Polymer Journal
Vol. 37, No. 6 (June, 2005)

[Regular Article] Web Release Date: June 15, 2005

391-398 Preparation of Polysaccharide Nanofiber Fabrics by Electrospray Deposition: Additive Effects of Poly(ethylene oxide)  H. Seo, H. Matsumoto, S. Hara, M. Minagawa, A. Tanioka, H. Yako, Y. Yamagata, and K. Inoue [Full Text PDF(J-STAGE)]

Polysaccharide—chitosan, sodium chondroitin sulfate, and pectin—nanofibrous fabrics were prepared from the respective polysaccharide/poly(ethylene oxide) (PEO) blend solutions by electrospray deposition (ESD). Unblended polysaccharide solutions showed low ESD processability. The addition of high-molecular-weight PEO (Mw=500,000) to chitosan solutions significantly enhanced the formation of a fibrous structure. Sodium chondroitin sulfate/PEO and pectin/PEO blend solutions were generally too viscous to be sprayed at 25 °C; at 70 °C, however, we succeeded in forming the fibrous structure from these solutions by ESD.

[Regular Article] Web Release Date: June 15, 2005

399-403 Preparation and Characterization of Fluorine-containing Aromatic Condensation Polymers VIII. Aromatic Polyether and Copolyethers from 2,2-Bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-Bis(4-hydroxyphenyl)propane, or both and Bis(4-fluorophenyl)phenylphosphine Oxide  Y. Saegusa and T. Koizumi [Full Text PDF(J-STAGE)]

A series of hexafluoroisopropylidene group-containing aromatic polyether and copolyethers with a wide range of unit ratios were synthesized from bisphenols 1a, 1b, or both and activated difluoride 2, and the effect of fluorine substitution on the properties of these polymers is discussed in relation to the fluorine contents. Regardless of the fluorine contents, these polymers all were soluble in various organic solvents and afforded colorless, transparent, and tough films by solution casting. The contact angles of the films to water and the Tg's increased monotonously with increasing fluorine content. 1a-based homopolyether had the lowest dielectric constant of 2.79.

[Regular Article] Web Release Date: June 15, 2005

404-412 Helix–Coil Transition and Micellar Structure of Poly(ethylene glycol)-block-Poly[N5-(2-hydroxyethyl) l-glutamine] in Cyclohexanol/Water Mixed Solvents  K. Inomata, M. Itoh, and E. Nakanishi [Full Text PDF(J-STAGE)]

Structure analysis of associated micelles formed by polypeptide-based diblock copolymer, poly(ethylene glycol)-block-poly[N5-(2-hydroxyethyl) l-glutamine] (PEG-b-PHEG), in dilute solution has been investigated. Cyclohexanol/water mixed solvent was used as selective solvent, in which PHEG forms associated domains. With increase of the water content, helix content of PHEG decreased and structure of the micelle was supposed to change from vesicle-like hollow cylinder to core-corona type cylinder. The obtained results indicate that the conformation and packing manner of the associated core-forming block strongly influence the structure of diblock copolymer micelles.

[Regular Article] Web Release Date: June 15, 2005

413-417 Gas Permeability of Thermoplastic Polyurethane Elastomers  K. Matsunaga, K. Sato, M. Tajima, and Y. Yoshida [Full Text PDF(J-STAGE)]

We have studied the influence of the chemical structures of thermoplastic polyurethane elastomers on their permeability to carbon dioxide and oxygen. Those contents are as the following. (1) The influence of chemical structure of soft segments on gas permeability. (2) The temperature dependences of gas permeability. (3) The influence of the soft-segment chain length on gas permeability. (4) The influence of the chemical structure of the hard segment on gas permeability.

[Regular Article] Web Release Date: June 15, 2005

418-428 Non-isothermal Crystallization of Poly(ethylene-co-glycidyl methacrylate)/Silica Nanocomposites  J.-W. Huang, C.-C. Kang, C.-J. Lin, and C.-T. Lee [Full Text PDF(J-STAGE)]

Three crystallization kinetic models proposed respectively by Avrami, Ozawa, and Liu successfully described the non-isothermal crystallization processes of neat PEGMA, PEGMA/Silica, and PEGMA/A-Silica. All models predicted correctly that the crystallization rate followed the order: PEGMA/Silica > PEGMA/A-Silica > PEGMA. Among the three models, Avrami model provided a simple method to describe a nonisothermal crystallization process although the physical meanings of its kinetic parameters are not yet clear.

[Regular Article] Web Release Date: June 15, 2005

429-433 Melting Behavior of Bound Solvent in Isotactic Polypropylene/o-Dichlorobenzene Gel  T. Nakaoki and S. Harada [Full Text PDF(J-STAGE)]

Thermal analysis of o-dichlorobenzene in isotactic polypropylene/o-dichlorobenzene gel provided two endothermic peaks. One is very broad and strongly dependent on polymer concentration. The other is close to the melting of pure o-dichlorobenzene but slightly broadened. The existence of two bound solvents in the gel was confirmed, one loosely bound in the gel and the other bound more firmly by the polymer. In polarized micrograph, the maltese cross was observed in the gel, indicating the formation of spherulite. It was suggested that the morphology of polymer chain is closely related to the melting behavior of solvent.

[Regular Article] Web Release Date: June 15, 2005

434-438 Core/Shell and Hollow Polymeric Capsules Prepared from Calcium Carbonate Whisker  T. Sasaki, T. Kitagawa, S. Sato, S. Irie, and K. Sakurai [Full Text PDF(J-STAGE)]

Polymeric capsules of a rod-like shape were prepared by depositing a poly(methyl methacrylate) or polystyrene thin layer onto the surface of calcium carbonate whisker via emulsion polymerization. The obtained core/shell capsules were also converted to hollow capsules by dissolving the core material in a hydrochloric acid solution. The average thickness of the outer shell ranged from 29 to 72 nm. The glass transition temperatures of the outer shell were almost identical to those of the bulk both for the core/shell and hollow capsules.

[Regular Article] Web Release Date: June 15, 2005

439-448 Structural Analyses of Methyl Bicyclobutane-1-carboxylate Oligomers Formed with tert-Butyllithium/Aluminum Bisphenoxide and Mechanistic Aspect of the Polymerization  T. Kawauchi, M. Nakamura, T. Kitayama, A. B. Padias, and H. K. Hall, Jr. [Full Text PDF(J-STAGE)]

Anionic polymerization of methyl bicyclobutane-1-carboxylate (MBCB) with t-BuLi/bis(2,6-di-tert-butylphenoxy)ethylaluminum [EtAl(ODBP)2] in toluene at -78 °C gave transtactic polymers (trans contents > 90%) with high yields, but with low initiator efficiency and broad molecular weight distribution. In order to obtain information on the initiation mechanism, oligomers of MBCB were prepared with t-BuLi/EtAl(ODBP)2 in toluene at -78 °C, and fractionated into the dimer to pentamer by SEC. The dimer fraction was further subjected to recycling SEC and found to consist of two types of dimers of different chemical structures. 1H NMR analyses of the dimers revealed that one type of the dimer comprises of the initiating t-Bu group and two MBCB units while the other contains one t-Bu carbonyl group within the monomeric unit in addition to the initial t-Bu group. The results indicate that the carbonyl addition of t-BuLi to MBCB occurred and the ketonic compound thus formed participates in the polymerization.

[Note] Web Release Date: June 15, 2005

449-452 New Optically Active Poly(amide–imide)s Containing N-Trimellitylimido-l-phenylalanine and Hydantoin Moieties: Synthesis and Properties  K. Faghihi [Full Text PDF(J-STAGE)]

The direct polycondensation reaction of N-trimellitylimido-l-phenylalanine (3) with hydantoin (4a), 5,5-dimethyl hydantoin (4b), 5-ethyl-5-methylhydantoin (4c), 5,5-diethylhydantoin (4d), 5-spirocyclopentylhydantoin (4e) and 5-spirocyclohexylhydantoin (4f) was carried out in a medium consisting of triphenyl phosphite, N-methyl-2-pyrrolidone, pyridine and calcium chloride. These polymers were obtained in high yields and have inherent viscosities between 0.53–0.62 dL/g.