PAMAM体型缩聚物的制备及其性能研究

以分子末端带有多官能度活泼端基的PAMAM等为原料 ,通过缩聚反应制备了一类新型体型缩聚物 .借助X射线光电子能谱仪 (XPS)对制备的体型缩聚物进行分析 ,利用其化学分析电子光谱 (ESCA)中碳元素价态的拟合数据判断体型缩聚反应进行的程度 ,数据表明酯基碳 (—COO)拟合峰已基本消失 ,说明其与氨基缩合反应转化为酰胺基 (—CON) ,且反应进行的比较彻底 .通过体型缩聚物在乙醇、正己烷、甲苯、氯仿、异丙醇、乙酸、甲酸、去离子水中进行溶胀试验 ,发现其在甲酸作为溶剂体系中的溶胀比出现最大值 ,根据溶度参数的意义估测体型缩聚物的溶度参数约为δ2 =2 7 6 (MJ m3) 1 2 (即甲酸的溶度参数 ) .对原料PAMAM以及制备的体型缩聚物进行DSC分析 ,发现制备体型缩聚物的玻璃化转变温度 (Tg)有了较大提高 ,从初始原料PAMAM的负值提高到 4 8℃左右 .

PREPARATION AND CHARACTERIZATION OF PAMAM DENDRIMER POLYCONDENSATES

A novel class of three-dimensional polycondensates were prepared with PAMAM dendrimers having terminal multi-functional groups and other compounds,on the basis of polycondensation mechanism.The X-ray electron spectrometer (XPS) was resorted to analyze the polycondensates,and the fit data of carbon element value in Electron Spectroscopy for Chemical Analysis (ESCA) was utilized to estimate the extent of polycondensation.The fit peaks of carbon of ester groups (—COO—) were almost disappeared and they might reacted with amido and formed acylamide (—CON),therefore the polycondensation reactions were almost completely.The swelling tests of polycondensates were carried out in the hexane,toluene,chloroform,isopropanal,acetic acid,ethanol,formic acid and water.It was found that the max swelling value reached in the formic acid.Hence the solubility parameter of polycondensates (δ_2) was about 27.6 (MJ/m~3)~(1/2) (as the same as formic acid ) according to the meaning of δ_2.The DSC analysis of the raw PAMAM dendrimer and the polycondensates demonstrated that the glass-transition temperature (T_g) of polycondensates had been great improved,which from subzero temperature of raw materials to 48℃.