M. F. Lebedeva

Procedures for preparing chitin-based fibers

Data on preparation of chitin threads for the fabrication of absorbable suture materials, dressings, and biodegradable substrates for the growth of human skin cells (keratinocytes and fibroblasts) are analyzed.

Formation of Physical Thermally Reversible Gels in Solutions of Methyl Cellulose in Water and Dimethylacetamide and Properties of Films Thereof

Gelation conditions in solutions of methyl cellulose in water and dimethylacetamide were studied. The gelation mechanisms were studied by X-ray diffraction and photocolorimetry, and their differences in the two systems were revealed. The physicomechanical properties of methyl cellulose films prepared from solutions with preliminary gelation were determined.

Composite Fibers Based on Chitin and Cellulose

Composite fibers were produced by mixing of chitin and cellulose solutions with subsequent molding from these solutions under standard conditions. The effect of composition of systems on the structural modification and the deformation-strength characteristics of the fibers was studied.

Compatibility of carboxymethyl cellulose ionized to various degrees with poly-N-vinylformamide in composite films

Composite films were obtained from aqueous solutions of blends of carboxymethyl cellulose ionized to various degrees and poly-N-vinylformamide. The composition ranges in which the polymers are compatible were determined by solvent vapor sorption and by dynamic mechanical analysis. The heat resistance of the films and the interaction of the polymers in the solid state were examined by DSC, TGA, and Fourier IR spectroscopy.

Interpenetrating polymer networks based on diisocyanates and polar monomers

Abstract Compatible interpenetrating polymer networks systems (IPS) have been obtained by two-stage polymerization of a mixture of diisocyanates (M 1 ) with various different polar monomers (M 2 ) initiated by catalytic systems based on tertiary amines. In the first stage, a polyisocyanate network (P 1 ) is formed and then M 2 is polymerized on a regenerated active centre with the formation of a linear polymer (L 2 ) specially arranged in P 1 . The essential features of the formation of IPS of this type are considered. Some physico-mechanical and thermal characteristics are reported.

Polymeric Materials Derived from Vanillic Acid

Film and fibrous materials derived from vanillic acid, one of promising products from processing of industrial lignin, were prepared and characterized. Thermochemical reactions of degradation and carbonization of films and fibers of vanillic acid polyesters and polyamides were considered, and the main relationships of thermal transformations of the materials were revealed.

Composite Fibers Based on Chitin

Composite fibers containing chitin and cellulose ethers (methyl, hydroxyethyl, and hydroxypropyl cellulose) and also chitin and polyvinylpyrrolidone were prepared. The effect of the ratio of system components and also the molecular weight of polyvinylpyrrolidone on the deformation-strength characteristics of the composite fibers and their supramolecular organization was studied.