ABSTRACT

Natural polymers with improved structure have been securing increasing value in the industry as they

are abundant, cheap, and biodegradable. Graft copolymerization is one of the effective ways to

enhance the properties of natural polymers. Starch based graft copolymers are becoming increasingly

important due to their remarkable adhesion, high water absorbency, and biodegradability. Methyl

methacrylate (MMA) grafted onto starch by using the ceric ammonium nitrate (CAN) as a redox

initiator in the presence of nitric acid in aqueous medium to form grafted copolymer (Starch-g-

PMMA) was investigated. The grafting reaction was carried out under stream of nitrogen gas. The

impact of different reaction parameters to achieve the highest percent grafting (%G) has been studied

by determining the initiator concentration, monomer concentration, time (hours), nitric acid

concentration, and polymerization temperature. The % G was found to be 97%. Evidence of grafting

was characterized and confirmed by Fourier transform infrared spectroscopy (FTIR). The peaks at

1736.70 cm-1 and 3449.78 cm-1 indicates that MMA has been successfully grafted to starch. %G was

found to be decreased at higher than 70°C, after 2 hours of reaction time, with an increase of MMA

monomer concentration, initiator concentration, and with HNO3 concentration. The highest percent

grafting was obtained at the parameters of 1 g starch, 70°C, 2 hours, 2 mmol CAN, 140 mmol MMA

and 0.4 mmol HNO3