PRODUCING HYDROPHOBIC ALL-CELLULOSE COMPOSITE (ACC) VIA DIP-COATING METHOD
Cellulose is the most abundant natural polymer on earth that is widely used in bio-based composites due to its high mechanical properties, availability and biodegradability. All-cellulose composite (ACC) is known as a new class monocomponent of biocomposites because the use of cellulose-based component for matrix and reinforcing phases. However, a technical challenge for ACCs is observed due to the tendency for a higher water uptake, resulting in the deterioration of the mechanical properties. Therefore, this research will focus towards the improvement of the ACCs surface in order to increase the resistance to water absorption. Prior to characterisations, ACCs will be chemically treated using alkyl ketene dimer (AKD) via dip coating method. In this present study, the effect of two control factors, (i) AKD concentration (5, 7.5 and 10 wt.%), and (ii) heating temperature (80, and 100 oC), on treated ACC will be investigated using scanning electron microscopy (SEM), water absorption (WA) testing, and Fourier Transform Infrared (FTIR) spectroscopy. From FTIR analysis, it was observed that lactone ring of AKD was successfully attached on ACCs as observed by the decreasing spectrum range of OH stretching from 3420.7 cm-1 (untreated ACC) to 3342-3352 cm-1 (treated ACC). The presence of β-ketoester stretching was established within the wavenumber of 1723.5-1726.5 cm-1. Long fibrils and the presence of granular shape substances were observed on the surface of the treated ACC at the highest AKD concentration of 10 wt.%. A significant reduction of water absorption was observed from 140.3 to 40.0% upon completion of surface treatment for treated ACC produced with 10 wt.% AKD at 100˚C. Water absorption shows that ACC with higher AKD concentration helps reduce the penetration of water into the ACC.
Keywords - Solvent Infusion Process; All-Cellulose Composites; Surface Treatment; Water Absorption