Preparation and properties of technical cellulose from hogweed by the oxidative-organosolvent method
Hogweed multiplies rapidly and gains a large volume of phytomass during the growing season, which allows us to consider the mature biomass of hogweed as a raw material for cellulose production. The aim of the work is to obtain cellulose from lignified stems of hogweed by an oxidative-organosolvent method and study its properties. Raw materials in the form of stems harvested in August contain less lignin, more cellulose and minerals, compared to raw materials harvested in September. The component composition of raw materials: the mass fraction of lignin is 21.9%, cellulose is 46.4% of the absolutely dry raw materials. Depending on the conditions, cellulose with a yield of 49.5-49.7% was obtained by redox-organosolvent cooking with preliminary alkaline treatment % of absolutely dry raw materials, the mass fraction of lignin is 3.9-4.3% of the mass of absolutely dry cellulose, whiteness 72.0-80.2%. The best indicators for physical and mechanical properties are cellulose obtained at a consumption of 0.8 g/g of equilibrium peroxyacetic acid and with a duration of alkaline treatment of 90 minutes. The analysis of cellulose showed that it is possible to obtain cellulose from hogweed that is comparable in characteristics to GOST 28172-89. The anatomical elements of cellulose contain bast fibers, parenchymal cells and vessels. The average fiber length is 0.70 mm, and the average fiber width is 20.4 microns. According to the fractional composition and fiber sizes, the resulting cellulose should be attributed to short-fiber semi-finished products.