Interactions between poly(acrylamide)-poly(itaconic acid) and cerium(IV)- Nitrilotriacetic acid redox pair in the synthesis of acrylamide and itaconic acid homo- And copolymers

Homopolymers of itaconic acid (PIA) and its copolymers with acrylamide (P(IA-AAm) were synthesized using ceric ammonium nitrate (NH₄)₂Ce(NO₃)₆ in combination with nitrilotriacetic acid (NTA) as redox initiator, and potassium persulphate at pH 1. The chain structures of the resulting products have been studied by FTIR spectroscopy. It is concluded from a comparison of spectroscopic results with gravimetric and viscometric data that the depressions in the yields and viscosity numbers in the case of Ce(IV)-NTA redox pair result from interactions between the constituents of the redox initiator and IA. Spectra of the insoluble and pale yellow precipitates, which are formed during the first 4h of the reaction, after addition of Ce(IV) solution to the NTA and NTA-IA homogeneous solutions, also indicate the presence of various oxidation products. Furthermore, it is observed that H-bonded homopolymer complex obtained from PAAm-PIA blends prepared from aqueous solutions containing equal unit moles of each polymer, contain both ordered and defective structures.