Both annual (cotton, flax, hemp, etc.) and perennial (trees and grasses) plants can serve as a source of cellulose for fiber production. In recent years, the perennial herbaceous plant miscanthus has attracted particular interest as a popular industrial plant with enormous potential. This industrial crop, which contains up to 57% cellulose, serves as a raw material in the chemical and biotechnology sectors. This study proposes for the first time the utilization of miscanthus, namely Miscanthus Giganteus “KAMIS”, to generate spinning solutions in N-methylmorpholine-N-oxide. Miscanthus cellulose’s properties were identified using standard methods for determining the constituent composition, including also IR and atomic emission spectroscopy. The dry-jet wet method was used to make fibers from cellulose solutions with an appropriate viscosity/elasticity ratio. The structural characteristics of the fibers were studied using IR and scanning electron microscopy, as well as via X-ray structural analysis. The mechanical and thermal properties of the novel type of hydrated cellulose fibers demonstrated the possibility of producing high-quality fibers from miscanthus.

A method for obtaining nonwoven precursors of carbon materials based on natural and viscose fibers was developed. Bast (flax and hemp) fibers were used as sources of natural fibers which were previously processed in order to remove impurities and enrich with the alpha fraction of cellulose. The structure, morphology, and chemical composition of natural and viscose fibers were studied by X-ray, SEM, and IR spectroscopy. The mechanical characteristics of the fibers were determined. The results of studies of the thermal behavior of mixed materials based on viscose, flax, and hemp fibers at temperatures up to 1000 °C were presented. The introduction of a small fraction of natural fibers into viscose (up to 30

The paper discusses experimental techniques for pulping, bleaching, and creating manmade fibers based on Na-sulfite and Mg-bisulfite dissolving pulps utilizing a dry-jet wet spinning procedure with solutions in N-methylmorpholine-N-oxide. After pulping, Mg-bisulfite pulp had a cellulose yield of 46.1

Optical interferometry has been employed to study the mass exchange processes that accompany the dissolution of PAN ternary copolymer and to determine limiting copolymer concentrations in solutions in different crystal hydrate forms of N-methylmorpholine-N-oxide (NMMO). Turbidity spectra, interferometry, and optical microscopy have been used to study the effect of the nature of a precipitant on the phase transformations in the system during solution coagulation and to find the precipitation numbers upon the addition of water and aqueous NMMO solutions (20–50 wt

The production of long flax fiber for the subsequent production of textile yarn is accompanied by the formation of a significant amount of waste—noils, which is a mechanical mixture of long and short flax fibers and shives. Comparative studies of the structure and chemical composition of the fibrous fraction of noils and shives were carried out using IR spectroscopy. The solubility of shives and flax noils in N-methylmorpholine-N-oxide (NMMO) was studied, a comparative analysis of the rheological behavior of solutions of flax and wood cellulose was carried out and the optimal temperature–concentration conditions for obtaining flax fibers from noils were determined. It was shown for the first time that using the method of solid-phase activation of the cellulose-solvent system makes it possible to obtain fibers in a short period of time (no more than 10 min). The structure of both the raw material and the resulting fibers was studied by X-ray diffraction analysis. The thermal properties of a new type of cellulose fibers was evaluated. The complex of the conducted studies allows us to consider flax fibers from noils along with flax fibers from long-staple flax, as a real alternative to fibers from wood pulp.

The kinetics of dissolution of an acrylonitrile copolymer in various crystal hydrates and in a 12% cellulose solution in N-methylmorpholine-N-oxide in a wide temperature range is studied by optical microscopy. The rate and features of the dissolution process are determined by the hydrated form of the solvent. The activation energy of dissolution of the systems under study is calculated using the first-order kinetics. The kinetic characteristics of dissolution of polyacrylonitrile and cellulose in N-methylmorpholine-N-oxide can be used as a basis for finding the optimal temperature–time parameters for the process of obtaining joint solutions of polyacrylonitrile and cellulose, as well as new composite precursors of carbon fibers.