Expanding the Scope of the Photoinduced Living Radical Polymerization of Acrylates in the Presence of CuBr2 and Me6-Tren
Expanding the Scope of the Photoinduced Living Radical Polymerization of Acrylates in the Presence of CuBr2 and Me6-Tren
复制标题
DOI：
10.1021/ma500787d
复制
发表时间：
2014-06-24
期刊：
影响因子：
5.5
通讯作者：
Haddleton, David M.
中科院分区：
文献类型：
--
作者：
Anastasaki, Athina;Nikolaou, Vasiliki;Haddleton, David M.
在低浓度CuBr2存在下，在脂肪族叔胺配体(Me-6-Tren)的存在下，通过紫外光照射(最大吸收波长接近360 nm)，实现了丙烯酸酯的光诱导活性自由基聚合，得到了几乎完全保持端基保真度的聚丙烯酸酯。考察了溶剂性质对聚合速率的影响，以扩大该体系的适用范围和确定其局限性。随后，筛选出了一系列含有疏水和亲水取代基的丙烯酸酯单体，包括丙烯酸十二酯、丙烯酸十八酯和二甘醇乙醚丙烯酸酯，所有这些单体在很高的转化率下都表现出低分散性(D约为1.1)。功能单体，包括丙烯酸缩水甘油酯和丙烯酸酯醇缩醛，也被发现对光甲基化反应有耐受性。最后，将丙烯酸酯缩醇缩醛与丙烯酸甲酯进行共聚，得到了一种两亲性两嵌段共聚物。用动态光散射(DLS)和透射电子显微镜(TEM)研究了该嵌段共聚物在水介质中自组装成聚合物胶束的情况。
Photoinduced living radical polymerization of acrylates is achieved upon UV irradiation (lambda(max) approximate to 360 nm) in the presence of an aliphatic tertiary amine ligand (Me-6-Tren) in the presence of low concentrations of CuBr2, yielding poly(acrylates) with near perfect retention of end group fidelity. The effect of the nature of the solvent on the rate of polymerization was investigated in order to expand the scope and identify the limitations of the system. Subsequently, a range of acrylic monomers containing hydrophobic and hydrophilic substituents have been screened, including lauryl acrylate, octadecyl acrylate and diethylene glycol ethyl ether acrylate, all of which present low dispersities (D approximate to 1.1) at very high conversions. Functional monomers, including glycidyl acrylate and solketal acrylate, were also found to be tolerant to the photomediated reaction. Finally, solketal acrylate was copolymerized with methyl acrylate which, following deprotection of the pendant ketal group, furnished an amphiphilic diblock copolymer. Self-assembly of this block copolymer into polymer micelles in aqueous media was exemplified by dynamic light scattering (DLS) and transmission electron microscopy (TEM).