Facile syntheses of cylindrical molecular brushes by a sequential RAFT and ROMP "grafting-through" methodology.
Facile syntheses of cylindrical molecular brushes by a sequential RAFT and ROMP "grafting-through" methodology.
复制标题
DOI：
10.1002/pola.23626
复制
发表时间：
2009-10-15
影响因子：
--
通讯作者：
Wooley, Karen L.
中科院分区：
文献类型：
--
作者：
Li, Zhou;Zhang, Ke;Ma, Jun;Cheng, Chong;Wooley, Karen L.
关键词：
重要的兴趣是开发合成方法来制备含有功能的复杂大分子结构，允许刺激响应特性和进一步的化学修饰。1-6圆柱形分子刷是由许多侧链聚合物沿主链沿着密集分布而成的，通过选择合适的单体和调节主链和侧链的长度，可以精确控制其化学组成、尺寸和形貌，因而受到人们的广泛关注。7-9为了制备这样的结构，通常使用三种合成策略：“接枝到”8，9（通过偶联反应将侧链接枝到预先建立的多官能主链上），“接枝自”10-13（从多官能化引发主链生长侧链）和“接枝通过”14-18（通过其端基聚合先前合成的侧链）。以前，我们的实验室已经证明了三种主要的活性自由基聚合（氮氧介导的自由基聚合（NMRP）、原子转移自由基聚合（ATRP）和可逆加成-断裂链转移（RAFT）聚合）与开环易位聚合（ROMP）在“接枝自”方法中的相容性。12，19，20我们的兴趣最近集中在“接枝通过”方法上，因为它提供了对接枝密度、主链长度和侧链长度各自独立的特殊控制。虽然“接枝通过”方法在复杂大分子体系的构建中提供了多功能性，但在高分子量或空间体积大的大分子单体的聚合过程中可能会遇到空间位阻。为了克服这个问题，经常使用开环易位聚合，其通过从环状单体结构释放焓来驱动，并提供具有相对松散的接枝密度的聚合物主链。例如，已经报道了使用ROMP从聚苯乙烯封端的聚（环氧乙烷）、16聚苯乙烯、15聚磷腈、14聚（ε-己内酯）、18和聚丙交酯、17主要由阴离子聚合或开环聚合合成的大分子单体合成分子刷。NMRP、ATRP和RAFT是受控自由基聚合技术，其允许从乙烯基单体制备明确定义的聚合物，所述乙烯基单体可转化成基于ROMP的大分子单体。Grubbs最近报道了ATRP，点击化学和ROMP的优雅组合，以产生窄-
Of significant interest is the development of synthetic methodologies to prepare complex macromolecular structures that contain functionalities, allowing for stimuli-responsive characteristics and further chemical modifications. 1–6 The cylindrical molecular brush, which is composed of many side chain polymers distributed densely along a backbone, has attracted much attention because its chemical composition, size, and morphology can be controlled precisely by choosing appropriate monomers and tuning the lengths of the backbone and side chains. 7–9 To prepare such structures, three synthetic strategies are often used:‘‘grafting onto’’8, 9 (grafting side chains onto a pre-established multifunctional backbone by coupling reactions),‘‘grafting from’’10–13 (growth of side chains from a multifunctionalized initiating backbone), and ‘‘grafting through’’14–18 (polymerization of previously synthesized side chains through their terminal groups). Previously, our laboratory has demonstrated the compatibility of the three primary living radical polymerizations (nitroxide mediated radical polymerization (NMRP), atom transfer radical polymerization (ATRP), and reversible addition-fragmentation chain transfer (RAFT) polymerization) together with ring-opening metathesis polymerization (ROMP) in the ‘‘grafting from’’method. 12, 19, 20 Our interest has focused recently on the ‘‘grafting through’’method, because it provides exceptional control over the grafting density, the length of the backbone, and the length of the side chains, each independently. Although the ‘‘grafting through’’approach offers versatility in the construction of complex macromolecular systems, it is likely to encounter steric hindrance during the polymerization of high molecular weight or sterically-bulky macromonomers. 21, 22 To overcome this issue, ROMP has often been used, which is driven by the release of enthalpy from cyclic monomer structures and affords a polymer backbone with a relatively loose grafting density. For example, the syntheses of molecular brushes have been reported using ROMP from norbornene-terminated poly (ethylene oxide), 16 polystyrene, 15 polyphosphazene, 14 poly (e-caprolactone), 18 and polylactide, 17 macromonomers synthesized mainly from anionic polymerization or ring opening polymerization. NMRP, ATRP, and RAFT are controlled radical polymerization techniques that allow for the preparation of well-defined polymers from vinylic monomers, which can be converted into ROMP-based macromonomers. Grubbs recently reported an elegant combination of ATRP, click chemistry, and ROMP to produce narrowly-
登录
查看更多内容
影响因子：
5.5
作者：
Heroguez, V;Breunig, S;Fontanille, M
通讯作者：
Fontanille, M
影响因子：
5.5
作者：
Xia, Yan;Kornfield, Julia A.;Grubbs, Robert H.
通讯作者：
Grubbs, Robert H.
影响因子：
--
作者：
BREUNIG, S;HEROGUEZ, V;FONTANILLE, M
通讯作者：
FONTANILLE, M
影响因子：
3.9
作者：
PRADIP;MALTESH, C;GUNDIAH, S
通讯作者：
GUNDIAH, S
影响因子：
--
作者：
Wiltshire, James T.;Qiao, Greg G.
通讯作者：
Qiao, Greg G.