Graft Copolymerization of Methyl Methacrylate onto Starch and Triethylamino Starch

Abstract

The effects of polymerization conditions were investigated on the graft copolymerization of methyl methacrylate (MMA) initiated by ceric ammonium nitrate on starch and triethylamino starch (TEAS) in aqueous medja.
Under the conditions such as starch or TEAS concentration of 2 %, HNO₃ concentration of 0.014 N, polymerization temperature of 50°C and reaction time of 2 hrs., the total conversion (T), the percentage of grafting (P) and the graft efficiency (E) became higher with increasing initiator concentration and lower with increasing monomer concentration (4∼17 %).
The polymerization temperature (30∼60°C) appeared to be most suitable at 50°C from the results of (P). On the polymerization time, (T) and (P) became higher with increasing the time. (P) and (E) showed maximum values at some concentration of starch or TEAS respectively, and similarly with HNO₃ concentration also. The value of (P) became larger at the region of high HNO₃ concentration with low concentration of initiator, whereas in the case of low concentration of HNO₃ with high concentration of initiator.
(P) and (E) of the aqueous suspension system of starch or TEAS were generally higher than that of the aqueous solution system, and the results of the starch system were larger than that of the TEAS system.
The graft copolymer was quite insoluble in boiling water, methanol and acetone, but dissolved in dimethylsulfoxide. Therefore, the cross-linked structure seemes to be absent in this copolymer.