摘要
We have studied the preparation of methylcellulose from annual cardoon and juvenile eucalyptus. The high cellulose and low lignin contents of these plants make them potential alternative resources for cellulose derivation. Their high quality pulps were obtained by the Impregnation Rapid Steam Pulping (IRSP) process and Total Chloride Free (TCF) bleaching sequences using hydrogen peroxide. The bleached pulp was methylated twice in an isopropanol slurry at 60 °C for 22 h after mercerisation in 40 % NaOH solution. Yields of water-soluble and alkali-soluble methylcellulose were determined by solvent extraction. Substitution patterns of methylcellulose were determined by 13C Nuclear Magnetic Resonance (NMR) spectroscopy. The intrinsic viscosities and solution properties of methylcellulose were measured in either 4 % NaOH solution or dimethyl sulphoxide (DMSO). This study shows that annual cardoon and juvenile eucalyptus can produce high-quality methylcellulose, which can be used as alternative resources for the production of methylcellulose.