Effect of sulfuric acid reaction time on the properties and behavior of cellulose nanocrystals from Cocos nucifera var-Aurantiaca peduncle’s cellulose microfibers

Abstract

Cocos nucifera var-Aurantiaca peduncles are agricultural waste material discarded by harvesters after taking the fruit. The isolation of Cellulose NanoCrystals (CNCs) from peduncle derived Cellulose MicroFibers (CMFs) is an effective alternative approach to recover the waste. In the present work, CNCs were isolated by using sulfuric acid hydrolysis (64 wt%) with different hydrolysis time at constant temperature of 45 °C. The effect of hydrolysis time (30, 45, 60 min) on the crystalline index, colloidal stability of suspension, yield, thermal stability, morphology, chemical and elemental composition of CNCs are evaluated. The characterization of isolated CNCs with 60 min (CNCs/60 min) hydrolysis time provides high crystalline index (%), yield (%) with good colloidal stability and appearance in well dispersed uniform rod-like structure with a width of 12 ± 1.2 nm and length of 200 ± 20 nm. The effect of reinforcement of CNCs/60 min in agar matrix whose tensile strength is increased by 37% when 6 wt% of CNCs/60 min was loaded into the matrix.