Characterization of Calcium Hydroxide-treated Zalacca Fibers for Improving Properties as Reinforcement for Composites

Chemical treatment is done to enhance characteristics of plant fibers and its interfacial compatibility with polymer matrix. Calcium hydroxide is an environmental-friendly alternative. This research aims to explore the influence of calcium hydroxide treatment on chemical, physical, thermal, morphological, and mechanical characteristics of zalacca fibers as reinforcements for composites. The time of treatment were varied for 24, 48, and 72 h. Fiber content analysis, XRD, FTIR, TGA-DTA, SEM, density, and single fiber tensile testing were performed. The percentage of cellulose was decreased meanwhile hemicellulose and lignin were increased. There was a decrease in crystallinity and crystallinity index after Ca(OH) 2 treatment. The treatment induced some chemical groups correlated to the slight increase of lignin and hemicellulose percentage. There was an improvement of thermal stability of the fiber up to 200°C. The observation using SEM revealed that there were cleaning and roughing effect on fiber surface. There was no significant change in fiber density due to the treatment. However, the tensile strength and elastic modulus were improved after Ca(OH) 2 treatment but the decline happened in a longer time of treatment. Accordingly, Ca(OH) 2 treatment up to 24 h is appropriate in enhancing the properties of zalacca fibers as composite reinforcements.