Photoinduced electron transfer-reversible addition–fragmentation chain transfer (PET-RAFT) polymerization of vinyl acetate (VAc) and acrylic acid (AA) was successfully realized in methanol at room temperature under blue LED (420 nm, 6 mW/cm²) irradiation with xanthate as RAFT agent and fac-[Ir(ppy)₃] as the photocatalyst. The well-defined copolymers of poly(VAc-co-AA) with controlled molecular weights (M_n,GPC) and polydispersity index (PDI) were successfully obtained. The polymerization revealed the behaviors of controlled/living polymerization, which was verified by the observed linear relationship of ln([M]₀/[M]_t) with respect to irradiation time and that of the experimental molecular weights (M_n,GPC) with respect to monomer conversion. GPC curves showed a single peak and shifted to high molecular weights with increasing the irradiation time. The reactivity ratios of VAc and AA were 0.043 and 1.181, respectively in this system. The effect of the amount of fac-[Ir(ppy)₃] on PET-RAFT polymerization was investigated. The monomer conversion increased with increasing the amount of fac-[Ir(ppy)₃] and the PDI decreased with the increase in the amount of fac-[Ir(ppy)₃]. The temporal controllable PET-RAFT polymerization of vinyl acetate (VAc) and acrylic acid (AA) was achieved. The structure of synthesized poly(VAc-co-AA) was characterized by nuclear magnetic resonance spectroscopy (¹H NMR) and gel permeation chromatography (GPC), respectively. The extended experiments of poly(VAc-co-AA) with fresh AA was conducted under the irradiation of blue LED, and the results demonstrated that this extension polymerization displayed controlled polymerization behavior. The mechanism was explained in this study.

室温下在蓝色LED（420 nm，6 mW / cm ²）照射下，在甲醇中成功实现了乙酸乙烯酯（VAc）和丙烯酸（AA）的光诱导电子转移可逆加成-断裂链转移（PET-RAFT）聚合。以黄药为RAFT剂，以fac- [Ir（ppy）₃ ]为光催化剂。成功获得了分子量（M _n，GPC）和多分散指数（PDI）可控的聚（VAc- co -AA）共聚物。聚合反应揭示了受控/活性聚合反应的行为，这已通过观察到的ln（[ M ] ₀ / [ M ]关于辐射时间的_t）和关于单体转化率的实验分子量（ M _n，GPC）。GPC曲线显示一个峰，并随着照射时间的增加而转移到高分子量。在该系统中，VAc和AA的反应率分别为0.043和1.181。研究了fac- [Ir（ppy） ₃ ]的量对PET-RAFT聚合的影响。单体转化率随fac- [Ir（ppy） ₃ ]的增加而增加，PDI随fac- [Ir（ppy） ₃的增加而减少。]。实现了醋酸乙烯酯（VAc）和丙烯酸（AA）的时间可控PET-RAFT聚合。分别通过核磁共振波谱（¹ H NMR）和凝胶渗透色谱法（GPC）对合成的聚（VAc- co -AA）的结构进行表征。在蓝色LED的照射下，对聚（VAc- co- AA）与新鲜AA进行了扩展实验，结果表明该扩展聚合反应表现出受控的聚合行为。在这项研究中解释了该机制。