低代数聚丙烯亚胺树形分子的合成与表征

对聚丙烯亚胺树形分子的合成进行了研究。通过优化反应条件 ,如提高反应温度、增大反应物浓度、加入少量醋酸作为催化剂、选择氨 甲醇作为还原溶剂 ,提出了一条合成结构较为精确 ,可以最大程度减少或避免副反应的聚丙烯亚胺树形分子的合成路线。红外光谱表明优化条件下所得 0 5代聚丙烯亚胺树形分子反应完全 ,有利于结构增长 ;滴定法表明在氨 甲醇溶剂下还原所得 1 0代聚丙烯亚胺树形分子中伯胺基的摩尔分数为x (NH2 ) =85 % ,比在甲醇条件下所得结果 [x(NH2 ) =76 % ]有较大提高。1H核磁共振、元素分析也表明所合成的低代数聚丙烯亚胺树形分子结构精确 ,达到了分子设计的目的。

Synthesis and Characterization of Low Generation Poly(propyleneimine) Dendrimer

Synthesis of poly(propyleneimine) dendrimer was studied.By optimizing reaction conditions,such as increasing reaction temperature and concentration of reactant,introducing a little acetic acid as catalyst and choosing ammonia/methanol as solvent,a preparative route was developed in which the poly(propyleneimine) dendrimer with relatively perfect stucture was obtained and the side reactions were suppressed to a considerable degree or even eliminated.Infrared spectrum showed that 0.5 generation poly(propyleneimine) dendrimer was obtained by reacting completely under optimum conditions,which was in favor of the growth of structure.Titration showed that 1 0 generation poly(propyleneimine) dendrimer obtained in ammonia/methanol contained 85 percent primary amine,which was better than that obtained in methanol. 1H nuclear magnetic resonance and elementary analysis also showed that structures of low generation poly(propyleneimine) dendrimer were perfect and in accord with the expected molecular structure.