Birefringence control by hydrogen bonding on compatible polymer pair composed of hydrogenated ring‐opening polymer and modified polystyrene

A new polymer blend composed of a hydrogenated ring‐opening polymer (HROP) with an ester group and hydroxyl functionalized polystyrene (HFP) produced the excellent transparent materials which enabled a precise birefringence control in keeping with the other physical properties for optical film use. The blend with a composition from 0.28 to 0.35 for the HFP weight fraction showed an extraordinary wavelength dispersion, transmitting through a zero birefringence point at the critical fraction of 0.45, while each polymer showed an ordinary wavelength dispersion. The observed excellent transparency even above those of the glass transition temperature was attributed to a depressed phase separation that resulted from strong hydrogen bond between the ester and hydroxyl groups. An IR analysis of the film demonstrated a remarkable red‐shift in the carbonyl peak with an increase of the hydroxylated polystyrene content, indicating a strong hydrogen bond between those groups. This new polymer blend provides a useful design to achieve practical demands for film use, both optical and mechanical under the fabrication conditions using the melt extrusion technique. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3132–3143     

Microstructure change in deuterium implanted CLAM steel induced by electron irradiation

As Reduced Activation Ferritic/Martensitic (RAFM) steel is considered the primary candidate for use as a structural material in fusion power reactors,many countries are developing different kinds of RAFM.China is developing new CLAM (China Low Activation Martensitic) steel.The study investigates microstructural changes in CLAM steel implanted with deuterium ions induced by 1250 keV electron irradiation from R.T.to 873 K,and observes both the growth and shrinkage of the defect clusters produced by deuterium ...     

Unexpected formation of benziphthalocyanine dimer: An easily synthesizable dimer of phthalocyanine analogue

Methylene-bridged benziphthalocyanine dimer 2 was unexpectedly generated by the reaction of dihydroxybenziphthalocyanine 1 and formaldehyde in the presence of a catalytic amount of a base at room temperature. Single-crystal X-ray diffraction analysis of 2 revealed a V-shaped structure. Dimer 2 exhibited longer-wavelength absorption and fluorescence bands than monomer 1 in the near-IR region.     

Regioselective Alkylation of Thiazolylsulfonamides: Direct and Efficient Synthesis of 3‐Alkylthiazolidene Derivatives

Various N‐3‐alkylated thiazolidenesulfonamide derivatives were efficiently prepared by the direct endo‐selective alkylation of thiazolylsulfonamides. The effects of different bases and solvents were investigated, and the NaH–THF combination was found to be the most effective at conferring high yields and endo‐selectivity.     

Experimental investigation of amplitude death in delay-coupled double-scroll circuits with randomly time-varying network topology

Nonlinear Dynamics - The present study experimentally investigates amplitude death in delay-coupled double-scroll circuits with a time-varying network topology that randomly changes at a regular...     

Characterization of amorphous hydrogenated carbon formed by low-pressure inductively coupled plasma enhanced chemical vapor deposition using multiple low-inductance antenna units

Three-dimensional plasma enhanced chemical vapor deposition (CVD) of hydrogenated amorphous carbon (a-C:H) has been demonstrated using a new type high-density volumetric plasma source with multiple low-inductance antenna system. The plasma density in the volume of phi 200 mm x 100 mm is 5.1 x 10(10) cm(-3) within +/-5% in the lateral directions and 5.2 x 10(10)cm(-3) within +/-10% in the axial direction for argon plasma under the pressure of 0.1 Pa and the total power as low as 400 W. The uniformity of the thickness and refractive index is within +/-3.5% and +/-1%, respectively, for the a-C:H films deposited on the substrates placed on the six side walls, the top of the phi 60 mm x 80 mm hexagonal substrate holder in the pure toluene plasma under the pressure is as low as 0.04 Pa, and the total power is as low as 300 W. It is also found that precisely controlled ion bombardment by pulse biasing led to the explicit observation in Raman and IR spectra of the transition from polymer-like structure to diamond-like structure accompanied by dehydrogenation due to ion bombardment. Moreover, it is also concluded that the pulse biasing technique is effective for stress reduction without a significant degradation of hardness. The stress of 0.6 GPa and the hardness of 15 GPa have been obtained for 2.0 microm thick films deposited with the optimized deposition conditions. The films are durable for the tribology test with a high load of 20 N up to more than 20,000 cycles, showing the specific wear rate and the friction coefficient were 1.2 x 10(-7) mm3/Nm and 0.04, respectively.     

Synthesis of new photoresponsive polyesters containing norbornadiene moieties by the ring‐opening copolymerization of donor–acceptor norbornadiene dicarboxylic acid anhydride with donor–acceptor norbornadiene dicarboxylic acid monoglycidyl ester derivatives

The ring‐opening copolymerization of donor–acceptor norbornadiene (D–A NBD) dicarboxylic acid monoglycidyl ester derivatives with D–A NBD dicarboxylic acid anhydride was performed with tetraphenylphosphonium bromide as a catalyst in toluene to produce new norbornadiene (NBD) polyesters containing D–A NBD moieties in the main chain and in the side chain in one step in good yields. The photoisomerization of the D–A NBD moieties in these polyesters proceeded very smoothly to give the corresponding quadricyclane groups. Because these NBD polyesters contained many NBD moieties in the polymer chain, they had the highest capacity for heat storage in the D–A NBD polymers reported so far. The stored thermal energy of the irradiated polyesters was evaluated by differential scanning calorimetry analysis to be approximately 150–190 J/g. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4412–4421, 2005     

Frequency dependence of acoustic properties of aqueous glucose solutions in the VHF/UHF range

The bioultrasonic spectroscopy system was employed for measurements of velocity and attenuation coefficient of glucose solutions in the VHF/UHF range. The relation between the slope of the square of velocity and the relaxation parameters, and the relation between the frequency exponent on attenuation coefficient and the relaxation parameters are investigated. In order to carry out numerical calculations, a model for a single relaxation process is employed, wherein the attenuation coefficient is expressed as (A/( 1 + (f/falpha)2) + B)f2 where falpha is the attenuation relaxation frequency, and A and B are constants. The numerical calculations show that the slope of the square of the velocity is determined uniquely by the velocity relaxation frequency fv and v(infinity)2 - v(0)2 where v0 is the zero-frequency velocity and v(infinity) is the infinite-frequency velocity, and that the frequency exponent on the attenuation coefficient is determined uniquely by falpha and A/B. For experimental considerations, the velocities and the attenuation coefficients of 5, 15, and 25% concentration aqueous solutions of glucose were measured in the frequency range 20 to 700 MHz. The data for the 5 and 15% aqueous solutions can be explained using the single relaxation model. However, the data for the 25% aqueous solution suggest the existence of multirelaxation processes.     

Ignition enhancement by addition of NO and NO2 from a N2/O2 plasma torch in a supersonic flow

The effects of NO and NO₂ produced by using a plasma jet (PJ) of a N₂/O₂ mixture on ignition of hydrogen, methane, and ethylene in a supersonic airflow were experimentally and numerically investigated. Numerical analysis of ignition delay time showed that the addition of a small amount of NO or NO₂ drastically reduced ignition delay times of hydrogen and hydrocarbon fuels at a relatively low initial temperature. In particular, NO and NO₂ were more effective than O radicals for ignition of a CH₄/air mixture at 1200 K or lower. These ignition enhancement effects were examined by including the low temperature chemistry. Ignition tests by a N₂/O₂ PJ in a supersonic flow (M = 1.7) for using hydrogen, methane, and ethylene injected downstream of the PJ were conducted. The results showed that the ignitability of the N₂/O₂ PJ is affected by the composition of the feedstock and that pure O₂ is not the optimum condition for downstream fuel injection. This result of ignition tests with downstream fuel injection demonstrated a significant difference in ignition characteristics of the PJ from the ignition tests with upstream fuel injection.