The Modifying And Assembly Of Hyperbranched Polymer

Hyperbranched PEI is a highly branched polymer, having a good solubility. It have a lot of amino in the end of PEI chain. Due to novel structure, unique properties and potential application prospect, this polymer attracts common attention from science and industry. Using the characteristics of chain end more amino, make small molecules having certain function grafted on the PEI. The Hyperbranched polymer needed can be synthesised.This thesis with the hyperbranched PEI as the core, the amino end of the PEI was made into two modifying, mainly including the following two aspects:(1) With L-Asp as materials, using the NCA hot open ring-opening polymerization, we make the L-Asp grafted on the chain of the hyperbranched PEI. The polymer was characterized by NMR. This amphiphilic polymer which is a reverse micelle in organic solvent, could absorb some small molecules such as methyl orange. It is a good drug carrier. In the water, The polymer could self-assembly micelles. This micelle is a core-shell structure, with PEI as a positively charged shell. So it could complex the negatively chanrged DNA. And in the process of transfection, the micelle could protect DNA molecule. It is also used a new gene carrier.(2) Using the advantage of the hyperbranched PEI end having more amino, we make the Iodine fluorinated benzene grafted on the chain of the hyperbranched PEI. This polymer also could absorb certain small molecules. Layer-by-Layber assembly of polymer and poly(4-vinylpyridin) was carried out in organic solvent. So we get the LBL multilayer films based on the halogen bonding which absorbs small molecules. It is a new kind of functional membrane assembly technology.