Synthesis and Characterization of Starch‐N‐methylol Acrylamide‐Methacrylic Acid Cation Exchange Composites

Starch‐N‐methylol acrylamide methacrylic acid cation exchange composites were synthesized by polymerizing of highly concentrated aqueous mixtures of methacrylic acid and N‐methylol acrylamide with starch using ammonium peroxydisulphate, as an initiator, alone and with different reductants, viz. sodium thiosulphate, sodium pyrosulphite and glucose. Sodium thiosulphate proved to be the best reductant that can produce the composite at the lowest solidification time with the highest insoluble yield and carboxyl content. Factors affecting the process such as temperature, redox system concentration and concentrations of monomers were reported. Four kinds of cation exchange composites, of different nitrogen and carboxyl contents, were prepared. These composites were characterized by potentio‐metric titrations, water solubility and swellability, as well as durability to use.