Polymer Journal
Vol. 37, No. 4 (April, 2005)


[Regular Article] Web Release Date: April 15, 2005
239-245 Fine Dispersion and Property Differentiation of Nanoscale Silicate Platelets and Spheres in Epoxy Nanocomposites
 C.-C. Chu, J.-J. Lin, C.-R. Shiu, and C.-C. Kwan
[Full Text PDF(J-STAGE)]
 The TEM micrograph shows a silicate platelet stack in a bilayer orientation, occurred in epoxy matrix. The stacking of one lamella over another extends up to 500 nm in length, observed here from the side view. The unique lamellar stacking is attributed to high aspect-ratio and ionic character of the exfoliated clay platelets.

[Regular Article] Web Release Date: April 15, 2005
246-254 Synthesis and Photochemical Reaction of Poly(ester)s Containing Donor–Acceptor Type Norbornadiene Residues in the Both Main and Side Chains
 Y. Ono, N. Kawashima, H. Kudo, T. Nagai, and T. Nishikubo
[Full Text PDF(J-STAGE)]
New polyesters containing donor–acceptor type Norbornadiene moieties in the both main and side chains were synthesized by the polyaddition of 5-(4-methoxyphenyl)-1,4,6,7,7-pentamethyl-2,5-norbornadiene-2,3-dicarboxylic acid diglycidyl ester (D–A NDGE) with terephthaloyl chloride follows by substitution reactions of the resulting polymer with potassium 5-(4-methoxyphenyl)-1,4,6,7,7-pentamethyl-3-methylester-2,5-NBD-2-carboxylate, potassium 5-(4-methoxyphenyl)-1,4,6,7,7-pentamethyl-3-(N,N-dipropylcarbamoyl)-2,5-NBD-2-carboxylate, and potassium 5-(4-methoxyphenyl)-1,4,6,7,7-pentamethyl-3-(N-methyl-N-phenylcarbamoyl)-2,5-NBD-2-carboxylate using TBAB as a phase-transfer catalyst in NMP, respectively. Then, we examined the photochemical isomerization and thermal energy storage property of the resulting polymers, and it was found that these polymers have very high photochemical reactivity and excellent stored thermal energy.

[Regular Article] Web Release Date: April 15, 2005
255-261 Structure, Solution Aggregation and UV Curing of Hyperbranched Poly(ester-amine)s with Terminal Acrylate Groups
 L.-M. Tang, Y. Fang, and J. Feng
[Full Text PDF(J-STAGE)]
 Hyperbranched poly(ester-amine)s with terminal acrylate groups synthesized from piperazine and trimethylolpropanetriacrylate formed aggregates in acetone–acidic water selective solution. Smaller aggregate size was obtained for the polymer with higher Mn, while the size distribution changed in accordance with Mw/Mn. Cured particles with decreased size were obtained through radiating the dispersion by UV light.

[Regular Article] Web Release Date: April 15, 2005
262-269 Ring Opening Polymerization of Oxetane by Use of Silicate Gel of Rare Earth Metal
 O. Moriya, S. Yamamoto, T. Sugizaki, J. Maeda, A. Kamejima, T. Kumon, and T. Kageyama
[Full Text PDF(J-STAGE)]
The gels of the rare earth metal silicate such as yttrium, neodymium, or samarium were found to be the effective solid catalysts for the ring opening polymerization of oxetane. The ring opening polymerization of oxetane proceeded readily at 20 °C in the presence of a catalytic amount of the silicate gels, in which the content of the rare earth metal was 10 mol % to oxetane. The silicate gel of yttrium was the most effective solid acid among those of the rare earth metals employed in this work.

[Regular Article] Web Release Date: April 15, 2005
270-276 New Negative-type Photosensitive Alkaline-developable Semi-aromatic Polyimides with Low Dielectric Constants Based on Poly(amic acid) from Aromatic Diamine Containing Adamantyl Units and Alicyclic Dianhydrides, A Cross-linker, and A Photoacid Generator
 Y. Watanabe, Y. Shibasaki, S. Ando, and M. Ueda
[Full Text PDF(J-STAGE)]
 A new negative-working and alkaline-developable photosensitive polyimide precursor based on semi-aromatic poly(amic acid)s, 4,4'-methylenebis[2,6-bis(hydroxymethyl)]phenol (MBHP) as a cross-linker, and a photoacid generator (5-propylsulfonyloxyimino-5H-thiophen-2-ylidene)-2-(methylphenyl)acetonitrile (PTMA) has been developed. The dielectric constants (ε) of the corresponding polyimides estimated from the refractive indices were 2.72–2.74. The photosensitive polyimide precursor containing poly(amic acid)s (60 wt %), MBHP (30 wt %), and PTMA (10 wt %) showed a clear negative image featuring 15 μm line and space patterns by exposure of 436 nm light.

[Regular Article] Web Release Date: April 15, 2005
277-283 Cholesteric Liquid-Crystalline Elastomers Prepared from Ionic Bis–Olefinic Crosslinking Units
 F.-B. Meng, B.-Y. Zhang, Q.-Y. Li, and J. Qi
[Full Text PDF(J-STAGE)]
 A series of cyclosiloxane-besed cholesteric LCEs were synthesized by using a LC monomer and an ionic divinyl monomer with ionic crosslinking contents ranging from 0 to 11.8%. With increase of ionic crosslinking component in the polymers, the melting behavior disappears and the temperature of clear point decreases. Reflection spectra of cholesteric mesophase of the polymers showed that the reflected wavelength becomes broad and shifts to long wavelengh with increase of the ionic crosslinking component in the polymer systems.

[Regular Article] Web Release Date: April 15, 2005
284-293 Synthesis of Dendritic, Non-Kekulé-, and Nondisjoint-type Triphenylmethanes Terminated with Galvinoxyl Radicals
 E. Fukuzaki, N. Takahashi, S. Imai, H. Nishide, and A. Rajca
[Full Text PDF(J-STAGE)]
 A series of triphenylmethanes terminated with (a) hydrogalvinoxyl(s), bis(4-tert-butylphenyl)-(4-hydrogalvinoxylphenyl)methoxymethane, tris(4-hydrogalvinoxylphenyl)methoxymethane, and tris{4-[bis(4-hydrogalvinoxylphenyl)methoxymethyl]phenyl}methoxymethane, were synthesized. The hydrogalvinoxyl combined triphenylmethane was converted to the corresponding biradical with a multiplet state.

[Regular Article] Web Release Date: April 15, 2005
294-298 Solvent Effect on Junction Size in Syndiotactic Polystyrene Physical Gel
 H. Shimizu, T. Wakayama, R. Wada, M. Okabe, and F. Tanaka
[Full Text PDF(J-STAGE)]
 The crystalline junction size ζ of sPS gels was estimated with the aid of the Tanaka and Stockmayer theory, which is based upon the conjecture that junction points of a gel are aggregates comprised of ζ units in length and ρ sequences in cross section. The junction size ζ was little affected by the sPS molecular weight. On the other hand, the size ζ in sPS gels was strongly dependent on the gelation solvent. This solvent effect on the junction size ζ probably arises from the difference in magnitude of polymer/solvent interaction.

[Regular Article] Web Release Date: April 15, 2005
299-308 Synthesis, Chiroptical Properties, and Chiral Recognition Ability of Optically Active Polymethacrylamides Having Various Tacticities
 K. Morioka, Y. Isobe, S. Habaue, and Y. Okamoto
[Full Text PDF(J-STAGE)]
The radical polymerization of optically active methacrylamides was carried out under various conditions using a Lewis acids, ytterbium trifluoromethanesulfonate (Yb(OTf)3). Although syndiotactic polymers were obtained by a normal radical method, isotactic-rich polymers were obtained in the presence of the Lewis acid. The specific rotations and circular dichroism spectral patterns of the obtained polymers varied with tacticities. The polymethacrylamides having different tacticities were immobilized on silica gel and used as the CSPs for HPLC resolution of the various racemates.

[Regular Article] Web Release Date: April 15, 2005
309-315 Study of a Naturally Drying Lacquer Hybridized with Organic Silane
 R. Lu, T. Honda, T. Ishimura, and T. Miyakoshi
[Full Text PDF(J-STAGE)]
 A natural drying lacquer hybridized with organic silane has been developed in this study. The hydroxyl group of urushiol contained in the lacquer sap underwent alcoholysis reaction with organic silane and generated polysiloxane. The amino residues in organic silane react with the cathechol ring of urushiol, and then the hybrid oxidizes to a dark color.

[Regular Article] Web Release Date: April 15, 2005
316-323 Analysis of Compositional Drift in Methyl Methacrylate and n-Butyl Acrylate Copolymers Synthesized by Atom Transfer Radical Polymerization Using 13C{1H} NMR Spectroscopy
 A. S. Brar and S. Kaur
[Full Text PDF(J-STAGE)]
 Compositional variations occurring along the chains in the copolymers of methyl methacrylate and n-butyl acrylate synthesized using Atom Transfer Radical Polymerization were investigated using 13C{1H} NMR spectroscopy. Copolymer compositions were calculated from 1H NMR spectra. Analysis of the variations of β methylene dyads and M- and B-centered triad fractions with conversion was done using DEPT experiments to study the trend followed by compositional drift which showed the uniformity occurring along the copolymer chains leading to formation of gradient copolymers.

[Regular Article] Web Release Date: April 15, 2005
324-331 Small-Angle X-Ray Scattering from Polystyrene Polymacromonomers in Cyclohexane
 K. Amitani, K. Terao, Y. Nakamura, and T. Norisuye
[Full Text PDF(J-STAGE)]
 Small-angle X-ray scattering (SAXS) measurements have been made on 7 polystyrene polymacromonomer samples with a fixed side chain length of 15 styrene residues in cyclohexane at the theta temperature. It is shown that the molecular weight dependence of radius of gyration and the angular dependence of scattering function are explained by the cylindrical wormlike chain with the model parameters consistent with previous light scattering radii, intrinsic viscosities, and translational diffusion coefficients in the same solvent.