Abstract
It was found that the extrusion treatment of cotton cellulose in an aqueous medium, followed by drying and grinding on a hammer mill leads to a decrease in the crystallite size in the transverse direction ([110] and [100]) as a result of mechanical destruction of cellulose macromolecules, and the subsequent acid hydrolysis of cellulose in H2SO4 solutions to an increase in the size of crystallites in the transverse direction ([110], [110] and [100]) due to co-crystallization processes. It is shown that alkaline cooking of cellulose-containing material, followed by extrusion processing, washing, drying and grinding on a hammer mill leads to an increase in the transverse dimensions of crystallites in the [110] and [100] directions for flax cellulose and in the [110], [110] and [100] – for cellulose from oats and alfalfa as a result of partial removal of lignin and hemicelluloses from the cellulose-containing material.
 Differences were revealed in the sizes of the coherent scattering regions and the parameters of the crystallographic cell of cellulose samples from cotton and herbaceous plants (flax, oats, and alfalfa), as well as between samples from oats and alfalfa obtained under the same conditions with the same type of feedstock (straw).
 It has been established that the proposed stepwise technology for processing cotton and linen fibers leads to a slight decrease in the degree of crystallinity and the average degree of polymerization, which indicates that the developed technology for obtaining high-viscosity powder celluloses for various purposes is promising.
 Correlation coefficients are established between the values of the degree of ordering of the structure of cellulose samples from various plant raw materials, calculated using X-ray diffraction analysis and FT-IR spectroscopy, which make it possible to adequately compare all the known literature and experimental data.
Highlights
Экспериментальная часть3% NaOH и 0.1% H2O2 в течение 60 мин при T=90–95 °С и гидромодуле 1 : 10
Выявлены отличия в размерах областей когерентного рассеяния и параметрах кристаллографической ячейки образцов целлюлозы из хлопка и травянистых растений, а также между образцами из овса и люцерны, полученными в одинаковых условиях при одинаковом виде исходного сырья
Correlation coefficients are established between the values of the degree of ordering of the structure of cellulose samples from various plant raw materials, calculated using X-ray diffraction analysis and FT-IR spectroscopy, which make it possible to adequately compare all the known literature and experimental data
Summary
3% NaOH и 0.1% H2O2 в течение 60 мин при T=90–95 °С и гидромодуле 1 : 10. Хлопковую целлюлозу подвергали предварительному замачиванию в дистиллированной воде в течение нескольких часов для набухания и размягчения волокон целлюлозы. Гидролиз проводили при температуре 90 °С в течение 2 ч и постоянном перемешивании. Полученную дисперсию отмывали многократным центрифугированием при 4000 об./мин до pH=3.5. После чего полученную водную дисперсию частиц обрабатывали на УЗ-установке И100-6/4 (частота 20 кГц, мощность 0.5 кВт) в течение 10 мин. В работе [25] приведены электронные микрофотографии, дисперсный состав, а также некоторые физико-химические и структурные характеристики гидролизованных образцов целлюлозы, на основании которых полученные образцы были отнесены к МКЦ или НЦ Условия получения всех образцов целлюлозы, их шифры и средний размер частиц приведены в таблице 1.
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