Melt rheology of hyperbranched‐polystyrene synthesized with multisite macromonomer

Melt rheological behaviors of hyperbranched‐polystyrene (PS) copolymerized by dendric macromonomer technique are presented. The time–temperature superposition principle was applicable to the hyperbranched‐PS. The branched‐PS showed slightly lower zero‐shear viscosity in comparison with linear PS regardless of a presence of a number of branches expected from the dendric macromonomer technique. Although the influence of use of multimethacryloyl macromonomer in the polymerization process was marginal for linear viscoelastic regime, nonlinear shear and uniaxial elongational flows showed distinct differences between linear and branched‐PS. The strain dependence of the damping function became weak as increase of macromonomer content. The branched‐PS exhibited the growing elongational viscosity function comparing with linear PS. This prominent effect on the elongational flow behavior can be explained by the molecular architecture of the branched‐PS. © 2009 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 47: 2226–2237, 2009     

Theoretical Analysis of Super-Resolution Optical Disk Mastering Using a Photoreactive Dye Mask Layer

The super-resolution mastering of read-only optical disks using a photoreactive bleachable dye mask layer was theoretically analyzed. Equations have been derived which describe the photoreactions of the resist layer and mask layer. A numerical simulation based on these equations showed that the transmittance of the mask directly affects the quality of the formed pit shape. A high-quality pit shape is obtained by using a low transmittance mask.     

Crosstalk Suppression in Header Recognition Unit Using Time-Space Conversion

We demonstrate a suppression effect of a crosstalk among a target and similar header signals using the header recognition filter designed by a design technique of the multiple-object discriminant filter.     

Design and Evaluation of Computer Generated Hologram with Binary Subwavelength Structure Designed by Deterministic Process

A binary subwavelength structure for multilevel phase modulation can be designed by our previously proposed deterministic design method without iterative optimization method. To use our design technique in various applications of a computer generated hologram (CGH) like an array illuminator, beam-shaping, signal processing, and so on, an image quality of a reconstructed image from a CGH has become much more important. In this paper, we verify the image quality of a reconstructed image from a CGH designed by our method in terms of the modulation transfer function (MTF) and the spatial resolution. Simulation results show that our technique can theoretically achieve a MTF of more than 99% over a wide range and a spatial resolution of less than 9.66μm.     

Anion-selective properties of alkali metal-free lead phosphate glasses containing silver chloride and their application in an ion-selective electrode

Alkali-free lead phosphate glasses containing silver chloride have been developed for anion responsive sensors. From measurements of the final glass compositions by electron probe microanalysis, it became clear that some of chloride ions in the glass bulk were not volatilized during the glass melting process. Compared with phosphate glasses containing silver oxide, the new glass electrodes containing silver chloride could respond more rapidly, although the response behaviour for anionic species were similar. From the electrode potential vs. time curve for the anionic species, the potential rapidly reached equilibrium when these concentrations varied from 10^?5 to 10^?2 M. The response times, t₉₅, to thiocyanate of the new glass electrode and the phosphate glass electrode containing silver oxide were 30 and 110 s, respectively. Moreover, the response time required for an initial potential change with a concentration jump of thiocyanate with the new glass electrode was found to be independent of the membrane thickness within about 2 mm and of the measuring temperature between 15 and 40°C. It is concluded that the diffusion process of species such as silver ion in the glass bulk does not take part in the initial part of the response behaviour.     

Novel regular network polyester films from benezenetricarboxylic acids and glycols

Novel regular network polyester films were prepared from benzenetricarboxylic acids of trimesic (Y) and trimellitic (Z) acids, and glycols of ethylene (2G), tetramethylene (4G), and hexamethylene (6G) glycols. Prepolymers prepared by melt polycondensation for a short period within 1 h were cast from a DMF solution and successively post-polymerized at various temperatures and times to form a network. The resultant films were transparent, flexible, and insoluble in any solvents. Distortion temperature measured by a penetration mode of thermomechanical analysis (TMA) increased with increasing post polymerization time and temperature, and leveled out at 222, 168, 125 and 75°C, for the 2GY, 2GZ, 4GY, and 6GY films, respectively. Temperatures close to 400°C at which the probe had completely penetrated corresponded to the thermal decomposition temperature of these films. Two broad but strong peaks in the x-ray diffraction curves appears for the 2GY, 4GY, and 6GY, suggesting the formation of some ordered supramolecular structure owing to the regular network formed by symmetrical trimesic acid moiety, and the intensity of diffraction peaks became higher with increasing length of the methylene chain of the glycol monomer. Densities of the 2GY and 2GZ films decreased with increasing post-polymerization time and temperature. Tensile strength and Young's modulus increased and elongation decreased with increasing network formation. These tensile properties was affected by the chemical structure of the network films.