PHEA-g-PDMAEA well-defined graft copolymers: SET-LRP synthesis, self-catalyzed hydrolysis, and quaternization
PHEA-g-PDMAEA well-defined graft copolymers: SET-LRP synthesis, self-catalyzed hydrolysis, and quaternization
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DOI：
10.1039/c6py01637e
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发表时间：
2016-11
影响因子：
4.6
通讯作者：
Fang-gang Sun;Chun Feng;Haoyu Liu;Xiaoyu Huang
中科院分区：
文献类型：
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作者：
Fang-gang Sun;Chun Feng;Haoyu Liu;Xiaoyu Huang
采用可逆加成-断裂链转移（RAFT）聚合和单电子转移活性自由基聚合（SET-LRP）方法，通过接枝-自来策略合成了两种结构明确的接枝共聚物，分别由亲水性的聚（丙烯酸2-羟乙酯）（PHEA）主链和聚（丙烯酸2-二甲氨基乙酯）（PDMAEA）侧链组成。首先将包含-COCH（CH 3）Cl SET-LRP引发基团的三官能2-（（2-氯丙酰氧基）甲基）丙烯酸2-羟乙酯单体进行RAFT均聚，得到在每个重复单元中带有含Cl SET-LRP引发基团的PHEA基均聚物，其具有窄的分子量分布（Mw/Mn = 1.08）。该均聚物直接引发丙烯酸2-二甲氨基乙酯的SET-LRP，得到目标明确的聚（丙烯酸2-羟乙酯）-接枝-聚（丙烯酸2-二甲氨基乙酯）（PHEA-g-PDMAEA）接枝共聚物（Mw/Mn ≤ 1.17），在主链的每个重复单元中具有羟基，而没有聚合物官能度转化。所得的水溶性接枝共聚物在中性和碱性水溶液中均能在室温下自水解。此外，PHEA-g-PDMAEA可以在水介质中季铵化，以便在有机相中聚集成反胶束。
Two well-defined graft copolymers consisting of a hydrophilic poly(2-hydroxyethyl acrylate) (PHEA) backbone and poly(2-dimethylamino ethylacrylate) (PDMAEA) side chains were synthesized by sequential reversible addition–fragmentation chain transfer (RAFT) polymerization and single-electron-transfer living radical polymerization (SET-LRP) via the grafting-from strategy. A trifunctional 2-hydroxyethyl 2-((2-chloropropanoyloxy)methyl)acrylate monomer comprising a –COCH(CH3)Cl SET-LRP initiating group was first RAFT homopolymerized to give a PHEA-based homopolymer bearing a Cl-containing SET-LRP initiating group in every repeated unit with a narrow molecular weight distribution (Mw/Mn = 1.08). This homopolymer directly initiated SET-LRP of 2-(dimethylamino)ethyl acrylate for affording the target well-defined poly(2-hydroxyethyl acrylate)-graft-poly(2-dimethylamino ethylacrylate) (PHEA-g-PDMAEA) graft copolymers (Mw/Mn ≤ 1.17) with hydroxyl in every repeated unit of the backbone without polymeric functionality transformation. The obtained water-soluble graft copolymers could self-hydrolyze in neutral and basic aqueous solutions at ambient temperature without external stimuli. Furthermore, PHEA-g-PDMAEA can be quaternized in aqueous media so as to aggregate into reversed micelles in the organic phase.