Study On Synthesis And Properties Of Hyperbranched Polystyrene-based And Hyperbranched Polyethylene-based Polymers

Hyperbranched polystyrene-based and hyperbranched polyethylene-based polymers possess 3 dimensional topology and special properties. They have promising potential application for burning rate promoter and drug transporter. The synthesis, characterizations and properties of hyperbranched polystyrene-based or hyperbranched polyethylene-besed polymers were studied in this thesis.A chlorine containing hyperbranched polystryrene (HBPS) was prepared by using self-condensing atom transfer radical polymerization (SC-ATRP). Two ferrocene based hyperbranched polystryrenes with different content of ferrocene units were prepared through further substitution reaction. The obtained HBPS-Fcs were characterized by using 1H NMR, FT-IR and GPC. Electrochemistry properties of HBPS-Fc were studied by using CV. As the results showed that only one kind of redox center was located in HBPS-Fc. It was found that the CV process of HBPS-Fc was affected by reaction rate of electrode and mass diffusion in DCM. Thermo-stability of HBPS-Fc was studied by using DSC. The obtained HBPS-Fcs had relatively good thermo-stability. The effects of HBPS-Fc on thermal decomposition of perchloric acid (AP) were studied. Decomposition temperature of AP was decreased by addition of HBPS-Fc. The anti-migration property of HBPS-Fc in propellant simulator was studied. It was found that HBPS-Fc had better anti-migration property than ferrocene. The obtained HBPS-Fcs are promising burning rate promoters.A graft copolymer hyperbranched polystyrene-g-poly[(N,N-dimethylamino) ethyl acrylate] (HBPS-g-PDMAEMA) was prepared through grafting PDMAEMA on HBPS by using ATRP. The obtained HBPS-g-PDMAEMA was characterized by using 1H NMR and GPC. The phase transition behavior of HBPS-g-PDMAEMA in aqueous solution was investigated. The size of HBPS-g-PDMAEMA nanoparticle was increased with the increase of HBPS-g-PDMAEMA concentration. The mophology of HBPS-g-PDMAEMA nanoparticle was observed by using TEM and the nanoparticle was nonuniform. The pH sensitivity of HBPS-g-PDMAEMA nanoparticle in aqueous soluiton was investigated. No phase transition of HBPS-g-PDMAEMA nanoparticle has been observed in acidic solution. As increaseing the pH value, the size of nanoparticle was decreased. The effect of NaCl concentration on size of HBPS-g-PDMAEMA nanoparticle was investigated. The size of nanoparticle was decreased with increasing NaCl concentration. The ability of HBPS-g-PDMAEMA nanoparticle for loading small molecules was investigated by using pyrene as model small molecule. The environmentally located polarity of pyrene loaded in HBPS-g-PDMAEMA nanoparticle was larger than it dispersed directly in water. It indicated that the produced nanoparticle was capable of loading small molecules. The ability for loading small molecules was further investigated by using nile red(NR) and camptothecin(CPT) as model small molecules. It was found that the fluorescence intensity of NR and CPT was increased with increasing concentration of HBPS-g-PDMAEMA. It further confirmed the HBPS-g-PDMAEMA nanoparticle was capable of loading hydrophobic small molecules. The HBPS-g-PDMAEMA is a promising drug transporter. The HBPS-g-PDMAEMA nanoparticle has potential application for drug carrier.Three hyperbranched polyethylenes (HBPEs) with different molecular weight were prepared from ethylene polymerization catalyzed by a-diimine nickel catalyst. The obtained polyethylenes were characterized by using 1H NMR and GPC. The thermo-properties of HBPE were studied by using DSC. HBPE/F-127(poly(ethylene oxide)-b-poly(propylene oxide)-b-poly(ethylene oxide)) carrier was prepared from self-assemble. The micelle was thermo-sensitive and the size of carrier was decreased with increasing temperature. The ability of the obtained carrier for loading small molecules was further investigated by using NR and CPT as model small molecule. The fluorescence intensity of NR or CPT was increased with increasing carrier concentration, which indicated that HBPE/F-127 carrier was capable of loading hydrophobic small molecules. HBPE/F-127/NR was prepared from self-assembly. It was found that the addition of NR could affect thermo sensitivity of HBPE/F-127 carrier and the size of HBPE/F-127/NR was increased. The HBPE/F-127 carrier has potential application for drug carrier.Two graft copolymers hyperbranched polyethylene-g-poly(tertbutyl methacrylate)s (P(E-co-BPEA)-g-P’BMAs) were prepared by combination of chain walking, RAFT polymerization and thiol-bromo reaction. An amphiphilic graft copolymer hyperbranched polyethylene-g-poly(methacrylic acid) (P(E-co-BPEA)-g-PMAA) was prepared through further hydrolysis of P(E-co-BPEA)-g-PtBMAs. The obtained P(E-co-BPEA)-g-PtBMAs and P(E-co-BPEA)-g-PMAA were characterized by using’H NMR and GPC. It was approved from DLS that P(E-co-BPEA)-g-PMAA could form unimolecular micelle in aqueous solution. The ability of P(E-co-BPEA)-g-PMAA micelle for loading small molecules was investigated by using pyrene as model small molecule. The environmentally located polarity of pyrene loaded in P(E-co-BPEA)-g-PMAA unimolecular micelle was larger than it dispersed in water. It indicated that P(E-co-BPEA)-g-PMAA unimolecular micelle was capable of loading hydrophobic small molecules. The ability for loading CPT, a anti-cancer drug, was further investigated. It indicated that P(E-co-BPEA)-g-PMAA may have usage in application for drug carrier.