Densely-grafted and double-grafted PEO brushes via ATRP. A route to soft elastomers
Densely-grafted and double-grafted PEO brushes via ATRP. A route to soft elastomers
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DOI：
10.1021/ma0345347
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发表时间：
2003-09-09
期刊：
影响因子：
5.5
通讯作者：
Matyjaszewski, K
中科院分区：
文献类型：
--
作者：
Neugebauer, D;Zhang, Y;Matyjaszewski, K
采用原子转移自由基聚合（ATRP）方法，在有机溶剂中合成了两种不同聚合度（DPPEO = 5和23）的含环氧乙烷（EO）链段的大分子单体，并分别用甲氧基和甲基丙烯酸酯（PEOMA）封端。除了通过大分子单体“接枝”直接制备致密接枝刷状共聚物之外，（MWav = 300 g/mol，DPPEO = 5）也用于使用定义明确的多官能大分子引发剂聚（甲基丙烯酸甲酯）的“接枝自”反应。（甲基丙烯酸2-（2-溴丙酰氧基）乙酯）（PBPEM，M-n，M-app = 82 × 10（3）g/Mol，M-w/M-n = 1.16，主链聚合度DPb = 428）。该程序允许制备具有各种侧链聚合度（DPsc = 12-43）的密集双接枝刷状共聚物。尝试制备DPsc > 50的双接枝刷或在“接枝自”反应中使用具有较长PEO链的大分子单体（MWav = 1100 g/mol，DPPEO = 23）导致形成交联凝胶。交联的单接枝和双接枝刷状共聚物都是具有软橡胶性质（G'类似于10（4）Pa）的一类新的弹性体材料的实例。
Two macromonomers containing ethylene oxide (EO) segments with different degrees of polymerization (DPPEO = 5 and 23), capped by a methoxy and a methacrylate group (PEOMA), were polymerized by atom transfer radical polymerization (ATRP) in organic solvents. In addition to the direct preparation of densely grafted brush copolymers by "grafting through" the macromonomers, the lower molecular weight PEOMA (MWav = 300 g/mol, DPPEO = 5) was also employed in a "grafting from" reaction using a well-defined multifunctional macroinitiator poly(2-(2-bromopropionyloxy)ethyl methacrylate) (PBPEM, M-n,M-app = 82 x 10(3) g/Mol, M-w/M-n = 1.16, degree of polymerization of backbone DPb = 428). This procedure allowed the preparation of densely double-grafted brush copolymers with various degrees of polymerization of the side chains (DPsc = 12-43). Attempts to prepare double-grafted brushes with DPsc > 50 or to use a macromonomer with a longer PEO chain (MWav = 1100 g/mol, DPPEO = 23) in the "grafting from" reaction resulted in formation of a cross-linked gel. Both the cross-linked mono- and double-grafted brush copolymers are examples of a new class of elastomeric materials with soft rubbery properties (G' similar to 10(4) Pa).