Effect of chemical modification on filler properties of pulverized castor seed (Ricinus communis) shell powder

Abstract

Effect of chemical modification on the filler properties of pulverized castor seed shell was investigated. Castor seed shells were obtained from Leventis Farms in Ososo, Edo State Nigeria. The shells were washed and dried to avoid sand and other forms of impurities. The dried shells were pulverized and separated into two portions. One portion was chemically modified with 20% NaOH concentration. The filler samples were characterized in terms of pH, bulk density, moisture content, lignin contents, cellulose contents, hemicellulose content, thermal stability, FTIR and SEM. The treated castor seed shell (TCSS) powder showed better characteristics when compared to the untreated sample (UCSS) in terms of pH (UCSS; 5.09 and TCSS; 8.15), bulk density (UCSS; 1.58g/cm3 and TCSS; 0.45 g/cm3), moisture content (UCSS; 5.24% and TCSS; 2.56%), lignin contents (UCSS; 17.78% and TCSS; 8.01%), cellulose content (UCSS; 15.43% and TCSS; 83.08%), hemicelluloses contents (UCSS; 12.23% and TCSS; 7.35%), thermal stability (UCSS; 2.87g/s and TCSS; 1.35g/s) and FTIR spectra respectively. The FTIR spectra showed the various functional groups present in the fibre. The TCSS showed removal of the hydroxyl groups present in the UCSS sample by purification increasing the TCSS hydrophobicity. The SEM micro-graph showed finer structure for the TCSS when compared to UCSS suggesting stronger and improved reinforcement with treatment.