Effect of acid hydrolyses on properties of cellulose/poly furfural alcohol (PFA) composites from maize stalk

The study investigated morphology and thermal properties of cellulose/poly furfural alcohol (PFA) composites prepared from maize stalk through acid mixtures. The cellulose nanocrystals (CNCs) were extracted from maize stalk via acid hydrolysis using mixtures of various acids. The prepared CNCs were encapsulated in a PFA matrix via in situ polymerization process using p-toluene sulfonic acid as catalyst. The properties of untreated maize stalk, cellulose and their nanocomposites were analysed by scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier transmission infrared (FTIR) and thermogravimetric analysis (TGA). The crystallinity of maize stalk was generally increased after an acid hydrolysis dominated by H2SO4/HNO3 and H2SO4/HCl. The same trend was observed from TGA, except that H2SO4/H3PO4 and H2SO4/HClO4 dominated thermal stability trailed by H2SO4 hydrolysed CNC nanocomposite. The surface breakage of fibers observed in SEM images was depended on the strength of acids used to hydrolysed the CNC. There was also evidence of aggregation and cracked PFA surface with addition of acid hydrolysed CNCs, dependent on the acids strength. The H2SO4/HClO4 hydrolysed CNC/PFA displayed a fairly good dispersion of CNCs in the PFA matrix with no surface breakage.