CELLULOSE NANOCRYSTALS: SYNTHESIS, CHARACTERISTICS AND EFFECT ON HYDROXYPROPYL METHYLCELLULOSE-BASED COMPOSITE FILMS AND COATINGS

Abstract

This study aimed to synthesize, determine characteristics of cellulose nanocrystals such as morphology, size particle, zeta potential, Fourier transform infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The study also evaluated effect of concentration of added cellulose nanocrystals to hydroxypropyl methylcellulose-base films and coatings containing carnauba Nano emulsion and chitosan nanoparticles. Results showed the shape and size of the nanoparticle generally depend on hydrolysis condition of microcrystalline cellulose. Cellulose nanocrystals obtained from processing hydrolyzed microcrystalline cellulose in range from 47 wt. % to 55 wt. % had length range of from 160 to 196 nm and diameter from 9 to 11 nm. Cellulose nanocrystals were added into nanocomposite HPMC that incorporated with both of carnauba Nano emulsion and chitosan nanoparticles with concentration of cellulose nanocrystals at levels: 0.2, 0.5, 0.8 and 1.1 %. Scanning electron microscopy (SEM) images revealed that nanocomposite films become more compact and dense due to the cellulose nanocrystals occupy empty spaces of porous of matrix nanocomposite HPMC increasing the collapse of the pores in the films. The concentration of cellulose nanocrystals at 0.5 % was added to Nanocomposite HPMC including both of carnauba nano emulsion and chitosan nanoparticles improved the physical strength of film with the best quality compared with other films as: film solubility was raised up 16.65 %, film drying time is faster than others (51.33 minutes). Assessement of the effect of cellulose nanocrystals added into the nanocomposite films coated on fruit bananas showed that respiration of bananas were reduced from 57.08 ml CO2/kg.h to 30.17 ml CO2/kg.h; weight loss was declined from 4.0 % to 1.82 % thanks to the limitation of the films gas and moisture permeability.