Ajiro Hiroharu, Kan Kai, Akashi Mitsuru
J Nanosci Nanotechnol. 2017 Jan;17(1):837-41. doi: 10.1166/jnn.2017.12451.
Hydrogel preparations using poly(N-vinylformamide) (PNVF) and poly(N-vinylacetamide) (PNVA), which are composed of non-conjugated vinyl monomers, N-vinylformamide (NVF) and N-vinylacetamide (NVA), were investigated without chemical crosslinkers. Hydrogen bonding interaction between the polymers and poly(ethylene glycol) have been firstly attempted to result in unstable film, which is easily soluble in water. On the other hand, the simple thermal treatment of the PNVF films at 200 °C for several hours produced the hydrogels after water immersion, although PNVA did not produce any hydrogels under the same condition. The swelling ratios of the formed hydrogel ranged from 100 to 250. The analysis of the supernatant reveals the structural change at alpha proton of PNVF. Furthermore, the decrease of molecular weights were observed by SEC analysis when the hydrogels formed. The possible mechanism of the crosslinking reaction is also discussed. The present study provides the novel method to prepare PNVF hydrogels without the use of chemical crosslinkers.
对使用由非共轭乙烯基单体N-乙烯基甲酰胺（NVF）和N-乙烯基乙酰胺（NVA）组成的聚（N-乙烯基甲酰胺）（PNVF）和聚（N-乙烯基乙酰胺）（PNVA）的水凝胶制剂进行了研究，且未使用化学交联剂。首先尝试了聚合物与聚乙二醇之间的氢键相互作用，结果得到不稳定的薄膜，该薄膜易溶于水。另一方面，将PNVF薄膜在200℃下简单热处理数小时，在水浸后产生水凝胶，尽管PNVA在相同条件下未产生任何水凝胶。形成的水凝胶的溶胀率在100至250之间。上清液分析揭示了PNVF的α质子处的结构变化。此外，通过尺寸排阻色谱（SEC）分析观察到形成水凝胶时分子量降低。还讨论了交联反应的可能机制。本研究提供了一种无需使用化学交联剂制备PNVF水凝胶的新方法。
