高纯度树状大分子聚酰胺-胺的合成与表征

Synthesis and Characterization of High Purity Polyamidoamine Dendrimers

以乙二胺为核,通过Michael加成,与丙烯酸甲酯交替反应,合成了0.5代到5.0代聚酰胺-胺树状大分子。利用傅里叶变换红外光谱、核磁共振氢谱、液相色谱和元素分析等对各代产品进行了表征,探索了反应温度、时间及反应物配比对产物的影响,确定生成聚酰胺-胺(PAMAM)的半代产物时反应温度为25℃,整代产物时反应温度为35℃;0.5G的反应时间为18 h,1.0G、1.5G的反应时间为24 h,2.0G、2.5G反应36 h,3.0G、3.5G反应48 h,4.0G、4.5G反应3 d,5.0G反应4 d。分离提纯是树状大分子制备中遇到的最大困难,通过选择性溶剂萃取的方法对产品分离纯化,筛选出乙醚作萃取剂、甲醇作溶剂交换剂,大大提高了产品的纯度。

n0.5G^5.0G dendrimers with ethylene diamine as core were synthesized from alternating copolymeraziation of methacrylate by Michael addition reaction.The structures of all products were characterized by FTIR,1H NMR,HPLC,and elemental analysis.The influences of the reaction temperature,reaction time and ratio of reactants were investigated.The reaction temperature is 25 ℃ for the half-generations and 35 ℃ for the full-generations.The optimum reaction time is 18 h for 0.5G,24 h for 1.0G and 1.5G,36 h for 2.0G and 2.5G,48 h for 3.0G and 3.5G,3 d for 4.0 and 4.5G,and 4 d for 5.0G.The main difficulty in the synthesis is the separation and purification of the products.The results showed that the purity of polyamidoamine dendrimers was improved by solvent extraction using ether as extractant and ethanol as exchanged solvent.