Polymer Journal
Vol. 37, No. 5 (May, 2005)

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

333-339 A New Trend in Radiation Vulcanization of Natural Rubber Latex with a Low Energy Electron Beam  MD. E. Haque, K. Makuuchi, H. Mitomo, F. Yoshii and K. Ikeda [Full Text PDF(J-STAGE)]

The natural rubber latex was radiation vulcanized under low energy electron accelerator in a reaction vessel with constant stirring. The parameters such as defoamer concentration, irradiation time, volume of latex, beam current, latex conc. etc. were optimized. Maximum tensile strength of ∼26 MPa of the irradiated rubber is obtained with 5 phr nonane-diol-diacrylate or normal butyl acrylate used as radiation vulcanization accelerator (RVA). Twenty minutes irradiation time is needed to vulcanize 14 L of latex when 5 phr RVA is used.

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

340-349 Properties of Poly(vinyl chloride) Modified by Cellulose  H. Kaczmarek, K. Bajer, and A. Podgórski [Full Text PDF(J-STAGE)]

Compositions of poly(vinyl chloride) with 2–10 (w/w) cellulose were composted in garden soil up to 14 months. The biodegradation was monitored by weight loss, ATR-FT IR spectroscopy and mechanical property measurements. Thermal stability of virgin and composted samples was studied by thermogravimetry. Moreover, water absorptiveness of all samples was estimated.

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

350-354 Effect of Quaternary Cations on the Electrochemical Synthesis of Polyaniline and Its Degradation  L. Sun, H. C. Zhang, C. M. Jiang, Q. R. Li, and R. K. Bai [Full Text PDF(J-STAGE)]

The effect of quaternary cations on the electrochemical degradation of PANI was researched. The result showed that the cations hindered gradually the polymerization of aniline with increase of the size, which made the porosity of the film smaller and the morphology more compact compared with pure PANI film. Although the cations didn't change the electrode reactive process of PANI, they affected the oxidation velocity and the degradation rate of PANI film in the following order: Bu4N+ > Et4N+ > Me4N+. The stability of the films was enhanced.

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

355-362 Synthesis and Characterization of Polybinaphthyls Incorporating Chiral (R) or (S)-2,2'-Binaphthyl Entities by Heck Reaction  Y. Cheng, L. Chen, J. Song, X. Zou, and T. Liu [Full Text PDF(J-STAGE)]

Four chiral conjugated polymers P-1, P-2, P-3 and P-4 were obtained by the polymerization of (R) or (S)-2,2'-binaphthyl with the two divinyl conjugated monomers under Pd-catalyzed Heck reaction. The butoxy substitutents on the phenyl and binaphthyl rings as side chain of the polymers can improve solubility in organic solvents. Four chiral polymers containing vinylene linkages between naphthyl and phenyl groups can reduce steric hindrance between backbone rings and groups, and also have a beneficial effect on delocalizable π-electronic conjugation structure of polymers.

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

363-367 Application of a New Cell Model for the Equation of State to 20 Polymer Melts and a Blend Melt  M. Murakami [Full Text PDF(J-STAGE)]

We apply a new cell model for the equation of state to 20 polymer melts and a blend melt. The linear lengths of the coarse-grained particle (CGP) of several polymers coincide with those obtained by scattering experiments. In addition, we estimated the characteristic quantity T* of the equation of state per repeating unit using van der Waals constants and the critical temperature of the repeating unit or monomer. The values, T*, agreed with those from our result per repeating unit.

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

368-375 Effects of Hydrophobic Chain Length on the Micelles of Heptaoxyethylene Hexadecyl C16E7 and Octadecyl C18E7 Ethers  Y. Einaga, A. Kusumoto, and A. Noda [Full Text PDF(J-STAGE)]

The weight-average micellar length Lw of the C18E7 micelles (unfilled circles) increases with concentration c to much greater extent than that of the C16E7 micelles (filled circles) when compared at the same temperature T.

[Note] Web Release Date: May 15, 2005

376-379 Fibers from Multi-walled Carbon Nanotube/Polyacrylonitrile Composites  B. Wang, H. Wang, B. Hong, and Y. Zhang [Full Text PDF(J-STAGE)]

Considerable improvement in the dispersion of multi-walled carbon nanotubes (MWNTs) in polyacrylonitrile (PAN) matrix was attained through Gum Arabic treatment and in-situ polymerization. Fibers from these MWNT/PAN composites were prepared by traditional wet-spinning process. The storage modulus of MWNT/PAN composite fibers increased with nanotube loading, and the percolation threshold of electrical conductivity for these composite fibers was ∼0.5 wt % nanotube loading.

[Note] Web Release Date: May 15, 2005

380-383 Efficient Cobalt Complex on the Reaction between Isophorone Diisocyanate and Diethylene Glycol  S. Inoue and Y. Nagai [Full Text PDF(J-STAGE)]

The reactions catalyzed by metal–β-diketone complexes (Mt(acac)n) and Co(f6acac)2–Co(acac)2 complex between isophorone diisocyanate (IPDI) and diethylene glycol (DEG) in DMF are studied. It is clear thet Co(f6acac)2–Co(acac)2 complex show more activity than that of DBTDL, and the resulting product, polyurethane elastomer is colorless. From a kinetic study, the rate constant (k) at 30 °C is expressed by k = k0+Kc[Co(f6acac)2–Co(acac)2]0.86. The overall activation energy on the reaction between IPDI and DEG is 67.6 kJ/mol. The activity of this catalyst is comparable to that of dibutyltin dilaurate.

Web Release Date: May 15, 2005

384-390 Synthesis of New Hydroxy-bearing Polyurethanes: Polyaddition of d-Glucose-derived Diols with Diisocyanates  K. Hashimoto, K. Yaginuma, S. Nara, and H. Okawa [Full Text PDF(J-STAGE)]

New polyurethanes bearing hydroxy groups (9 and 10) were synthesized almost quantitatively by the polyaddition of two kinds of d-glucose-derived diols [methyl 4,6-O-benzylidene-α-d-glucopyranoside (4) and 1,2:5,6-di-O-isopropylidene-d-glucitol (5)] with hexamethylene diisocyanate (6a) and methyl (S)-2,6-diisocyanatohexanoate (lysine diisocyanate, 6b) in N,N-dimethylformamide at 25 or 50 °C and their subsequent deprotection in trifluoroacetic acid aqueous solution. Their thermal degradation was found to begin at lower temperature than that of the original protected polyurethanes (7 and 8).