Morphological, thermal, and mechanical properties of starch biocomposite films reinforced by cellulose nanocrystals from rice husks

Abstract

A series of glycerol-plasticized starch composites reinforced by rice-husk cellulose nanocrystals was successfully fabricated through the solution casting technique. The rice husks must undergo alkali treatment, bleaching, and sulphuric acid hydrolysis before cellulose nanocrystals can be produced. The cellulose nanocrystal content used as filler was varied from 0 to 10 wt%. The thermal stability of the composite were analysed by thermogravimetric analysis (TGA) and derivative thermogravimetry (DTG). The starch biocomposite films reinforced with rice-husk cellulose nanocrystals showed improved tensile strengths and tensile moduli. Transmission electron microscopy (TEM) was used to determine the diameter and length distribution of the cellulose nanocrystals. Field emission scanning electron microscopy (FESEM) showed that the cellulose nanocrystals (CNCs) were well distributed in the matrix. At the optimum 6% filler loading, the cellulose nanocrystals exhibited a higher reinforcing efficiency in the plasticized starch biocomposites than at any other filler loading.