Chemically induced graft copolymerization of methacrylic acid onto low density polyethylene films using sodium bisulfite

A simple and inexpensive technique for preparation of membranes by chemically induced graft copolymerization of methacrylic acid (MAA) onto low-density polyethylene (PE) films using sodium bisulfite (SBS) initiator was developed. Several parameters affecting the grafting rate and yield, such as the concentration of aqueous monomer solutions (4-20%) and initiator (0.025-0.2 M/L), reaction temperature (50-70 degreesC), and within reaction times ranging from 1 to 6 h were studied. The results show that grafted films with 20% up to 500% graft were obtained under the synthesis conditions mentioned. Some selective properties of the grafted films (membranes), such as swelling behavior and mechanical properties were investigated. Also, the films were characterized by infrared (IR) spectroscopy, thermal gravimetric analysis (TGA), and scanning electron microscopy (SEM). Such prepared graft copolymers may be of great interest in some practical uses such as dialysis and ultrafiltration membranes and also for wastewater treatment from heavy and toxic metals.