论文摘要
Mixtures of a weak protonic acid and a trace amount of superstrong protonic acid were used for the simple control of the cationic polymerization of vinyl ethers via a degenerative chain-transfer mechanism, in which the former acid works as a precursor of the chain transfer agent（CTA） or the dormant species and the latter works as a source of the cationic propagating species. The addition of mixtures of phosphoric acid dibutyl ester（（n-BuO）2PO2 H） or 1-octanethiol(n-C8H17 SH) and a trace amount of trifluoromethanesulfonic acid（TfOH） to a solution of isobutyl vinyl ether（IBVE） at-78 °C resulted in polymers with controlled molecular weights, which were basically determined by the feed ratio of IBVE to the weak protonic acid, and narrow molecular weight distributions（Mw/Mn ≈ 1.1）. These results were almost the same as those obtained using their prepared adducts of IBVE as CTAs in the presence of a trace amount of TfOH under similar conditions. Methanesulfonic acid（CH3SO3 H）, whose adduct of IBVE has not been isolated due to instability, was similarly used in conjunction with trace TfOH to result in controlled molecular weights but slightly broader MWDs（Mw/Mn = 1.2–1.8）. These results indicate that the sulfoxonium ion is also an effective intermediate in the cationic DT polymerization in addition to the phosphonium and sulfonium intermediates derived from（n-BuO）2PO2 H and n-C8H17 SH, respectively. The simple living cationic polymerization was thus achieved by using a combination of a weak protonic acid and a trace amount of TfOH, which are both easily available, low cost, free from metal, and easy to handle, without need for preparation of the initiator.
论文目录
文章来源
类型: 期刊论文
作者: Mineto Uchiyama,Masataka Sakaguchi,Kotaro Satoh,Masami Kamigaito
来源: Chinese Journal of Polymer Science 2019年09期
年度: 2019
分类: 工程科技Ⅰ辑
专业: 化学
单位: Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Furo-cho, Chikusa-ku, Nagoya University
基金: supported in part by a JSPS KAKENHI Grant-inAid for Early-Career Scientists (No. JP18K14274) for M.U
分类号: O631.5
页码: 851-857
总页数: 7
文件大小: 784K
下载量: 13