Modification Of Hyperbranched Polyethylenimine And Its Fluorescent Properties

In this dissertation,we synthesized a series of compounds by modifying hyperbranched polyethylenimine（HPEI）with monomethoxy polyethylene glycol（mPEG）,isobutyric anhydride,caproic anhydride or 2-（（4-（1,2,2-triphenylvinyl）phenoxy）methyl）oxirane（TPE-epoxy）with.The fluorescence properties of these compounds were measured.The HPEI modified with PEG was named HPEI-g-PEG.¹H-NMR proved the successful preparation of HPEI-g-PEG and gave the information of degree of substitution of PEG.The UV-vis measurement demonstrated that the modification with PEG could obviously affect the UV-vis absorbance of the polymer.The fluorescence of the polymer solution could be influenced by the PEG degree,concentration of the polymer,temperature,pH,oxidation time and the molecular weight of HPEI.HPEI-g-PEG with 26%of substitution PEG was named as HPEI-g-PEG₂₆.HPEI-g-PEG₂₆ was modified with isobutyric anhydride or caproic anhydride to get H-P₂₆-C₄ or H-P₂₆-C₆.These polymers were used as capsules to accommodate Nile red（NR）molecules.And the condition of the best capacity was detected by changing the concentration of both polymer and NR,the temperature,the kinds of anhydride and the degree of anhydride.We also synthesized H-P₂₆-TPE-C₄ which ended with TPE and isobutyl.And the fluorescence difference between H-P₂₆-TPE-C₄ and H-P₂₆-C₄ with NR was studied.