Synthesis of Amphiphilic Heteroeight-Shaped Polymer Cyclic-[Poly(ethylene oxide)-b-polystyrene]2 via "Click" Chemistry
Synthesis of Amphiphilic Heteroeight-Shaped Polymer Cyclic-[Poly(ethylene oxide)-b-polystyrene]2 via "Click" Chemistry
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DOI：
10.1021/ma300487x
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发表时间：
2012-05-08
期刊：
影响因子：
5.5
通讯作者：
Huang, Junlian
中科院分区：
文献类型：
--
作者：
Fan, Xiaoshan;Huang, Bing;Huang, Junlian
将阴离子开环聚合（ROP）和原子转移自由基聚合（ATRP）机理与“点击”化学反应相结合，合成了一种由亲水性聚氧化乙烯（PEO）和疏水性聚苯乙烯（PS）嵌段组成的两亲性杂八字形环状聚合物[c-（PEO-b-PS）]（2）。按照“核优先”的策略，通过环氧乙烷单体的开环聚合、苯乙烯单体的原子转移自由基聚合和官能团的修饰，得到了A（2）B（2）星形前体（PEO-炔）（2）-（PS-N-3）（2）。在高稀释度条件下，（PEO-炔）（2）-（PS-N-3）（2）通过“点击”化学发生分子内环化反应，生成两亲性杂八型聚合物[c-（PEO-b-PS）]（2）。通过GPC、MALDI-TOF MS、H-1 NMR和FT-IR等手段对目标共聚物和中间体进行了表征。通过透射电子显微镜（TEM）和动态光散射（DLS）研究并比较了[c-（PEO-b-PS）]（2）及其前体（PEO-alkyne）（2）-（PS-N-3）（2）的自组装行为。在这两种情况下，观察到的球形胶束，但是，形成的胶束的大小增加，从一个星形的环状拓扑结构。
An amphiphilic heteroeight-shaped polymer cyclic-[poly(ethylene oxide)-b-polystyrene](2) ([c-(PEO-b-PS)](2)) composed of hydrophilic PEO and hydrophobic PS blocks was synthesized by combination of "click" chemistry with anionic ring-opening polymerization (ROP) and atom transfer radical polymerization (ATRP) mechanisms. According to "core-first" strategy, the A(2)B(2) star-shaped precursor (PEO-alkyne)(2)-(PS-N-3)(2) was obtained by successive ROP of EO monomer, ATRP of St monomer, and modification of functional groups. Under high dilution condition, the intramolecular cyclization of (PEO-alkyne)(2)-(PS-N-3)(2) by "click" chemistry produced the amphiphilic heteroeight-shaped polymer [c-(PEO-b-PS)](2). The target copolymers and intermediates were well characterized by GPC, MALDI-TOF MS, H-1 NMR, and FT-IR The self-assembly behavior of [c-(PEO-b-PS)](2) and its precursor of (PEO-alkyne)(2)-(PS-N-3)(2) were investigated and compared by transmission electron microscopy (TEM) and dynamic light scattering (DLS). In both cases, the spherical micelles were observed, however, the size of formed micelles increased from a star-shaped to a cyclic topology.