Compatibility of Bombyx mori chitosan with pectin and Na-carboxymethyl cellulose in solutions

Solutions and blends of Bombyx mori chitosan with pectin and Na-carboxymethyl cellulose were studied by viscometry. The intermolecular interaction parameters and the parameter of the distance of hydrodynamic interaction of a pair of separate molecules were calculated, and the polymer compatibility was assessed.     

Nanostructures of pectin and its metal complexes

Complexes with metal ions and nanostructures of pectin from Yalongoch lemon were prepared by precipitation. The structural organization and characteristics of the resulting nanostructures were studied by electron microscopy, rheology, and potentiometric titration. A growth-stimulating effect on cotton seeds was found for pectin nanostructures containing biogenic cations.     

Acrylonitrile copolymer nanofibers and their structural characteristics

Nanofibers of an acrylonitrile copolymer (acrylonitrile-methacrylate-itaconic acid) are obtained by the electrospinning method from 51.5% NaSCN aqueous solutions at a voltage of 15 kV. The structural characteristics of these nanofibers are investigated. It is shown that, during electrospinning, the interplanar distance decreases and reflections in the range 2θ ≈ 29.5° become narrower; sorption ability likewise decreases relative to that of microfibers.     

Gel formation of solutions of fibrillar proteins during flow in a longitudinal field

The effect of gel formation in the jets of salt-containing solutions of fibrillar proteins (silk fibroin and wool keratin) in a longitudinal hydrodynamic field modeling the process of natural-silk formation in silk glands is studied. Structural transformations in macromolecules are monitored via birefringence measurements, optical rotatory dispersion, and polarization ultramicroscopy. Gel formation under the action of a longitudinal rate gradient is accompanied by the α → β-conformation transition and by the attainment of high degrees of orientation.     

Structuring of fibrillar proteins in electrodialysis of ions in a shear flow

Possibility of using electrodialysis for controlling the content of ions in structuring of silk fibroin in a shear flow was studied.     

Rheological properties of solutions of chitosan and its graft copolymer with <Emphasis Type="Italic">N</Emphasis>-vinylcaprolactam

Rheological characteristics of solutions of Bombyx mori chitosan with various molecular masses and the graft copolymer of chitosan and vinylcaprolactam during shear flow are studied. A decrease in the molecular mass of chitosan results in a substantial narrowing of the areas of hysteresis loops and their shift to higher shear rates and lower shear stresses. The presence of vinylcaprolactam blocks in a macromolecule is favorable for increasing the chain flexibility and intermolecular interactions.     

Consolidation and Melioration of Salted Sandy Soils Using a Compound of Acetone-Formaldehyde Resin with Silk Sericin

Curing of the compound of acetone-formaldehyde resin with natural silk sericin in the presence of inorganic salts and its effect on a salted sandy soil were studied.     

Determination of the degree of sulfation of <Emphasis Type="Italic">Bombyx mori</Emphasis> chitosan by conductometric titration

The degree of sulfation of chitosan samples obtained from the first time from chitin of Bombyx mori mulberry silkworm pupas was studied by conductometric titration. The extent of chitosan sulfation and a decrease in its molecular weight were evaluated by IR spectroscopy and viscometry.     

Thin-layer chromatography of the sericin,fatty waxes,and fibroin of natural silk

The method of thin-layer and high-performance thin-layer chromatography is proposed for the investigation of the isolation of sericin, fatty waxes, and fibroin from a natural silk cocoon. The chromatographic fractionation of fibroin according to molecular masses has been studied.Institute of the Chemistry and Physics of Polymers, Academy of Sciences of the Republic of Uzbekistan, Tashkent. fax (3712) 44 26 61. Translated from Kbimiya Prirodnykh Soedinii, No. 4,pp. 588–590, July–August, 1995. Original article submitted October 17, 1994.