A computer aided molecular design (CAMD) technique was applied to investigate a possible packing model for cellulose triacetate I (CTA I). The model was constructed based on structural data obtained by CP/MAS ¹³C NMR. The starting model was determined by molecular mechanics (MM) calculations on the basis of a model proposed previously by X-ray diffraction data. Molecular dynamics (MD) calculation data indicated the CTA I crystalline has a one-chain, monoclinic structure with unit cell parameters of a = 1.19 nm, b = 0.65 nm, c (fiber repeat) = 1.08 nm, and γ = 104°; the torsion angles χ (C4-C5-C6-O6) are gauche-gauche (gg); and that the side chains are one kind of conformation, respectively. This structure reveals that a glucopyranose residue becomes an asymmetric unit, whereas the previous model contains two independent chains per unit cell with P2₁. Hence, we propose a refined structure of CTA I.

View full abstract

A novel Zn(II)-Poly(acrylonitrile-co-silk fibroin peptide) complex was synthesized by copolymerization of acrylonitrile and a new complex macromonomer consisting of Zn ion and modified silk fibroin peptide by acryloyl chloride with vinyl groups. we examined effects of using distilled water and diluted hydrochloric acid as precipitant for the obtained resulting complex solution in the termination stage of copolymerization on the content of Zn(II) of copolymers. And the copolymer complexes containing Zn ions of difference content were obtained. By the typical IR peaks of pure poly(acrylonitrile-co-silk fibroin peptide) and its complexes, the ligand coordination occurs mainly through oxygen atom and nitrogen atom from the amide carbonyl group and no complex formation between the CN group and Zn ion were presumed. The other, by absorbing various metal ions on pure copolymers, several copolymer metal complexes could be also obtained. However, the results eluting Zn²⁺ from powder of copolymer complexes by diluted HCl indicated their difference stabilities, the complex synthesized by vinyl groups had better stability than that obtained by absorbing metal ions. All copolymer complexes exhibited significant odor-removing activity. And the sample of higher content of Zn ion reveals good antibacterial activity.

View full abstract

Sheerness of pantyhose is one of the important factors of aesthetic properties, and greatly influenced by the structural characteristics of single covered yarn and color effects. In order to enhance the beauty of women's legs, the development of a new yarn and product are proposed. The appearance of pantyhose is examined by means of Semantic Differential Method, and the relationships between color and the structural characteristics of single covered yarn are discussed. The results show that the appearance and sheerness of pantyhose are greatly influenced by color for the same single covered yarn characteristics, and/or by yarn characteristics for the same color, i.e., the core yarn count, the covering yarn count, the covering level, and the filament number of covering yarn. Furthermore, it is effective for the Japanese women's leg to design the chromaticity value Δa^*⁄a^* < 0.15, Δb^*⁄b^* < 0.10 between leg and color of pantyhose. (a^*, b^* of a uniform color space) It will be necessary to inscribe color value of a pantyhose on the package and to find their legs color value. Only then will improve sheerness of pantyhose.

View full abstract

Delftia acidovorans (IFO13582) was grown in fed-batch and chemostat cultures with n-butyric acid and 1,4-butanediol as mixed carbon substrates. In fed-batch cultures, the synthesis rate of the polymer was considerably increased with the increment of the cell growth. The polymer content increased and reached to a maximum of 27 wt% with increasing the cell dry-weight of ca. 4.4-5.2 g/l at 26 °C for 72 h and the maximum 4HB unit composition of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] was slightly low value of ca. 66 mol%. Whereas the maximum 4HB unit composition of P(3HB-co-4HB) obtained by the fed-batch culture with lower cell concentration of ca. 2.5 g/l reached to 94 mol% though the content of P(3HB-co-4HB) was always low, at ca. 13 wt%.

View full abstract

Cross sections of rosin-sized handsheets were prepared using commercial razors, a focused ion beam (FIB), or uncoated scalpels, and analyzed by using time of flight secondary ion mass spectrometry (TOF-SIMS). CF⁺ ions, which originated from fluorocarbons in the razor coating agents, were strongly detected in cross sections prepared with commercial razors. Rosin sizes could not be identified in cross sections prepared by using FIB. Chemical compositions on the very thin surface layers of cross-sections were changed by FIB processing. CF⁺ ions were hardly observed on the cross sections cut with uncoated scalpels. TOF-SIMS images of these cross sections revealed that rosin sizes existed both on pulp-fiber surfaces and inside pulp-fiber walls. The distribution of rosin sizes inside pulp-fiber walls was relatively even. Uncoated scalpels were most appropriate for preparing cross sections of rosin-sized handsheets for analyzing by TOF-SIMS.

View full abstract