Volume 43 Issue 4, April 2011

1,3-Diketone moiety fixed between organic polymer and inorganic nanocrystal imitated sandwich-like structure can provide highly stabilized luminescent materials featuring luminescent stability, durability and emission color tuning ability.

cis-1,4-Dihydro-1,4-dimethyl-1,4-diarsinine-2,3,5,6-tetracarboxylic acid dianhydride was quantitatively formed from cis-1,4-dihydro-1,4-dimethyl-2,3,5,6-tetrakis(t-butoxycarbonyl)-1,4-diarsinine treated with formic acid. X-ray crystallography suggests that the six-membered ring in cis-1,4-dihydro-1,4-dimethyl-1,4-diarsinine-2,3,5,6-tetracarboxylic acid dianhydride was in a boat conformation and was nearly flat, and the As–C=C bond angle of cis-1,4-dihydro-1,4-dimethyl-1,4-diarsinine-2,3,5,6-tetracarboxylic acid dianhydride extended to 133°. Polymerization of cis-1,4-dihydro-1,4-dimethyl-1,4-diarsinine-2,3,5,6-tetracarboxylic acid dianhydride with 1,3′-bis(4-aminophenoxy)benzene at 80 °C in DMAc for 12 h yielded a soluble polyimide, of which number-average and weight-average molecular weights were estimated to be 23 400 and 60 300, respectively. The polyimide was obtained even when polymerization was carried out at 60 °C for 24 h.

A clean post-functionalization of 7,7,8,8-tetracyanoquinodimethane polyester by a high-yielding addition reaction with electron-rich alkyne molecules provided highly colored polymer products with very stable charge-transfer bands in the visible to near-infrared region. Electrochemistry revealed elevated HOMO and LUMO levels after the post-functionalization.

The melting temperature of poly(ɛ-caprolactone) blocks, T_m,PCL, in poly(ɛ-caprolactone)-block-polyethylene is investigated as a function of the volume fraction of poly(ɛ-caprolactone) blocks in the system, φ_PCL, and compared with that in poly(ɛ-caprolactone)-block-polybutadiene, the precursor of poly(ɛ-caprolactone)-block-polyethylene with an identical poly(ɛ-caprolactone) molecular weight. T_m,PCL for poly(ɛ-caprolactone)-block-polyethylene is always higher than that for poly(ɛ-caprolactone)-block-polybutadiene, and the difference in T_m,PCL increases steadily with increasing φ_PCL.

The effect of solvent annealing treatment on the microdomain orientation of polyacrylonitrile-block-polyethylene glycol (PAN-b-PEG) copolymers has been investigated by atomic force microscopy. Heptane, toluene and thiophene were used as annealing solvent. The size of PEG domains grew gradually by the solvent annealing of heptane, toluene and thiophene in sequence. The different size of PEG domains by solvent annealing treatment was caused by the different affinity of the solvent to PEG segments. Thiophene exhibited the strongest affinity to PEG segment among the used annealing solvent.

Nylon 6/iodine complex, which was prepared with nylon 6 (polyamide-6, PA6), shows intercalated structure composed with iodine. This work reports that this intercalated structures can be modified by ageing in swollen condition; the iodinated sample modifies the primarily 1.56-nm spacing in dry condition into 1.95 nm or more larger spacing, which revealed or vanished in moist environment. Diffusion of ions or low molecules into the iodinated nylon 6 can achieve easily even in their crystallite.

X-ray reflectivity measurements are performed on polystyrene thin films supported on Si substrates at various heating and cooling rates. With decreasing thickness, the width of the glass transition (w) shows an appreciable variation that depends on the rate of temperature variation: broadening at a rate of 0.5 °C min⁻¹, no broadening at a rate of 0.05 °C min⁻¹ and narrowing at a rate of 0.01 °C min⁻¹.

The use of biodegradable polyethylene can help reduce accumulation of inert polyethylene in the environment, as well as soil pollution. The incorporation of pro-oxidant additives into polyethylene makes the polymer susceptible to physical damage caused by photolysis and chemical oxidation, rendering a reduction in physical strength. The scanning electron microscope photograph of 20% oxo-biodegradable additive-added polyethylene showing the physical damage as a larger hole of 9.67 μm caused after the ultraviolet irradiation

We synthesized Noria analogs (Noria-OEt) with 12 ethoxy groups and 12 hydroxy groups by the condensation reaction of 3-ethoxyphenol with 1,5-pentanedial in high yield and prepared negative-type photoresist composed of Noria-OEt, crosslinker, photoacid generator and quencher. The negative-working photoresist gave a resolution pattern of 35-nm half-pitch with high sensitivity (10.0 mJ cm⁻²) by an extreme ultraviolet (EUV) lithography system.

Bio-based biodegradable hydrogels were prepared by crosslinking microbial poly(γ-glutamic acid) (PGA) with L-lysine in aqueous solution in the presence of 4-(4,6-dimethoxy-1,3,5-triazin-2-yl)-4-methylmorpholinium chloride (DMT-MM) in a one-pot synthesis. The crosslinking was carried out in aqueous solution in a high yield. The gels obtained in this study were readily biodegraded in the biochemical oxygen demand test. The PGA gel and the crosslinking method by DMT-MM in aqueous solution will be applicable to the development of functional bio-based materials. WSC, water-soluble carbodiimide.

We report transparent ion conductive ionic liquid-phenol resin hybrids prepared by in situ polymerization/crosslinking of phenol monomer in ionic liquid. The transparent hybrid prepared from 20 wt% monomer concentration exhibited high thermal stability and ionic conductivity (1.0 × 10⁻³ S cm⁻¹ at 30 °C), which is comparable to the pristine ionic liquid.

Branched poly(lactic acid) was synthesized by ring-opening polymerization of lactide using castor oil as initiator. The blended film of the branched polymer and poly(L-lactic acid) was prepared by the hot-press method at 175 °C. Only a small amount of the branched polymer was enough to plasticize poly(L-lactic acid). The thermal and dynamic mechanical properties of the film were examined in detail, and the crystalline morphology of the film was observed using a polarized microscope.

The highly soluble hyperbranched oligothiophene (SH-oligothiophene), which is composed of bithiophene and N,N,N′,N′-tetraphenyl-1,3-phenylenediamine groups, is newly prepared and the photocarrier transport property of the SH-oligothiophene film prepared by spin coating from a chloroform solution is investigated by a time-of-flight method. Transient photocurrent profiles indicate that hole carriers drift preferentially compared with electrons and that dispersive transport characteristics are obtained.