College of Science, China University of Petroleum, Beijing 102249, China.
College of Science, China University of Petroleum, Beijing 102249, China.
Carbohydr Polym. 2015 Mar 6;117:247-254. doi: 10.1016/j.carbpol.2014.09.033. Epub 2014 Sep 23.
A novel initiator system containing KMO4, HIO4, and H2SO4 for synthesizing grafting starch copolymers is reported. In this system, KMnO4 was used to oxidize the primary hydroxyl group to aldehyde group of glucose in the starch, and the formed aldehyde group reacted with Mn(4+), Mn(3+) to afford starch free radical. At the same time HIO4 perform as the oxidant to open the C2C3 bond of glucose ring in starch to form two more aldehyde groups, and then two more free radicals are generated. As a result one glucose unit could provide ultimately three active sites for starch grafting reaction. Graft copolymers with a higher grafting ratio and grafting efficiency could be obtained by using the composite initiation system than the KMnO4/H2SO4 initiation system. The grafting of polyacrylamide onto the corn starch backbone was confirmed by viscometry, elemental analysis, infrared spectroscopy, nuclear magnetic resonance, X-ray diffraction and scanning electron microscopy.
本文报道了一种新型引发体系 KMO4、HIO4 和 H2SO4 用于合成接枝淀粉共聚物。在该体系中，KMnO4 用于将淀粉中葡萄糖的伯羟基氧化为醛基，形成的醛基与 Mn(4+)、Mn(3+)反应生成淀粉自由基。同时，HIO4 作为氧化剂打开淀粉中环的 C2C3 键，形成两个更多的醛基，然后再生成两个自由基。因此，一个葡萄糖单元最终可以为淀粉接枝反应提供三个活性位点。与 KMnO4/H2SO4 引发体系相比，使用复合引发体系可以获得接枝率和接枝效率更高的接枝共聚物。通过粘度法、元素分析、红外光谱、核磁共振、X 射线衍射和扫描电子显微镜证实了丙烯酰胺接枝到玉米淀粉主链上。
