Cellulose nanocrystals obtained from office waste paper and their potential application in PET packing materials

Annually a tremendous amount of office waste paper (OWP) is discarded creating environmental pollution. Therefore, how to make this paper from waste to wealth and use it in new approaches have become a meaningful and challenging work. In this work, OWP being a cellulose rich biomass was employed for the production of cellulose nanocrystals (CNCs) by acid hydrolysis with different acid concentrations but without subjecting OWP to alkali and bleaching treatments. The testing results showed that CNCs prepared using sulfuric acid concentration of 59% with respect to OWP had the highest crystallinity and this concentration was the transition concentration for the production of opaque CNCs film with convoluted nanofibers to transparent one with orientated nanofibers. Besides, CNCs prepared using acid concentration of 65% coated on PET sheet not only had a better water vapor barrier property but also was on a par with the transparency of PET, which was hopeful to be used as coating materials in packaging materials.