Controlled radical polymerization of N-vinylpyrrolidone by reversible addition-fragmentation chain transfer process
Controlled radical polymerization of N-vinylpyrrolidone by reversible addition-fragmentation chain transfer process
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DOI：
10.1002/masy.200551102
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发表时间：
2005-01-01
影响因子：
--
通讯作者：
Gnanou, Y
中科院分区：
文献类型：
--
作者：
Devasia, R;Bindu, RL;Gnanou, Y
以二乙基丙二酸二苯基二硫代氨基甲酸酯(DPCM)为可逆链转移剂，在少量常规自由基引发剂(AIBN)存在下，采用RAFT法聚合了聚N-乙烯基吡咯烷酮(PNVP)。用这种方法合成的聚合物的摩尔质量随着转化率和时间的增加而增加。H-1核磁共振谱证实了聚合物链中端基的存在。用H-1核磁共振波谱和静态光散射(SLS)计算的摩尔质量与理论摩尔质量吻合较好。RAFT化合物在聚合的初始阶段被完全消耗。通过单体如苯乙烯或丙烯酸丁酯(n-BA)的顺序添加生成两嵌段共聚物，进一步证实了这些聚合物的受控性质。PNVP作为大分子RAFT试剂有效参与，两嵌段之间有效地发生交叉反应。使用PNVP作为宏观转移剂的两嵌段共聚物的成功合成进一步证实了这种合成过程的“受控”性质。
Poly(N-vinylpyrrolidone) (PNVP) was polymerized by RAFT process using diphenyldithiocarbamate of diethylmalonate (DPCM) as the reversible chain transfer agent in the presence of a small percentage of a conventional radical initiator (AIBN). The molar mass of the polymers synthesized by this method was found to increase with conversion and time. The presence of end group in the polymer chain could be confirmed by H-1 NMR spectra. The molar masses calculated using H-1 NMR spectroscopy and static light scattering (SLS) showed good agreement with the theoretical molar masses. The RAFT compound was fully consumed during the initial stages of the polymerization itself. The controlled nature of these polymers was further confirmed by generating diblock copolymers by sequential addition of monomers such as styrene or n-butyl acrylate (n-BA). PNVP efficiently participated as a macro-RAFT reagent, and cross-over reaction between the two blocks efficiently occurred. The successful diblock copolymer synthesis using PNVP as macro-transfer reagent further confirms the "controlled" nature of such synthetic procedure.