| Dendrimer is a new-type function macromolecule chemical compound of special structure and performance whose specialties are to design the molecular size,shape and functional group at the molecular level. According to its own specialties, studying systematacially the molecular structure and performance, developing the function macromolecule with new-type terminal group is an important research direction. The surface terminal group can carry on function transform. There are amido, hydroxyl, carboxyl, ester base, acylamino group, metal chelate compound etc that have already been reported at present. Because there are active sites and the spacious cavity among the center and inside of dendrimers with the dense functional group in surfacee, those make this kind of macromolecule have well enough application prospects in drug deliver, catalyst carrier, gene therapy, dye industry and membrane material etc. The thesis has introduced briefly the structure, performance, synthetic method and application of dendrimers. The dendrimers were synthesized in two steps: first, the poly(amidoamine)(PAMAM) dendrimers were prepared by divergent method with ethylenediamine as core. PAMAM was functioned with tris(tri-hydroxymethyl) amino methane and para aminobenzoic acid. A type of water-solubility dendrimer with hydroxy and carboxyl of terminal group was synthesized. The molecular structures of the product have been characterized by means of infrared spectrum(IR) aThe validity of the molecular structure of dendrimer was proved tomatch with the designing target molecular This thesis has explored tentatively the performance of dendrimers synthesized , by the structure characteristics of dendrimers. The surface tensions of half generation poly(amidoamine)(PAMAM) and dendrimers with hydroxy and carboxyl of terminal group by drop-volume method. It was found that dendrimers differed from traditional surfactants, and intermolecular aggregation did not occur. The terminal group influenced on the surface activity of dendrimers and the surface tensions approached those of water with the hydrophilicity of the terminal group more increasing. The study of dendrimer solubilization capacity on hard-dissolved guest molecule was discussed emphatically. Benzoic acid, buprofen, methyl red and disperse red 167 were choiced as hydrophobic drug model. The ability of dendrimers to increase the solubility of hydrophic drug molecules was investingated by UV-VIS spectroscopy. The dendrimers with different end groups all enhanced the solubility of model drug significantly. Due to CMC was observed, the dendrimers in water could been regarded as "unimolecular micelle". The unimolecular micelle has the similar properties to a traditional micelle, but the micellar structure stabilized in variety of solvents. The inherent stability of dendritic unimolecular micelles, as well as the ability to encapsulate guest molecules, makes them good candidates for the hard-dissolved guest molecules in the fields of medicine and dye industry. |
