Polymer Journal
Vol. 38, No. 8 (August, 2006)

[Award Accounts: SPSJ Wiley Award (2005)] Web Release Date: July 24, 2006

743-756 π-Electronic Soft Materials Based on Graphitic Nanostructures  T. Fukushima [Full Text PDF(J-STAGE)]

This paper reviews our recent studies on π-electronic soft materials consisting of graphitic nanostructures. We disclosed novel composite materials consisting of carbon nanotubes and ionic liquids. By programmed self-assembly of graphene-like molecules, we developed non-covalent graphitic nanotubes with tailored electronic functions. One-dimensional columnar assemblies formed from such molecular graphenes can be constructed in the channels of mesoporous silicates. Herein, details of the design, properties, and scope of our materials are described.

[Regular Article] Web Release Date: June 30, 2006

757-766 Application of Catastrophe Theory to the Neck-initiation of Semicrystalline Polymers Induced by the Intercluster Links  K. Nitta and M. Takayanagi [Full Text PDF(J-STAGE)]

The necking initiation in semi-crystalline polymers composed of lamellar clusters can be explained by catastrophic phase-transition in the same manner of a first order phase transition of van der Waals gas. Catastrophic arrangement of the intercrystalline links results in sudden emergence of the locally oriented region, leading to the neck formation.

[Regular Article] Web Release Date: June 30, 2006

767-780 The Effect of Rubber Type and Rubber Functionality on the Morphological and Mechanical Properties of Rubber-toughened Polyamide 6/Polypropylene Nanocomposites  M. U. Wahit, A. Hassan, Z. A. Mohd Ishak, A. R. Rahmat, and N. Othman [Full Text PDF(J-STAGE)]

The effect of rubber type and functionality on the morphological and mechanical properties of rubber-toughened polyamide 6/polypropylene nanocomposites containing organophilic modified montmorilonite (OMMT) was investigated in term of mechanical testing, X-ray diffraction (XRD) and scanning electron microscopy (SEM) Malaysianhungary Bilateral Program. The toughness of the nanocomposites toughened by maleated elastomer was higher than the unmaleated elastomer. The SEM observation revealed that rubber functionality reduces the elastomer particle size in the PA6/PP matrix due to the in situ formation of graft copolymer between maleated elastomer and PA6.

[Regular Article] Web Release Date: June 30, 2006

781-785 Significant Effect of Dopant Size on Nanoscale Fractal Structure of Polypyrrole Film  A. Eftekhari, M. Kazemzad, and M. Keyanpour-Rad [Full Text PDF(J-STAGE)]

Surface morphologies of thin films of polypyrrole doped with two similar anions (with different ionic radii) viz. chloride and bromide were compared by means of fractal geometry. Scanning electron micrographs of the polymer surfaces showed a significant difference between the surface structures of two anion-doped polypyrrole films in microscale and particularly in nanoscale. Surprisingly, the bromide-doped polypyrrole had nanostructure; whereas, the chloride-doped polypyrrole surface was smooth in nanoscale. An electrochemical method based on gold-masking approach was employed to reveal the fractality of these polymer surfaces in microscale.

[Regular Article] Web Release Date: June 30, 2006

786-798 Size Shrinkage of Methacrylate-based Terpolymer Latexes Synthesized by Free Radical Polymerization: Kinetics and Influence of Main Reaction Parameters  S. Armini, C. M. Whelan, M. Smet, S. Eslava, and K. Maex [Full Text PDF(J-STAGE)]

Monodisperse PMMA-based terpolymer particles are synthesized with a wide and controllable range of size and polymer content by emulsifier-free free radical emulsion polymerization. The effect of monomer amount, reaction temperature and initiator concentration is investigated. A kinetic study of the evolution of the terpolymer colloid composition and morphology reveals a mechanism of fast homogeneous nucleation. The composition of the particles changes continuously during the polymerization, giving rise to a spectrum of polymer properties promising for a number of unique applications.

[Regular Article] Web Release Date: July 7, 2006

799-806 Effect of Soft Segments of Waterborne Polyurethane on Organic Vapor Sensitivity of Carbon Black Filled Waterborne Polyurethane Composites  B. Zhao, R. W. Fu, M. Q. Zhang, H. Yang, M. Z. Rong, and Q. Zheng [Full Text PDF(J-STAGE)]

Three types of waterborne polyurethane (WPU) with different soft segments were synthesized. The WPUs were then compounded with carbon black to fabricate gas sensing composites. By studying the composites’ resistance variation in different solvent-vapors, it was found that the structures of the WPUs remarkably affected the composites’ response behaviors. Both polarity and flexibility of the soft segments of WPU determine the solvent-polymer interaction and preferential localization of solvent and fillers, resulting in different magnitudes of resistance increase and rates of response.

[Regular Article] Web Release Date: July 7, 2006

807-813 Polymer Grafting onto Carbon Black by Solid State Method  H. Xu, B. Li, and C. Wu [Full Text PDF(J-STAGE)]

In situ grafting of natural rubber (NR) onto the CB surface by solid state method was investigated in this paper. The torque value of CB/NR blend system in Haake internal mixer and FT IR spectra of grafted carbon black (GCB) illuminated that the grafting reaction took place. The orthogonal design (ORD) showed that the degradation time of NR and mixing temperature played an important role in the grafting process. The mechanical properties of vulcanized NR filled with GCB were enhanced to a large extent.

[Regular Article] Web Release Date: July 7, 2006

814-818 Physical Aging and Refractive Index of Poly(methyl methacrylate) Glass  N. Tanio and T. Nakanishi [Full Text PDF(J-STAGE)]

Physical aging of poly(methyl methacrylate) (PMMA) glass was studied by refractive index measurement. We measured change of refractive index of PMMA glass with annealing at temperatures below the glass transition temperature (Tg) by optical prism coupling, and determined volume relaxation by physical aging using the Lorentz-Lorenz equation. In this paper, the effect of aging temperature on volume relaxation of PMMA glass was investigated. Maximum volume relaxation for PMMA glass was determined at 20 °C below the Tg.

[Regular Article] Web Release Date: July 7, 2006

819-826 Two Different Surface Properties of Regenerated Cellulose due to Structural Anisotropy  C. Yamane, T. Aoyagi, M. Ago, K. Sato, K. Okajima, and T. Takahashi [Full Text PDF(J-STAGE)]

High planar orientation index f(1-10) and high crystallinity Xc values yielded significantly lower contact angles. Water contact angle of ca. 12° is far lower than that of widely used polymers. Because of the density of hydroxyl groups on the (1-10) surface is very high, higher Xc and f(1-10) values resulting in a larger surface area fraction of (1-10) planes in regenerated cellulose films produce the most hydrophilic polymer, more wettable than PVA and starch.

[Regular Article] Web Release Date: July 14, 2006

827-834 Positive-type Alkaline Developable Photosensitive Branched Polyamides with Low Degree of Branching and Diazonaphthoquinone as a Photosensitive Compound  J. Xiao, Y. Inai, L. Li, T. Hayakawa, and M. Kakimoto [Full Text PDF(J-STAGE)]

A positive-type photosensitive polyamide based on the branched polyamides with low degree of branching (DB) and diazonaphthoquinone (S-DNQ) as a photosensitive compound has been developed. The branched polyamides with low DB having phenolic hydroxy end groups were prepared by through polycondensation of ABB′ type monomer and subsequently end-modification of the branched polyamides having amino end groups obtained. A fine positive image of 6 μm line-and-space pattern was obtained when the film was exposed to 300 mJ cm−2 by contact-printing mode.

[Regular Article] Web Release Date: July 14, 2006

835-843 In Situ Polymerization and Properties of Methyl Methacrylate-Butadiene-Styrene Resin with Bimodal Rubber Particle Size Distribution  J. Takahashi, H. Watanabe, J. Nakamoto, K. Arakawa, and M. Todo [Full Text PDF(J-STAGE)]

In situ polymerization and mechanical properties of rubber-modified MBS resin with a bimodal rubber particle size distribution were investigated. Rubber-modified MBS resin was prepared by bulk-suspension polymerization. Bimodal rubber particle size distribution was observed during bulk polymerization. Size distribution was regulated by the viscosity of prepolymer or shearing. MBS resin with bimodal distribution (Sample code D-2) was superior in balance of impact resistance and transparency.

[Regular Article] Web Release Date: July 14, 2006

844-851 Preparation of Antibacterial Polymer-grafted Nano-sized Silica and Surface Properties of Silicone Rubber Filled with the Silica  R. Yamashita, Y. Takeuchi, H. Kikuchi, K. Shirai, T. Yamauchi, and N. Tsubokawa [Full Text PDF(J-STAGE)]

The grafting of polymeric phosphonium salt, poly(St-SO3−P+Bu3R), onto the silica surface was achieved by the treatment of poly(p-styrene sodium sulfate) [poly(St-SO3−Na+)] with tributyltetradecylphosphonium chloride (Bu3RP+Cl−). The poly(St-SO3−P+Bu3R)-grafted silica gave a stable dispersion in DMSO and poly(dimethylsiloxane). It was found that silicone rubber filled with the poly(St-SO3−P+Bu3R)-grafted silica shows extremely strong antibacterial activity. The silicone rubber surface has an ability to inhibit the reproduction of a Staphylococcus aureus and an Escherichia coli.

[Regular Article] Web Release Date: July 14, 2006

852-860 Synthesis of Star-shaped 8 arms Poly(ethylene glycol)-Poly(L-lactide) Block Copolymer and Physicochemical Properties of Its Solution Cast Film as Soft Biomaterial  K. Nagahama, Y. Ohya, and T. Ouchi [Full Text PDF(J-STAGE)]

Star-shaped 8 arms PEG-b-PLLA was synthesized to create the novel implantable soft material. The 8 arms PEG-b-PLLA films showed drastically lower crystallinity of PLLA compared with the corresponding linear 2 arms PEG-b-PLLA film. The homogeneously fine PLLA domains were formed in the 8 arms PEG-b-PLLA film, whereas the miscellaneous PLLA domains were formed in the 2 arms PEG-b-PLLA film. Consequently, the 8 arms PEG-b-PLLA film showed higher water absorption ability and lower tensile strength as well as higher elongation at break than the 2 arms PEG-b-PLLA film.

[Regular Article] Web Release Date: July 24, 2006

861-867 Electrostatic Contributions to Chain Stiffness and Excluded-Volume Effects in Sodium Poly(2-acrylamido-2-methylpropanesulfonate) Solutions  R. Hagino, J. Yashiro, M. Sakata, and T. Norisuye [Full Text PDF(J-STAGE)]

The electrostatic persistence length qel and the excluded-volume strength B for Na poly(2-acrylamido-2-methylpropanesulfonate) in aqueous NaCl at 25 °C are estimated as functions of salt concentration Cs by analysis of intrinsic viscosity data based on the wormlike chain with excluded volume. It is shown that, as was the case for Na poly(styrenesulfonate), available polyelectrolyte theories fail to describe the Cs-dependence of the estimated qel and B.

[Regular Article] Web Release Date: July 24, 2006

868-875 Morphology of Segmented Polyether Based Poly(urea-urethane) Thermoplastic Elastomers  J.-Y. Liu, Y.-C. Hsu, and Y.-Z. Wang [Full Text PDF(J-STAGE)]

A series of aniline-containing segmented poly(urea-urethane) were prepared as a conductive material. An amine-terminated functional group was introduced into the poly(urea-urethane) as a chain extender to form the hard segment of the copolymer. The conductivity of copolymers is found to be ranged from 0.83S/cm for the neat OPA to 1.96× 10−6S/cm for the resultant copolymers. TEM and CP experiments results indicate that morphology of conducting copolymers undergo microphase separation and the domain size is on a nanophase scale.