N. K. Luneva

Synthesis and properties of cellulose phosphates

Conditions for modification of cellulose under laboratory and industrial conditions with A-1 and A-2 fire retardants as P,N-containing modifiers were examined with the aim to prepare difficultly inflammable materials. The degrees of crystallinity of the products, crystallite size, and features of their thermal decomposition in air in the range 20–500°C were examined.

Performance of intumescent fire retardant for wood

Performance characteristics of new fire-retardant formulations are studied, including their water resistance and the effect of additives.

Cellulose phosphorylation with a mixture of orthophosphoric acid and ammonium polyphosphate in urea medium

Cellulose samples with various extents of structural ordering (native cotton cellulose and mercerized cellulose) were phosphorylated with a mixture of orthophosphoric acid and ammonium polyphosphate in a urea medium. The phosphorus content and ion-exchange capacity of phosphorylated mercerized cellulose are higher than those of the initial natural polysaccharide phosphorylated under the same conditions. Modification of the glucopyranose rings of cellulose mainly occurs in amorphous regions of the polymer. The maximal rate of thermal degradation of cellulose phosphates is considerably lower than that of the initial polymers, and the degradation rate maximum is observed at 238–245°C, in contrast to the main process of dehydration and carbonization of the initial materials, occurring at 330–340°C. The results obtained can be used for preparing ion-exchange sorbents and fireproof fabrics with preset properties.

Esterification with orthophosphoric acid of cellulose samples with different extents of structural heterogeneity

Modification of cellulose samples with different extents of structural heterogeneity by esterification with orthophosphoric acid in the temperature range 140–160°C was studied. The reaction yielded cellulose phosphates containing 3.2–6.0 wt % P, with the ion-exchange capacity of 2.2–3.0 mg-equiv g−1. Introduction of phosphorus into cellulose leads to a slight decrease in the structural heterogeneity. The polymer with the lower ordering index is characterized by the higher phosphorus content, which suggests that the reaction mainly occurs in the amorphous part of the polymer.

Ion exchange properties of heat-treated NH4Cl-containing cellulose-regenerated

Ion exchange properties of carbon fibers obtained by heat treatment in a temperature range of 200–600°C in an inert atmosphere of cellulose-regenerated impregnated by 0.3–3.0 M ammonium chloride were examined.

Microporous carbons and their properties

Thermal degradation of saw dust impregnated with phosphorus-and nitrogen-containing solution with ammonium, lithium, and cesium additives in the 20–700°C range was studied by physicochemical methods. The conditions of preparing activated carbon were determined and its adsorption and structural characteristics were studied.

Composition of a wood combustion inhibitor based on a magnesium complex containing phosphorus and nitrogen

A flame retardant for wood impregnation based on a magnesium complex containing phosphorus and nitrogen was developed. It considerably reduces the wood loss in fire tests. Application of the flame retardant in an amount of 300 g m–2 allows preparation of materials with the fire performance corresponding to group I of materials. The mechanism of the fireproofing action of the flame retardant on wood and the thermal degradation of the impregnated wood were studied.

Development of new water-treatment-resistant fire- and bioprotective preparations for wood

Fire-retardant formulations for wood were developed, and the efficiency of their fireproofing properties, resistance to water, thermal decomposition, and effect of additives on these properties were studied.

Effect of fireproofing formulation modifiers on the thermal decomposition process of wood

Effect of modifiers of fireproofing formulations for wood, based on phosphorus-and-nitrogen-containing compounds, on the process of thermal decomposition and properties of wood treated with these formulations was studied.

Effect of some ammonium salts on thermal decomposition of impregnated wood and properties of activated carbons

Methods of chemical, thermal, IR spectral, and X-ray phase analysis were used to study the effect of ammonium additives NH4Cl + NH4NO3 introduced into a phosphorus-nitrogen formulation on the thermal decomposition of impregnated wood in the temperature range 20–700°C and on adsorption characteristics of the resulting activated carbon.