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Obtaining Nanocellulose from cellulose of Abaca tips

Abstract:

Abaca tips are currently considered waste, but they contain percentages of cellulose greater than 70 %, therefore they are ideal for obtaining cellulose nanocrystals (CNCs). The aim of this work was to obtain CNCs from cellulose pulp of abaca tips by acid hydrolysis. The first step was to get cellulose by pulping process with NaOH to remove lignin and other unwanted components. Subsequently, best reaction time and acid/cellulose ratio conditions were searched, to get CNCs with high crystallinity percentage and yield. Conditions used were acid hydrolysis with H2SO4 64 % (w/w) at a constant temperature of 45 °C with hydrolysis times of 15, 30, 45 and 60 min and acid/ cellulose ratios of 10, 11,5 and 13 mL/g. Best reaction time and acid/cellulose ratio were 45 min and 10 mL/g, which produced cellulose nanocrystals type Iβ with dimensions of: 4,69 nm of thickness and 300,90 nm of length, with a yield of 7,94 % and a crystallinity of 82,26 %. Shorter hydrolysis times (15 and 30 min) failed to obtain nanocrystals; while longer times (60 min), its managed to obtain CNCs, but with low yields (4.23%).