Study of the structure and properties of composite chemisorbents made from carbon fibres

Abstract

661.18:667.4 and O. S. AlchanovaThe kinetic characteristics of synthesis and hardening of the polymer cation-exchange matrix in a carbon fibre were investigated, the effect of the chemical nature of the fibre filler on the structure of the ionexchange matrices formed was noted, and the possibility of purposeful regulation of their structural characteristics was demonstrated. It was shown that the chemisorbents developed can be used in treatment of wastewaters to remove chloride and sulfate ions. Chemisorption blocks with combined Polikon CCFM (with anion-and cation-exchange polymer matrices) were recommended for more efficient treatment.The consumption of a significant amount of tap water by industry, its reaction with different substance sin the manufacturing cycle, and in the final analysis, pollution, makes it necessary to treat the water before discharging it. Investigators are focusing great attention on selection of the treatment method as a function of the requirements for the quality and degree of treatment of the water. Carbon fibres and composite chemisorbents made from them are considered the most effective materials capable of solving the most complex water treatment problems.Due to ordering of the structure of carbon fibres (CF) made from acrylonitrile copolymers, the unit of their volume contains a large amount of meso-and micropores positioned perpendicular to the axis of the fibre and accessible from the outer surface, which ensures their high kinetic activity with respect to sorbed substances in comparison to granulated carbon sorbents [1]. The high chemical resistance (to acids and bases) and thermal stability (up to 350°C in air) and the relatively high selective and sorption characteristics of CF make their use feasible as fillers for composite chemisorptions fibre materials (CCFM).Carbon fibres were used in the previous study to increase the performance properties of Polikon chemisorbents as the fibre base for synthesis and formation of a cation-active polymer matrix. The studies showed (Fig. 1) that the rate and degree of wettability with a hydrophilic impregnating composition have a smaller effect on the CF in comparison to PAN fibre, which is due to the hydrophoby of the graphitized structure.In view of the features of the structure and chemical nature of the fibre filler, the effect of CF on the kinetics of synthesis and hardening of the cation-exchange matrix was investigated by differential scanning calorimetry. Synthesis and formation of the polymer matrix in carbon fibres take place with a higher initial rate. The overall heat effect of the polycondensation reaction |ΔH| (Table 1) increased and the maximum was identified in the low-temperature region (45°C). Hardening takes place with an increase in the heat effect by 1710 J/g, which indicates the formation of a more thickly crosslinked spatial structure of the polymer matrix.Manufacturing methods and process parameters for manufacturing Polikon CCFM on CF were developed based on an analysis of the results of the studies, pilot-labora...

Features of Synthesis of Anion Exchange Matrix “Polikon A” with Oxidated Ultrafine Additives on Lavsan Textile Bases

“…Earlier, we carried out a number of studies on various ion-exchange matrices reinforced with chemical fibers: polypropylene (PP), viscose (VF), polyacrylonitrile (PAN), phenol formaldehyde novolac (PFN), etc. [5,6].…”

“…This study is the continuation of comprehensive studies [2][3][4][5][6], for the first time, it proposes the use of Lavsan fabric as a promising fibrous base, as well as the possibility of introducing ultrafine silicon, iron and nickel oxides into the composition of the created compositions, and the influence of the textile structure of the fiber base on the physical, chemical, and sorption characteristics of developed membranes is studied.…”

“…EXPERIMENTAL "Polikon" materials were obtained by polycondensation filling of a fibrous matrix with a monomerization composition and further formation of an anionite matrix both on the fiber surface and in its structure [3][4][5]. The technological process consisted of prepreparation of raw materials, obtaining of monomerization compositions (epichlorohydrin + polyethylene polyamine) and their application onto a fibrous filler, synthesis, curing-forming of a spatial network of polymer matrices on the surface and in the volume of the system.…”