LAUSR

Abstract Persulfate initiated free radical homopolymerization of itaconic acid in aqueous media has been investigated at 65 °C. The research was focused on the elucidation of the chemical structure of low-molecular-weight side products and itaconic oligomers separated from polymeric fraction by dialysis (cut-off of 1000 Da). Nuclear magnetic resonance (NMR) 1H, 13C, 1H–13C me-HSQC and 1H–13C HMBC experiments and direct infusion electrospray ionization mass spectrometry (ESI-MS) operated in the negative ion mode have been combined to investigate the low-molecular fraction. It was found that 2-hydroxyparaconic and itatartaric acid are the primary oxidation products formed during free radical polymerization of itaconic acid. Besides, ESI-MS analysis revealed sulfate, hydroxyl and lactone terminal groups resulted from disproportionation, combination and transfer processes. Kinetics studies using Raman spectrometry in initiator range of 0.07–0.32 mol/L and for monomer concentration between 1.32 and 2.63 mol/L indicated non-classical dependency both polymerization rate and initiator decomposition rate on monomer and initiator concentration.