Synthesis And Properties Of Block And Graft Copolymers Containing Poly(Ethylene Oxide) (PEO) Block

In this thesis, some novel well-defined block or graft copolymers withpoly(ethylene oxide) as main chain were successfully prepared through different waysand they were characterized by NMR and GPC etc. So their complex structures can begot conveniently.1. PEO was esterified with 2-bromoisobutyryl bromide to produce the ATRPmacroinitiator with pending bromoisobutyryl groups [poly(ethylene oxide)CATRP)].Subsequently, the latter initiates the polymerization of styrene (St), acrylonitrile (AN),tert-butyl acrylate (tBA) and 2-(dimethylamino) ethyl methacrylate (DMAEMA)respectively to form the corresponding well-defined amphiphilic block copolymerPEO-b-PS, PEO-b-PAN, PEO-bPtBA and PEO-b-PDMAEMA.2. The diblock copolymer PAN-b-PEO can self-assemble into spherical micelles indilute solution and SiO₂ can be embedded by PEO-b-PAN. We can see their differentmorphologies by TEM. PEO-b-PDMAEMA can also the self-assemble into micelles,The morphologies of the copolymers are related to pH and the concentration of NaClin the solution.3. The coordination-insertion ring-opening polymerization ofε-caprolactone andlactide with PEO were completed by initiation of hydroxyl groups of the PEO in thepresence of Sn(Oct)₂. Thus, the amphiphilic copolymers PEO-b-PCL and PEO-b-PLA were obtained.4. Some novel well-defined graft copolymers of poly(ethylene oxide) as main chainis successfully prepared by combination of anionic and atom transfer radicalpolymerization (ATRP). The glycidol is protected by ethyl vinyl ether first to form2,3-epoxypropyl-1-ethoxyethyl ether (EPEE), then copolymerized with EO byinitiation with the mixture of diphenylmethylpotassium and triethylene glycol to givethe well-defined poly(EO-co-EPEE). The latter is hydrolyzed in the acidic conditions,so the linear poly(EO-co-Gly) can be got. Then coordination-insertion ring-openingpolymerization of lactide with poly(EO-co-Gly) was completed.