Synthesis of Polyol Tetrabromophthalate and Its Use as a Component for Preparing Foamed Polyurethanes of Reduced Flammability

A procedure was suggested for preparing brominated polyols of reduced viscosity for the synthesis of foamed polyurethanes of reduced flammability. The flame-retarding action of the synthesized polyol tetrabromophthalate in polyurethane was studied in comparison with that of other widely used flame retardants. Evaluation of the effect exerted on the flammability of the polurethane compound by the polyol tetrabromophthalate synthesized, melamine, and aluminum hydroxide shows that all the samples containing flame retardants are self-extinguishing. The shortest combustion time was observed for the sample containing 6% polyol tetrabromophthalate synthesized. The sample containing as a flame retardant additive solely the synthesized polyole tetrabromophthalate also exhibits the highest performance as a heat-insulating material from the viewpoint of thermal conductivity.

     

The mean-value theorem for elliptic operators on stratified sets

In this paper, an analog of the mean-value theorem for harmonic functions is proved for an elliptic operator on the stratified set of “stratified” spheres whose radius is sufficiently small. In contrast to the classical case, the statement of the theorem has the form of a special differential relationship between the mean values over different parts of the sphere. The result is used to prove the strong maximum principle.     

Improvement of adhesion strength of adhesive joints of rubbers during repair works

The possibility of significantly improving the adhesion strength of adhesive joints of fabric-backed vulcanized rubbers by the additional sandpapering of a rubber surface is shown.     

Chemical structure of fibers of ultra-high-molecular-weight polyethylene upon ion-beam treatment and post-irradiation grafting of acrylic monomers

Surface modification of fibers fabricated from ultra-high-molecular-weight polyethylene by pulsed ion-beam treatment was studied. The structure and morphology of the surface layer were examined by the IR MFTIR method and X-ray diffraction analysis. A post-irradiation grafting of a number of acrylic monomers to the fiber surface was performed.     

New copolymer gels based on <Emphasis Type="Italic">N</Emphasis>,<Emphasis Type="Italic">N</Emphasis>-dimethylacrylamide and crown-containing allyl derivative of 1,8-naphthalimide as optical sensors for metal cations in an organic medium

New copolymer gels bases on N,N-dimethylacrylamide and a crown-containing allyl derivative of 1,8-naphthalimide showing intense visible fluorescence have been prepared. The effect of metal cations on the optical properties of the fluorescent monomer and its copolymer gels has been studied. These gels have been found to exhibit optical response selectivity with respect to binding of alkaline-earth metals in an acetonitrile medium.     

Maximum principle for subharmonic functions on a stratified set

The strong maximum principle is proved for solutions of the inequality ??u ?? 0 on a stratified set.     

New peptide from seeds of <Emphasis Type="Italic">Cicer arietinum</Emphasis>

The pure peptide YZDCM was isolated from seeds of Cicer arietinum and assigned to the homologous class of defensins according to molecular weight and N-terminus amino-acid sequence.