Green adsorbent synthesis from orange mesocarp cellulose using graft copolymerization

Abstract

The potential of agricultural waste like orange (Citrus sinensis) mesocarp is yet to be explored. Thus, in this study the extraction of green adsorbent that will be renewable, low cost and environmentally friendly from orange mesocarp was examined. The extraction was done using alkali pretreatment method followed by bleaching process to obtain cellulose and dissolve the hemicellulose, lignin and other extractives. Then, graft copolymerisation of acrylamide onto the cellulose obtained was done using free radical initiation system. Grafting parameters were studied by varying the effects of initiator concentrations, monomer to cellulose ratio, temperature and time. Distilled water was used to extract the formed polyacrylamide (PAam) for 48 hours. And the characterization of the extracted and grafted cellulose samples was carried out by Fourier Transform Infrared Spectroscopy (FTIR). Orange mesocarp gave a cellulose average yield of 29.1%. The optimum grafting conditions were found to be 30OC at a time interval of 2 hours, ratio of monomer to cellulose being 3:1 and initiator concentration of 0.020M. The percentages of polymerization, graft and graft efficiency were 113.40, 86.83 and 45.90 respectively. Also, the absorbance peaks of the samples confirmed that grafting was effectively carried out on the cellulose backbone.