文献类型：期刊文献

英文题名：Studies of UV crosslinked poly(N-vinylpyrrolidone) hydrogels by FTIR, Raman and solid-state NMR spectroscopies

作者：Zhu, Xingfeng[1]; Lu, Ping[1]; Chen, Wei[2,3]; Dong, Jian[1,2]

机构：[1] School of Chemistry and Chemical Engineering, Shaoxing University, Shaoxing 312000, China; [2] State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, China; [3] Department of Polymer Science and Engineering, Nanjing University, Nanjing 210093, China

年份：2010

卷号：51

期号：14

起止页码：3054

外文期刊名：Polymer

收录：EI(收录号：20103013094479)、Scopus(收录号：2-s2.0-77954816404)

语种：英文

外文关键词：Free radicals - Light polarization - Nuclear magnetic resonance spectroscopy - Medical applications - Free radical polymerization - Fourier transform infrared spectroscopy - Crosslinking - Gelation

外文摘要：Poly(N-vinylpyrrolidone) (PVP) hydrogels have become increasingly important materials for pharmaceutical and biomedical applications. UV-light initiated oxidative crosslinking of PVP represents a novel method for producing PVP based hydrogel materials. However, the mechanism of the gelation by this approach is poorly understood. In this study, the reaction mechanism for the crosslinking process is investigated by FTIR, Raman, and solid-state CP/MAS NMR techniques. Both FTIR and Raman spectra indicate that in the process of free radical oxidative crosslinking, the pyrrolidone ring is partially transformed into a succinimide ring. Solid-state NMR data have confirmed this change, and provided evidence that stable intermediates of 4-hydroperoxy-pyrrolidone (PVP-OOH) and its accompanied 4-hydroxy-pyrrolidone (PVP-OH) are formed. The pyrrolidone hydroperoxide intermediate can account for the efficient crosslinking, producing a sufficient level of macroradicals to form stable hydrogels. ? 2010 Elsevier Ltd.