Volume 42 Issue 10, October 2010

The synthesis and photo-polymerization of hyperbranched polyesters containing pendant methacryloyl groups (HBPE-MA) were examined. Polycondensations of 1,4-bis(chloromethyl)benzene (BCMB) with 1,3,5-benzenetricarboxylic acid (BTCA) proceeded very smoothly to give the soluble hyperbranched polyesters (HBPE) in satisfactory high yields using 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). Furthermore, HBPE-MA was synthesized by the reaction of HBPE with methacrylic acid (MAA) by the DBU method. The photo-induced radical polymerization of HBPE-MA was performed in the presence of 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-2-one (Irgacure 907) as a photoinitiator in the film state upon UV irradiation to afford the insoluble cured film.

Poly(arylene sulfone)s (PASs) containing 9,9′-spirobifluorene (SBF) skeleton in the main chain were synthesized in high yields by the oxidations of the corresponding poly(arylene thioether)s. The PASs exhibited good thermal stability (T_g 257–370 °C, T_d5>400 °C under nitrogen), and showed high solubility in ordinary organic solvents, such as CHCl₃, N-methylpyrrolidone (NMP) and N,N-dimethyl formamide (DMF). All films of PASs showed higher refractive indices in the range 1.65–1.67 at 587.6 nm than those of commercially available polysulfone, whereas it hardly showed birefringence. These excellent optical and thermal properties are derived from the C₂ symmetry and high aromatic component of SBF moiety. Polymer: (i) High refractive index, (ii) Low birefringence, (iii) High thermal stability, (iv) High transparency, (v) High solubility and (vi) Less coloration.

Hyperbranched polysiloxanes were synthesized by polyhydrosilylation of silsesquioxane derivatives and vinyl derivatives in the presence of Karstedt's catalyst. The obtained hyperbranched polymers were soluble in common solvents and exhibit good thermal stability. The refractive index values of the obtained polymers tend to decrease with increasing structure size of co-monomers.

Polypropylene (PP)-knitted fabrics were finished with β-cyclodextrin (β-CD) through their crosslinking with citric acid (CTR). The polyCTR–β-CD polymer-coated fibers were wash resistant. We report that the rate of immobilized CD was controlled by temperature and curing time. The weight increase of the fabrics on their modification with native β-CD and CTR could reach 30 %wt. The treated PP supports were dyed by applying classical dyeing processes involving disperse, acid and reactive dyes. Standard tests of wash fastness (shade change and staining) were conducted and showed that all dyes were fixed, because of inclusion complexation with the immobilized cavities on one hand and sorbed hydrogen or ionic bonds that also occurred between the polyCTR–β-CD coating and the tested dyestuffs on the other.

X-ray scattering from an organogel made from discotic triazine triamide was measured at SPring-8 at a quite wide q range of 0.050 nm⁻¹ <q <20 nm⁻¹. Analyses revealed (1) an amorphous nature of the molecular stacking at a distance of 0.32 nm, (2) the presence of a semiflexible rod-like scattering object with a radius of 1.3 nm and a Kuhn length of 55 nm and (3) branching of the cylinder formed at the gel state.

The reaction in the presence of poly(γ-glutamic acid) (γPGA) proceeded faster than that without γPGA and the larger molecular weight γPGA was slightly more efficient to catalyze the reaction.

The molecular chaperone function of polysaccharide nanogel was demonstrated for the folding of newly synthesized green fluorescent protein (GFP) in a cell-free protein synthesis system. Nanogel comprising cholesteryl group-bearing pullulan (CHP) trapped unfolded or partially folded GFP expressed in the cell-free system. The structure of the CHP nanogel was disrupted by the addition of cyclodextrins, and the protein complexed with the nanogel was released and folded into the mature form.

For the purpose of an electric paper application, alginate hydrogel particles were prepared. To increase their zeta potential for well response by electric fields, their surface were modified chemically. Electro-response behaviors were observed between comb-shaped electrodes. It was found that surface-modified alginate hydrogel particles were well responded by applied low voltage 4–9 V.

Permeation of model drugs with different molecular weights through a bioconjugated membrane having antigen–antibody complexes as reversible crosslinks was investigated in the absence and presence of a target antigen. The bioconjugated membrane regulated the drug permeation in response to the concentration of a target antigen. This paper focuses on the effect of the molecular size of the drugs on controlled permeability of the antigen-responsive membrane.