The effect of the microstructure on the phase behavior of mixtures of polybutadiene (PB) and poly(ethylene-co-1-butene) (PEB) with polystyrene (PS) has been investigated. A series of PBs with 1,2-addition content ranging from 7 to 93% were synthesized by anionic polymerization, and a portion of each was subsequently hydrogenated to yield PEB. Polymer pairs with blend compositions from 10 to 90 wt % were cast from toluene for each of the 16 PS/PB pairs and 7 PS/PEB pairs. Laser light scattering was used to obtain cloud point measurements, which were then used to construct phase diagrams. It was found that, for constituent components with equivalent degrees of polymerization, PS/PEB pairs give rise to higher upper critical solution temperatures than PS/PB pairs, indicating that PS/PEB pairs are less miscible than PS/PB pairs. Experimental phase diagrams were curve-fitted to theoretical phase diagrams predicted from the Flory−Huggins theory with the expression for the interaction parameter α:  α = a + b/T + cφPS/T, where α is related to the Flory−Huggins interaction parameter χ by χ = αV r, where V r is the molar reference volume, T is the absolute temperature, and φPS is the volume fraction of PS in the mixture. α values for PS/PB mixtures increase with increasing 1,2-addition (miscibility decreases) while α values for PS/PEB mixtures decrease (miscibility increases) with increasing 1-butene content. Using these α values, the Helfand−Wasserman theory was applied to predict the order−disorder transition temperatures of PS-block-PB and PS-block-PEB copolymers with varying 1,2-addition and 1-butene content, respectively.

Tailoring the morphology and swelling-shrinking behaviors of the conducting polymer hydrogels is vital to realizing enhanced performance. Here, we demonstrate an effective approach for the controlled growth of polypyrrole hydrogels with both electrical properties and hydrogel characteristics. Under the static synthetic conditions, the polypyrrole nanotubes are self-assembled to form mesoscale networks of the hydrogels. The effect of the kind and amount of the oxidants on the morphology and swellingshrinking behaviors of the polypyrrole hydrogels is investigated in detail. The strength of polypyrrole hydrogel is enhanced with the increase of the amount of the oxidant. In the case of Fe(NO 3 ) 3 as the oxidant, the swelling-shrinking properties of the polypyrrole hydrogels are improved due to the more polypyrrole granules as a mesoscale cross-linker on the surface of polypyrrole nanotubes.

Surface-initiated atom transfer radical polymerization (ATRP) was used to tailor the functionality of polysulfone (PSF) membranes. A simple one-step method for the chloromethylation of PSF under mild conditions was used to introduce surface benzyl chloride groups as active ATRP initiators. Covalently tethered hydrophilic polymer brushes of poly(ethylene glycol)monomethacrylate and 2-hydroxyethyl methacrylate and their block copolymer brushes were prepared via surface-initiated ATRP from the chloromethylated PSF surfaces. A kinetic study revealed that the chain growth from the membranes was consistent with a controlled process. X-ray photoelectron spectroscopy was used to characterize the surface-modified membrane after each modification stage. Protein adsorption experiments revealed substantial antifouling properties of the grafted PSF membranes in comparison with the those of the pristine PSF surface.

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Electrochemical copolymerization of pyrrole and indole was performed galvanostatically in a solvent of acetonitrile (AN)/water (vol %: 99/1). The product obtained was characterized by cyclic voltammetry and infrared spectroscopy. The influence of the monomer feed ratio of pyrrole and indole on the synthesis of the copolymer was investigated. The amount of pyrrole units in the copolymer chain increased with increase of the concentration of the pyrrole monomer in the solution. The results showed that the electrochemical activity of the copolymer was improved as the incorporation of pyrrole units increased. Thermogravimetric analysis was carried out to investigate the properties of the copolymer.