HYDROLYSIS OF POLY(ACRYLAMIDE) - STARCH GRAFT COPOLYMER

Poly(acrylamide)-starch graft copolymer was treated independently with sodium hydroxide and different acid solutions, The different acids in clude phosphoric, hydrochloric and sulphuric acid. The treatment was c arried out under a variety of conditions including sodium hydroxide co ncentration, time and duration of hydrolysis as well as type of acid u sed, The extent of hydrolysis was assessed by estimating amide and car boxyl content as well as the acrylate and starch content before and af ter treatment. It was found that the increment in carboxyl content is equal to the decrement in amide on using sodium hydroxide concentratio n up to 1N, while using higher concentrations than 1N lead to differen ces in formed carboxyl and decreased amide groups. The magnitude of th is difference depends on sodium hydroxide concentration as well as tem perature and duration of hydrolysis. The maximum value of carboxyl con tent obtained was 593 m . eq/100g sample. The acidic treatment of the starch copolymer does not affect the conversion of amide groups to car boxyl groups and the lonely effect was hydrolysis of starch component of tile copolymer. Evaluation of the alkali treated copolymer as catio n exchanger was carried out. The absorption efficiency % of different cations depends on the associated anions and follow the order: Cu2+ > Zn2+ > Co2+ > Mg2+.