作者：Chengxin Shang, Jianxiong Xu, Xiaohui Wang, Xu Zhang, Wangqing Zhang, and Tianyong Zhang
关键字：RAFT polymerization
论文来源：期刊
具体来源：Polymer
发表时间：2012年

A new method to achieve well-controlled surfactant-free aqueous RAFT polymerization of styrene initiated by K₂S₂O₈ in the presence of CaCO₃ particles was proposed. It was found that the hydrophobic monomer of styrene was adsorbed on the surface of CaCO₃ particles and well-controlled surfactant-free aqueous RAFT polymerization mediated with the RAFT agent of S,S′-bis(α,α′-dimethyl-α″-acetic acid) trithiocarbonate (BDMAT) was achieved. The weight ratio of the feeding CaCO₃ to the styrene monomer on the aqueous RAFT polymerization was investigated, and it was found that high CaCO₃/styrene weight ratio led to fast aqueous RAFT polymerization. The aqueous RAFT polymerization kinetics was checked, and the fast RAFT polymerization rate at low molar ratio of styrene/BDMAT/K₂S₂O₈, the linear ln([M]_o/[M])–time plot, the linear increase in the number–average molecular weight with the monomer conversion, and the relatively low PDI values (1.1∼1.3) were demonstrated. The surfactant-free aqueous RAFT polymerization was compared with the general emulsion RAFT polymerization in the presence of the sodium dodecyl sulfate (SDS) surfactant. It was found that the surfactant-free aqueous RAFT polymerization seemed more valid than the emulsion RAFT polymerization. The proposed method is believed to be a new strategy to achieve well-controlled surfactant-free aqueous RAFT polymerization.

www.sciencedirect.com/science/article/pii/S0032386112010488