Polynitroxides from Alkoxyamine Monomers: Structural and Kinetic Investigations by Solid State NMR
Polynitroxides from Alkoxyamine Monomers: Structural and Kinetic Investigations by Solid State NMR
复制标题
DOI：
10.1021/ma400351q
复制
发表时间：
2013-04-09
期刊：
影响因子：
5.5
通讯作者：
Eckert, Hellmut
中科院分区：
文献类型：
--
作者：
Behrends, Frederik;Wagner, Hendrik;Eckert, Hellmut
介绍了一种合成聚（4-甲基丙烯酰氧基-2，2，6，6-四甲基哌啶-N-氧基）（PTMA）的新方法。聚合的多分散性指数（PDI）和动力学数据表明受控反应。聚烷氧基胺的氧化C-O键断裂导致PTMA。这种转化以优异的产率发生，并且可以将预聚物的窄PDI转移到PTMA。该材料的特点是详细使用循环伏安法在解决方案和磁化率测量，以及多核固态NMR和EPR光谱。前体聚合物向多氮氧化物的转化可以方便地通过H-1和F-19监测。魔角旋转（MAS）以及C-13{H-1}交叉极化（CP）-MAS NMR。此外，在高转化率的聚合物中的氮氧侧链单元的分子间相互作用可以通过观察明显的低频偏移来检测和监测。
A novel synthetic route toward poly(4-methacryloyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl) (PTMA) is described The polymerization of alkoxyamine-based monomers by atom transfer radical polymerization (ATRP) was investigated, as the polyalkoxyamine serves as the precursor for PTMA. The polydispersity indices (PDIs) and the kinetic data of the polymerization indicate a controlled reaction. The oxidative C-O bond cleavages of the polyalkoxyamine lead to PTMA. This transformation occurs with excellent yields, and it is possible to transfer the narrow PDIs of the prepolymer to PTMA. The material is characterized in detail using cyclic voltammetry in solution and magnetic susceptibility measurements as well as multinuclear solid state NMR and EPR spectroscopies. The conversion of the precursor polymer to the polynitroxide can be conveniently monitored by H-1 and F-19. magic angle spinning (MAS) as well as C-13{H-1} cross polarization (CP)-MAS NMR. In addition, the intermolecular interaction of the nitroxide side chain units in the polymer at high conversion can be detected and monitored by the observation of pronounced low frequency shifts.