(545b) Development of Low-Concentration Alkaline Treatment Method to Produce Thermally Stable Cellulose Nanofibrils (CNFs)

The thermal stability of cellulose nanofibrils (CNFs) can be improved by converting cellulose crystal structure from cellulose I to cellulose II using alkaline pretreatment method. The conventional pretreatment method requires 17.5% or higher concentrations of sodium hydroxide and large volume of water for neutralization to produce thermally stable, but interdigitated or aggregated CNFs. The main objective of this study was to develop a low concentration alkaline pretreatment method to produce thermally stable and highly dispersible CNFs. Cellulose nanofibrils with improved thermal stability were successfully prepared by treating cellulose powder with 2wt.% NaOH solution at low temperature (below 0 ), followed by mechanical disintegration through a French cell press with only ten passes. The thermally stable CNFs had an average diameter of 90 nm with the mean onset and maximum thermal decomposition temperature of 305 and 343 respectively, compared with those of 283 and 310 respectively, for the CNFs prepared without the NaOH treatment. The thermally stable CNFs can create new opportunities for the development of CNFs based packaging composites and high-end electronic applications.