Cellulose nanocrystals and carboxymethyl cellulose from olive stones and their use to improve paper sheets properties

Abstract

Olive stones wastes were used to prepare cellulose nanocrystals (CNC) and carboxymethyl cellulose (CMC). Transmission electron microscopy images showed that the prepared nanocrystals had width and length of about 5–7 nm and 174–234 nm, respectively. Mixtures containing CMC and CNC in water were prepared and the effect of CNC ratio (from 2.5–10 wt.% based on CMC) on viscosity of CMC solution was studied. Films casted from CMC/CNC mixtures were characterised regarding their crystallinity, tensile strength, and dynamic mechanical thermal properties. In addition, the prepared mixtures were used for coating of paper sheets and the effect of coating on mechanical properties (breaking length and tear factor), water absorption, and air permeability of paper sheets was studied. Presence of CNC in the coating mixtures resulted in improving mechanical properties and decreasing water absorption and air permeability of paper sheets as compared to paper sheets coated with neat CMC coating mixture.