Yu. G. Kryazhev

Investigation of thermochemical transformations of cellulose triacetate, petroleum pitch, and compositions based on them by differential-thermal and mass-spectrometric analyses

Conclusions-- The effect of preliminary thermooxidative treatment on the pyrolysis processes of CTA, petroleum pitch, and CTA—pitch compositions [40:60% by wt.] has been investigated.-- The polyconjugated aromatic systems which are contained in pitch or which are developed during thermooxidation apparently aid in the occurrence of thermal transformations in the CTA which are connected up with reactions of splitting out and with the development of three-dimensional structures, which leads to a loss in the ability of the composition to melt during subsequent pyrolysis.

Infrared spectroscopic studies of the thermal transformations of fibres from a cellulose triacetate- petroleum pitch composition

Conclusions-- The thermal transformations of fibres from a CTA-petroleum pitch composition and from the components of the composition individually have been investigated by IR spectroscopy.-- An increase in content of aromatic structures takes place in petroleum pitch as a result of heat treatment in air; this is connected with the occurrence of a number of reactions (thermal polycondensation, splitting-out of easily volatile products). In the CTA, structural-chemical transformations take place, which lead to its crystallization.-- For the CTA-pitch composition, processes take place upon heat treatment which are not described by an additive scheme. The increase in content of aromatic structures in the fibre from a CTA-pitch composition proceeds more rapidly than in the individually taken components; this is probably explained by a catalytic effect of polyconjugated systems in the pitch on processes of splitting-out low-molecular-weight products upon heating the CTA.

Modifying effect of additions of 1,2-dimethyl-5-vinylpyridinium methylsulfate to viscose

ConclusionsThe modifying effect of additions of 1,2-dimethyl-5-vinylpyridinium methylsulfate (DVPS) to viscose has been investigated.It has been found that the use of DVPS as a modifier makes it possible to obtain viscose textile and technical yarns which are equivalent to industrial yarns in physicomechanical characteristics.

Effect of 1,2-dimethyl-5-vinylpyridinium methylsulfate on properties of viscose

ConclusionsAddition of 1,2-dimethyl-5-vinylpyridinium methylsulfate to viscose in an amount of 5–50% based on the weight of α-cellulose does not lead to a specific interaction of it with sulfur-containing components of the viscose and does not exert any important effect on the technological properties of the viscose or its ability to form fibres.In the spinning stage, the additive introduced behaves as a modifier which retards neutralization of the fibre being spun.

Reaction of cellulose xanthate with chromium compounds by UV spectroscopy

ConclusionsThe type of chemical bond in the chromium compounds obtained which are based on cellulose xanthate has been ascertained.It has been shown that, as a result of an oxidation-reduction reaction between the thiocarbonate groups of the cellulose xanthate and K2Cr2O7 (in acid medium), a chromium xanthate is formed which has a covalent type of bond between the sulfur atoms and chromium.

Preparation of manganese dioxide dispersions in dimethylformamide and their use for spinning filled fluoroplastic fibres

ConclusionsThe properties of manganese dioxide dispersions in dimethylformamide in the presence of various surface-active substances (SAS) have been investigated.It has been found that the use of SAS aids in loosening the structure of the fluoro-resin fibre spun with no filler, nitrogen-containing SAS exerting a more significant effect on the sorptive properties of the Ftorlon fibre.The use of SAS not only facilitates dispersion of the filler, but also exerts a significant effect on the porosity of the filler fluoro-resin fibre.

Preparation of ftorlon fibre filled with manganese dioxide

ConclusionsThe possibility of obtaining catalytic fibres by introducing the catalyst as a filler into the structure of Ftorlon fibre has been established.Sorptive properties of Ftorlon fibre spun in the absence of filler as a function of the amount of polyethylene glycol added to a spinning solution of the fibre-forming polymer and of the spinning conditions have been investigated, as well as the morphology of the surface of the modified Ftorlon fibre.It has been discovered that, by choosing the composition of the spinning solution and the conditions of spinning Ftorlon fibre filled with manganese dioxide, it is possible to obtain a fibre having a porous structure which ensures accessibility of the filler to reagents.

Preparation of an anion-exchange viscose fibre by graft polymerization to cellulose during the spinning process

ConclusionsThe fundamental possibility of modifying viscose fibres by graft polymerization of DVPS by a continuous method during the course of spinning has been demonstrated.The fibre obtained has anion-exchange properties and has satisfactory sorptive and physico-mechanical indices, comparable with those of TsM-A2 fibre.