Teflon scrap based cation exchanger by radiation grafting: Process parameter standardization and characterization

High-energy gamma radiation from 60Co-gamma radiation source has been used to covalently link acrylic acid to teflon by mutual radiation grafting technique. Effect of various experimental parameters viz, dose, dose rate, monomer concentration, backbone thickness effect of additives on grafting extent was investigated in order to optimize the conditions for grafting acrylic acid onto teflon to optimum levels. The grafting extent decreased with increasing dose rate and thickness of the substrate while it increased with concentration of acrylic acid and optimum concentration of Mohr's salt. The grafted product was characterized for grafting yield, surface morphology, bulk morphology, and crystallinity change. The SEM studies indicate significant difference in bulk and interface due to change in thickness of the teflon backbone. Dynamic contact angle measurement studies of the grafted and radiation treated teflon showed that initial grafting as well as radiation treatment of teflon enhances its hydrophilicity. (C) 2011 American Institute of Chemical Engineers Environ Prog, 2012