Fabrication of biocomposite materials with polycaprolactone and activated carbon extracted from agricultural waste

Abstract

In this study, activated carbon was extracted from a source of agricultural waste (wheat straw) through a chemical activation process and blended with polycaprolactone (PCL) to fabricate new biocomposite materials. Three distinct types of activated carbon, designated as C1, C2, and C3 were obtained by varying the ratio of the activation agent and wheat straw and different drying conditions. Through a comprehensive array of analytical techniques, including FTIR, XRD, BET, EDS, and FE-SEM, we determined the optimal experimental method for extracting activated carbon from wheat straw and identified the most effective type of activated carbon (C3). Based on these analyses, C3 exhibits the highest carbon content, the greatest specific surface area (386.47 m2/g), and the highest total pore volume (0.2596 cm3/g). By blending polycaprolactone with the optimal activated carbon (at concentrations of 1, 3, and 5 wt%), biocomposite samples were fabricated. The results of FTIR indicate that the biocomposite materials containing 1, 3, and 5 wt% of activated carbon exhibit no disturbing peaks. However, the sample PCL-C,1 wt%, shows significant increases in the intensity of observed peaks. XRD analyses of the fabricated biocomposite samples illustrate that the sample containing 1 wt% of activated carbon has a greater tendency for crystallization compared to the other samples. Morphological analysis of the biocomposites and the dispersion of carbon particles within them demonstrate the least amount of agglomeration in the sample with an activated carbon concentration of 1 wt%. Upon assessing the mechanical properties of biocomposites, the same sample (1 wt% of C3) demonstrates more favorable characteristics than the other samples. Furthermore, a contact angle test was conducted to gauge the biocomposite hydrophilicity, revealing a 7 degree increase in contact angle for the sample with an activated carbon concentration of 1 wt% compared to the pure PCL sample. Thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were used to examine the weight loss, degradation temperature, melting temperature, and glass transition temperature of the synthesized materials. These analyses indicate a marginal augmentation in both melting and glass transition temperatures for the sample with an activated carbon concentration of 1 wt%.