| Hyperbranched polyethyleneimine(HPEI)is widely used in different fields because of its good water solubility property and the characteristic that a large number of easily modified amine groups are existed in the hyperbranched structure and so on.In this thesis,a series of functionalized hyperbranched polyethyleneimine polymers were obtained by modifying and functionalizing polyethyleneimine with a molecular weight of 10000,and these polymers were applied in pesticide sustained-release,copper ion detection and control of a-calcium sulfate hemihydrate crystal growth.The detailed contents are as follows:1.Summarized the synthetic approaches,characterization,functionalization and modification methods as well as applications of polyethyleneimine,then put forward our research subject.2.A series of amphiphilic hyperbranched polyethyleneimine functional polymers with different substituents and substituted ratios were designed and synthesized by amidation and oxidation reactions of hyperbranched polyethyleneimine with n-butyric acid,n-octanoic acid,lauric acid,palmitic acid,or phenylbutyric acid,and their applications in pesticide sustained-release were studied.Their structures were characterized by 1H NMR and FT-IR spectra,and their substituted ratios were also calculated.Some selected polymers were used to prepare benzothiostrobin-loaded micelles by self-assembly,and their particle size and morphology were characterized by DLS and TEM.Moreover,the drug-loading efficiency(DL)and encapsulation efficiency(EE)of drug-loaded micelles were calculated by HPLC data,and showed that different substituents and substituted ratios of the polymers lead to different drug-loading and encapsulation efficiency.The DL and EE can be further increased by oxidizing the polymers,for example,the drug-loading and encapsulation efficiency of the micelles prepared by polymer HOPEI-BDS(1/4)were 24.2%and 72.6%respectively,which were the highest value.Finally,the sustained-release behavior of the drug-loaded micelles was studied,and it is found that the benzothiostrobin-loaded micelles indeed showed sustained-release properties to some extent.3.Nonconjugated copolymer nanoparticles(HOPEI-F CPs)with good water solubility,high stability and blue fluorescence emission property were prepared by H2O2 oxidation and subsequent cross-linking of formaldehyde from hyperbranched polyethylenimine,and their applications in copper ion detection were studied.It is found that the fluorescence intensity of HOPEI-F CPs was closely related to the synthetic pH value,and the strongest fluorescence intensity was obtained at pH 5.14.The HOPEI-F CPs showed high selectivity and sensitivity to copper ion with a detection limit of ca.13 nM in aqueous medium,indicating potential applications in chemical and biological fields.4.A hyperbranched polyethyleneimine derivative(HPEI-PA)containing catechol functional groups was designed and synthesized by amidation reaction of hyperbranched polyethyleneimine with 3,4-dihydroxybenzoic acid,and used to control the a-calcium sulfate hemihydrate crystal growth from dehydrate calcium sulphate.The structure of HPEI-PA was characterized by 1H NMR and FT-IR spectra,and the morphology and properties of a-calcium sulfate hemihydrate crystal were characterized by SEM,XRD,TG-DSC and FT-IR spectra.It is found that the concentration of HPEI-PA and the pH value have a great influence on the morphology and the length/width(l/w)ratio of a-calcium sulfate hemihydrate crystal,the best morphology of a-calcium sulfate hemihydrate crystal was obtained at concentration of 4 mg/mL and pH 5.5.Moreover,the mechanism of HPEI-PA controlled crystal growth of a-calcium sulfate hemihydrate was also discussed.In addition,the dry compression strength and bending strength test results showed that the smaller length/width(l/w)ratio,the better mechanical performance,and the corresponding maximum values were 14.35 MPa and 35.70 Mpa,respectively. |
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