Reverse atom transfer radical polymerization of methyl methacrylate initiated by AIBN/FeCl3/isophthalic acid system

The reverse ATRP of MMA using AIBN/FeCl₃/ isophthalic acid as the initiating system was successfully performed. The new initiating system can be used to synthesize PMMA with high molecular weight and narrow polydis- persity index. The polymerization shows ‘living’/controlled characteristics. Compared with other initiating system used in reverse ATRP, the easy availability and non-toxicity of isophthalic acid make it very attractive.     

PDMAA/Clay纳米复合水凝胶的制备与性能

以无机黏土为交联剂,采用偶氮二异丁腈(AIBN)为引发剂制备了新型的聚N,N ＇-二甲基丙烯酰胺/黏土(PDMAA/Clay)纳米复合水凝胶,作为对比,采用过硫酸钾(KPS)为引发剂制备了相对应的水凝胶.对两种纳米复合水凝胶的结构、形态、溶胀行为和力学性能等进行了研究.试验表明,黏土的结晶结构均已被破坏,黏土规整的片层被剥离并在凝胶中无序分布,起到交联剂的作用.随着黏土含量的增加,水凝胶的溶胀速率和溶胀度降低.采用AIBN制备的PDMAA/Clay水凝胶具有更好的韧性及更高的断裂强度,其断裂伸长率可达1 800％以上,而KPS制备的水凝胶的断裂伸长率在1 200％左右.     

Reverse atom transfer radical polymerization of methyl methacrylate initiated by AIBN/FeCl3/isophthalic acid systèm

The reverse ATRP of MMA using AIBN/FeCl₃/ isophthalic acid as the initiating system was successfully performed. The new initiating system can be used to synthesize PMMA with high molecular weight and narrow polydispersity index. The polymerization shows ‘living’/controlled characteristics. Compared with other initiating system used in reverse ATRP, the easy availability and non-toxicity of isophthalic acid make it very attractive.     

Fe(2- EHA)3/Al(i- Bu)3/AIBN催化异戊二烯聚合的研究

研究了Fe(2 - EHA)3/Al(i - Bu) 3/AIBN催化体系下异戊二烯的聚合行为,考察了催化剂组分配制方式和聚合条件对催化活性、聚合物的微观结构和分子量及其分布的影响.结果表明,该体系聚合异戊二烯具有高活性、聚合物分子量高和不含凝胶等特点.所得聚异戊二烯顺-1,4、3,4-、1,2-结构单元分别为46 ～...     

偶氮异丁腈解离反应的途径和机理解析

用量子力学方法对偶氮异丁腈(AIBN)分解反应的机理进行了系统的理论研究.应用密度泛函理论在B3LYP/6-311G*,B3LYP/6-311+G*和BHandH/6-31+G**水平上对此反应过程中所涉及的反应物、过渡态、中间体、复合物和产物的几何结构和能量进行优化计算,并给出了反应详细的势能面信息和机理解析.结果表明,偶氮异丁腈在基态下采取两键(三体)同步解离的模式进行自由基热分解反应,即Me2(CN)C-N=N-C(CN)Me2→2Me2(CN)C.+N2;在三态(诱导激发)下,则进行两键(三体)异步解离,即Me2(CN)CN=N—C(CN)Me2→Me2(CN)—CN=N…C(CN)Me2→2Me2(CN)C.+N2.计算的活化能与实验结果吻合.