A novel α,ω‐heterofunctional poly(ethylene oxide) (PEO) macromonomer possessing methacryloyl and thienyl end groups was prepared by ring‐opening polymerization of ethylene oxide initiated by potassium thienylethoxide and termination of the living PEO ends with methacryloyl chloride. Incorporation of methacryloyl and thienyl groups was confirmed by free‐radical and oxidative polymerization processes, respectively, and by means of 1H NMR analysis.
Synthesis of poly(ethylene oxide) (PEO) macromonomers carrying a methacyloyl group in one end, and N, N-dimethyl amino, thiophene, styryl and vinyl ether functional groups in the other end was desribed. The general synthetic strategy is based on the living anionic polymerization of ethylene oxide initiated with functional potassium alcoholates, followed by reaction with methacyloyl chloride. These macromonomers were further utilized in various macromolecular architectures through via concurrent or selective thermal free radical, oxidative and photoinitiated free radical and cationic polymerization methods. The use of this synthetic route to prepare graft copolymers possessing completly and perfectly alternating PEO side chains using charge-transfer-complex polymerization was also demonstrated. 相似文献
A series of block copolymers bearing a single amino in-chain functionality was synthesized via anionic polymerization of styrene and ethylene oxide. By means of both a conventional and a continuous setup, living polystyrene was quantitatively end functionalized with an oxirane (DBAG) prior to the polymerization of the poly(ethylene oxide) segment. The in-chain amine was conjugated with a fluorescent dye. 相似文献
A procedure to prepare nonionic reactive surfactants with different polymerizable groups is described. The synthesis involves the initiation of living anionic ring-opening polymerization of ethylene oxide and propylene oxide (for the hydrophilic part and the hydrophobic part, respectively) by a potassium salt prepared from the stoichiometric reaction of potassium hydride and diethylene glycol monomethyl ether. The resulting anion is reacted with chloride compounds (methacryloyl, allyl, vinylacetoyl) and maleic anhydride, as well as with isobutanoyl chloride, leading to a nonpolymerizable compound having a similar structure. Then, it was possible to produce a range of reactive surfactants more or less reactive with the monomers. These surfactants are expected to be used further in emulsion polymerization processes (styrene and butyl acrylate). This procedure gives good control of both hydrophobic and hydrophilic parts, and the end reaction for the different functionality of surfmers is quite quantitative. All the surfactants were characterized by size-exclusion chromatography and 1H NMR. Physicochemical properties, such as the critical micellar concentration and the specific area, were also measured. 相似文献
Functional poly(ethylene oxide) stars were prepared by free‐radical copolymerization of poly(ethylene oxide) macromonomers with divinylbenzene in water. The poly(ethylene oxide) arm was prepared by anionic polymerization using 2‐[2‐(N,N‐dimethylamino)ethoxy]ethanol potassium alkoxide as the initiator. These functional stars were converted into peripherally charged stars by quaternization of the peripheral tertiary amino groups with methyl iodide. 相似文献
Functionalized poly(ethylene oxide) (PEO) macromonomers (alpha -tertiary amino and omega -methacryloyl groups) were prepared by ring-opening polymerization of live PEO anions end-capped with styrene oxide using 2-[2-(N ,N -dimethylamino)-ethoxy]ethanol potassium alkoxides as an initiator with methacryloyl chloride. PEO brushes were synthesized by free-radical homopolymerization of such PEO macromonomers. These brushes were converted into peripherally charged brushes by quaternization. We studied the solution properties of both types of brushes from the viewpoint of charge effect. It was found from dynamic light scattering (DLS) that the polymer brushes formed a single macromolecule in solution due to crowding of side chains. It was speculated from angular dependence measurements that the polymer brushes with large aspect ratios took a geometrical anisotropic conformation such as a cylinder. In methanol with a low dielectric constant, radius of gyration (R(G)), and cross-sectional radius of gyration (R(G,C)) of the polymer brushes with charged side chains were smaller than those of the polymer brushes without charges. In a solvent with a low dielectric constant such as methanol, ionic groups do not dissociate and condense. On the other hand, these physical values in an aqueous solution were somewhat larger than those of the polymer brushes without charges. In water with a high dielectric constant, peripherally charged brushes were strongly stabilized by electric double layers. 相似文献
A universally significant method,which combines the anionic polymerization with photoinduced charge transfer polymerization,for preparation of soluble star ABC triblock copolymer of ethylene oxide,styrene and methyl methacrylate,was described.The poly(ethylene oxide) (PEO) block was formed by initiation of phenoxy an-ions using p-aminophenol protected by Schiff's base as the parent compound Then the charge transfer system composed of PEO chains with deprotected-amino end groups and benzophenone initiated the polymerization of styrene and methyl metnacrylate sequentially under UV irradiation.The formed star triblock copolymer of styrene,ethylene oxide and methyl methacrylate could be purified by thin-layer chromatography (TLC) and characterized by IR,1H NMR,GPC (gel permeation chromatogrphy) and PGC (pyrolysis gas chromatography). 相似文献
Polyethylene oxide with sulfadiazine and hydroxyl end groups (PEOsf) were prepared by anion ring-opening polymerization of ethylene oxide initiated by sodium 4-amino-N-(2-pyrimidinyl)benzene sulfonamide (SF-Na). The product was characterized in detail by NMR, IR, GPC and DSC. Its molecular weight and molecular weight distribution are in the range of 1200-1 500 and 1.04-1.06 respectively, and the latter is nearly monodistribution. The trace of the moisture from air could accelerate the polymerization, and the mechanism is discussed. 相似文献
Functional poly(ethylene oxide) star polymers possessing a tertiary amino group at each arm end were prepared by free-radical copolymerization of poly(ethylene oxide) macromonomers with divinylbenzene (DVB) in water or ethanol. The poly(ethylene oxide) arm was prepared by anionic polymerization using 2-[2-(N,N-dimethylamino)ethoxy]ethanol potassium alkoxide as the initiator. The star polymers had narrow molecular weight distribution. The arm number was controlled by varying the feed ratio [DVB]/[M], the initial concentration of macromonomer [M], and solvent media. The branching factor g' in methanol ([eta]S/[eta]L are the intrinsic viscosities of the star and linear molecules, respectively) exhibited a power-law dependence on the arm number, f, with a negative exponent. This means that the dimensions of a star were in agreement with the Daoud-Cotton scaling model. 相似文献
Polyethers of low and medium molecular weight containing at both ends stable ionic groups (phosphonium ions) were obtained by living cationic polymerization of tetrahydrofuran initiated by difunctional initiator, trifluoromethanesulfonic anhydride, followed by termination with triphenylphosphine. It was shown, that products contain significant quantities of low molecular weight diphosphonium salt; a plausible explanation is presented. Alternative approach to the synthesis of diionically terminated polyethers was based on the conversion of hydroxyl end-groups of polyether diols, which can be obtained by cationic Activated Monomer (AM) polymerization of e.g. oxiranes, into phosphonium ion end-groups. Using this approach, poly(ethylene oxide)'s with Mn ranging from 300 to 3400, terminated at both ends with stable ionic groups, were prepared and characterized. Measurements of NMR relaxation times and viscosity measurements provide the evidence for the aggregation of ionic end-groups. The potential applications of inter- and intramolecular aggregation are discussed. It is shown, that intramolecular aggregation of ionic terminal groups in low molecular weight poly(ethylene oxide) leads to cyclic structures resembling crown ethers and showing comparable efficiency for complexing cations. 相似文献
Amphiphilic graft copolymer of polystyrene (PS) as backbone and poly(ethylene oxide) (PEO) as branch chain was prepared by Decker-Forster reaction. PEO with Schiff's base end group (PEOs) was obtained by ring-opening polymerization of ethylene oxide (EO) initiated with protected potassium aminoethoxide, and then alkylated with chloromethylated polystyrene (c-PS). A graft copolymer with high grafting efficiency was derived by hydrolysis of the above-mentioned product. 相似文献