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Miscanthus x giganteus stalks were used to make organosolvent pulp and nanocellulose. The organosolvent miscanthus pulp (OMP) was obtained through thermal treatment in the mixture of glacial acetic acid and hydrogen peroxide at the first stage and the alkaline treatment at the second stage. Hydrolysis of the never-dried OМP was carried out by a solution of sulfuric acid with concentrations of 43% and 50% and followed by ultrasound treatment. Structural changes and the crystallinity index of OMP and nanocellulose were studied by SEM and FTIR methods. X-ray diffraction analysis confirmed an increase in the crystallinity of OMP and nanocellulose as a result of thermochemical treatment. We show that nanocellulose has a density of up to 1.6 g/cm3, transparency up to 82%, and a crystallinity index of 76.5%. The AFM method showed that the particles of nanocellulose have a diameter in the range from 10 to 20 nm. A thermogravimetric analysis confirmed that nanocellulose films have a denser structure and lower mass loss in the temperature range of 320–440°C compared to OMP. The obtained nanocellulose films have high tensile strength up to 195 MPa. The nanocellulose obtained from OMP exhibits the improved properties for the preparation of new nanocomposite materials.

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Досліджено різні стадії обробки волокон конопель у процесі одержання мікрокристалічної целюлози. Визначено оптимальні умови проведення лужної екстракції волокон конопель, органосольвентного варіння, хелатування і гідролізу целюлози. Встановлено, що проведення вказаних стадій обробки за оптимальних значень технологічних параметрів призводить до отримання мікрокристалічної целюлози, яка за вмістом сульфатної золи і ступенем полімеризації відповідає вимогам стандарту Ключові слова: мікрокристалічна целюлоза, волокно конопель, екстракція, гідроліз, рентгенівська дифракція, термогравіметричний аналіз Исследованы различные стадии обработки волокон конопли в процессе получения микрокристаллической целлюлозы. Определены оптимальные условия проведения щелочной экстракции волокон конопли, органосольвентной варки, хелатирования и гидролиза целлюлозы. Установлено, что проведение указанных стадий обработки при оптимальных значениях технологических параметров приводит к получению микрокристаллической целлюлозы, которая по содержанию сульфатной золы и степенью полимеризации соответствует требованиям стандарта Ключевые слова: микрокристаллическая целлюлоза, волокно конопли, экстракция, гидролиз, рентгеновская дифракция, термогравиметрический анализ UDC 676.166+661.

We present the study of the preparation of pulp and nanocellulose from Miscanthus × giganteus to improve the quality of the paper for bags. The organosolv miscanthus pulp (OMP) was prepared by the environmentally friendly organosolv method-cooking in a solution of peracetic acid at the first stage and the alkaline treatment at the second stage. Nanocellulose was obtained by hydrolysis of never-dried OMP and subsequent ultrasonic treatment. Structural changes and crystallinity index of OMP and nanocellulose were studied by SEM and FTIR methods. X-ray diffraction analysis confirmed an increase in the crystallinity of OMP and nanocellulose as a result of thermochemical treatment. The nanocellulose had a density of up to 1.6 g/cm 3 , transparency up to 82%, a crystallinity index of 76.5%, and tensile strength up to 195 MPa. The AFM showed that the particles of nanocellulose have a diameter in the range from 10 to 20 nm. A TGA analysis confirmed that nanocellulose films have a denser structure and lower mass loss in the temperature range 320-440 °C compared to OMP. We established the positive effect of nanocellulose application on the physical and mechanical properties of paper for bags. The application of nanocellulose allows replacing synthetic reinforcing materials and more expensive sulfate unbleached pulp with waste paper in the production of paper and cardboard.