绘画方法，分别证明了这种光聚合的时间和空间控制。此外，通过使用 RAFT 衍生的大分子链转移剂进行链延伸和点击硫（VI）-氟化物交换后反应，制备了嵌段共聚物，证明了活性链末端的存在。
