Volume 43 Issue 3, March 2011

The solubility and phase behavior of five polyethers in 14 different room-temperature ionic liquids (ILs) were studied by changing the structures of polyethers and the cations and anions in the ILs. Certain combinations of a polyether and an IL binary mixture exhibited lower critical solution temperature (LCST) phase behavior. The phase separation temperature (cloud point) was revealed to be sensitive to the aromaticity and alkyl chain length of the IL cations, the anionic Lewis basicities of the ILs and the polarity of the polyethers. PEGE, poly(ethyl glycidyl ether).

The SiO₂–TiO₂ hybrid nanoparticle was prepared by the sol-gel process in polyamic acid solution for the synthesis of the polyimide (PI)/SiO₂–TiO₂ ternary hybrid nanocomposite. Complementing effects of SiO₂ and TiO₂ on the nanocomposite were observed, based on reduced particle size and enhanced thermal stability. A uniform dispersion of the SiO₂–TiO₂ nanoparticles in the PI matrix with particle size of 5–10 nm was obtained.

A new class of perfluorocyclobutyl poly(arylene ether)s containing 1H-1,2,3-triazoles rings were prepared. The polymer backbones and 1H-1,2,3-triazoles rings are connected by flexible oligo(ethylene oxide) side chains. The preparation process, structure and properties of these polymers of these polymers were investigated.

A new synthetic methodology has been carried out for functionalized polystyrene through acylation and grafting under microwave energy. Improves in the corrosion resistance of both products suggest a good capacity as protective coating.

Dehydration polycondensation of bromoadipic acid and methylsuccinic acid with 1,4-butanediol was performed at 80 °C to synthesize aliphatic polyesters containing pendent bromo groups without dehydrobromination using scandium trifluoromethanesulfonate as the catalyst. Azidation of poly(butylene bromoadipate-co-butylene methylsuccinate) also proceeded to generate poly(butylene azidoadipate-co-butylene methylsuccinate) (M_n=10.4 × 10³). We successively photo-crosslinked the resultant azidopolyesters by UV irradiation. We also described azidation of polyesters having pendent hydroxyl groups by using the ‘diphenylphosphoryl azide-1,8-diazabicyclo[5.4.0]undec-7-ene substitution strategy’ to produce water-soluble polyesters containing pendent azido groups (M_n=7.5 × 10³).

Asymmetric anionic homopolymerizations of (S)-(–)-N-maleoyl-L-leucine-aza-15-crown-5 ((S)-A15C5LMI) and (S)-(–)-N-maleoyl-L-phenylalanine-aza-15-crown-5 ((S)-A15C5PAMI) were carried out with chiral anionic initiator consisting of organometal and chiral ligand to obtain optically active polymers. Chiroptical properties and structures of the polymers obtained were analyzed by circular dichroism, ultraviolet, nuclear magnetic resonance and gel permeation chromatography measurements. The additional effects of (R)-cyclohexylethylamine (to the obtained poly((S)-A15C5LMI) were investigated.

The present paper focuses on the utilization of the combination of low molecular weight vulcanizing accelerator with clay minerals for creating new rubber material with enhanced performance and properties. Gradual expansion of the interlayer space of the clay minerals was carried out by disteraylammonium compound followed by bis(diisopropyl) thiophosphoryl disulfide. Therefore, such expanded clay minerals facilitate easier penetration of the macromolecular rubber chains into the interlayer space of the clay minerals.

A statistical mechanical theory on the effects of the denaturant molecule on the protein helix–coil transition is developed. The unfolding agents are assumed to attach to the polypeptide backbones and disturb the formation of the hydrogen bond. The polypeptide becomes denaturated by the following reaction: h (helix) ⇌c (random coil) ⇌c* (random coil attached by denaturant). The results obtained from the theory are compared with the experimental result of short oligopeptides.

This paper describes the preparation of size-controlled CdS nanoparticles in block copolymer micelles and the formation of composite particles of the CdS nanoparticles and polymers. Uniformly sized CdS nanoparticles having various color emission spectra were successfully synthesized. Moreover, composite Janus particles, unidirectionally stacked lamellae and onion particles were formed by combination of CdS nanoparticles and polymer blend or block copolymer systems. This approach provides a simple route for preparation of functional organic/inorganic composite particles.

We designed and synthesized a zero-photoelastic birefringence polymer that had a high glass-transition temperature (T_g) by introducing trans-stilbene units into the side chains of the copolymer by a random copolymerization method. The concentration of the trans-stilbene units required to compensate for photoelastic birefringence in the random copolymer was lower than that required in a polymer prepared by in anisotropic molecule dopant method, because the presence of an anisotropic moiety in the side chain of the polymer has a greater effect than does an anisotropic molecule doped in the polymer.

Novel procedure is proposed to recover noble metals by means of extraction of the metal ion from a dilute aqueous solution to chloroform solution containing polyleucine-block-polyethylene glycol (PEG)-blockpolyleucine followed by the separation of the chloroform gel phase induced by the thermosensitive sol-gel transition. A characteristic specificity of the peptide copolymer gel for Au ion was found and number of capture-sites per one copolymer chain and adsorption equilibrium constants between the capture-site and one Au ion were evaluated, and then the capturing mechanism was discussed.

The maximum radial growth rate of spherulites of the novel stereocomplexationable blend of poly(L-2-hydroxybutyrate) (P(L-2HB)) and poly(D-2-hydroxybutyrate) (P(D-2HB)) was observed to be substantially higher than those of pure P(L-2HB) and P(D-2HB). The hydrolytic/thermal degradation rate of the P(L-2HB)/P(D-2HB) blend was retarded as compared with those of pure P(L-2HB) and P(D-2HB). These results indicate that the intermolecular interaction between P(L-2HB) and P(D-2HB) chains having opposite configurations was higher than that between P(L-2HB) or P(D-2HB) chains with the same configurations and are very useful for designing novel P(L-2HB)/P(D-2HB) stereocomplex-based biodegradable materials.

Hyperbranched fluorinated polymers with different fluorine contents and comonomer structure were synthesized by A₂+B₃ polymerization of phenol derivatives (A2 monomer) and 1,1′,1′′-tris(4-glycidyloxyphenyl)methane (B₃ monomer). The n_D was affected by the monomer and polymer structures, and the fluorine content of hyperbranched polymers. Cured materials tended to increase n_D because of the increase of crosslinking density of the film.