Preparation and Properties of Nanocellulose from Peracetic Flax Pulp

The aim of the study was to obtain a pulp by ecology safer method from flax fibers and nanocellulose from organosolvent flax pulp (OFP) by acid hydrolysis and to investigate of its quality indexes. The OFP has been obtained by cooking in solution of peracetic acid. For obtaining of nanocellulose the hydrolysis of OFP by sulfuric acid with concentration of 43%, 50% and 64% at temperature 30 - 60°C during 30 and 90 min was carried out. The hydrolyzed OFP was washed by many times centrifugation at 8000 rev/min with distilled water until reaching neutral pH. Further ultrasonic treatment of the nanocellulose suspension from 30 to 60 minutes facilitated the formation of a nanocellulose gel, which was dried on Petri dishes to obtain transparent films. The optimal parameters of hydrolysis process are: concentration of sulfuric acid – 43%, temperature - 60°C duration 60 min. The obtained peracetic flax nanocellulose had degree of crystallinity – 62%, particles with diameter less than 60 nm, which is confirmed by AFM data; the transparency of received films was determined by electron absorption spectra and is more than 60%; the tensile strength up to 70 MPa and Young's module up to 9,0 GPa. The obtained nanocellulose had highest thermal stability compared to the OFP, which established by TGA. The method of obtaining peracetic flax nanocellulose allows obtaining a product with high quality indexes, which can be used in the production of different composite materials and optoelectronics. These predictors, however, need further work to validate reliability.