淀粉系高吸水性树脂反应中间体稳定性及反应活性的量子化学研究  

Quantum Chemistry Study on Stability and Reactivity of Reactive Intermediate of Starch Super-water-absorbent Resin

作　　者：颜力楷[1] 兰亚乾[1] 苏忠民[1] 仇永清[1] 邵琛[1] 李宝利[1] 王荣顺[1] 

机构地区：[1]东北师范大学化学学院功能材料化学研究所,玉米淀粉深加工研究中心,长春130024

出　　处：《高等学校化学学报》2003年第2期297-300,共4页Chemical Journal of Chinese Universities

基　　金：吉林省科技厅基础项目基金 (批准号 :2 0 0 10 344 )资助

摘　　要：运用 ab initio UHF方法和 DFT UB3LYP方法在 6 -31 G基组水平下对淀粉系高吸水性树脂反应中间体的模型体系进行几何构型优化 .针对每类自由基对应得到的两种典型的构象异构体 ( 1 a,1 b和 2 a,2 b) ,进行稳定性和反应活性分析 .构型 1 a和 2 b的总能量相对较低 .比较 4个模型体系的前线分子轨道 ,构型 1 a的能隙较小 ,同时 HOMO能量较高 ,易给出电子 ,LUMO能量较低 ,易得电子 ,有利于电子转移 ,因而有较好的反应活性 .自由基自旋密度主要集聚在 C2或 C3上 ,未有较大弥散 ,同时也是前线 MO主要布居位置和重要的反应活性部位 .对构型 1 a与丙烯酸模型分子形成的复合物分析表明 ,两者的反应未经过过渡态 ,在瞬间即可完成 .The model geometries of reactive intermediates of the super-water-absorbent resin were determined by using ab inito UHF and density functional theory UB3LYP with 6-31G basis sets. The stability and reactivity of the two kinds of typical conformation isomers(1a, 1b and 2a, 2b) with their free radicals are obtained and analyzed. The calculation results show that the total energy of isomers 1a or 2b is lower. The energy gap of isomer 1a is smaller comparing with the frontier molecular orbitals of four model systems. HOMO energy of 1a is higher, so it is easy to lose electrons. LUMO energy is lower and it is easy to receive electrons, which benefits the charge transfer. The spin density of free radical mostly concentrates on C2 or C3 and has no large diffusion. They are the key part of reactivity. The analysis to the complex with isomer 1a and acrylic acid molecule indicate that the polymerization reaction is easy to finish because of giving out heat.

关 键 词：淀粉 反应中间体 稳定性 反应活性 量子化学 高吸水性树脂 自由基 Abinito DFT 几何构型 优化 复合物 核技聚合 丙烯酸 

分 类 号：TQ321[化学工程—合成树脂塑料工业] O636.12[理学—高分子化学]