Polymerization of maleic acid and itaconic acid studied by FT‐Raman spectroscopy

In this research, we used a new redox free radical initiation system consisting of potassium persulfate (K 2 S 2 O 8 ) and sodium hypophosphite (NaH 2 PO 2 ). In the presence of NaH 2 PO 2 , the thermal decomposition of K 2 S 2 O 8 is accelerated, and the temperature required for the formation of free radical is reduced. We polymerized maleic acid (MA) using the K 2 S 2 O 8 /NaH 2 PO 2 initiation system in an aqueous solution, and monitored the polymerization process with FT‐Raman spectroscopy. The Raman spectroscopy data indicate the formation of a saturated carboxylic acid with the disappearance of the characteristic bands of MA as the thermal decomposition of K 2 S 2 O 8 progresses, thus indicating the formation of poly(maleic acid) (PMA). We also found that itaconic acid (IA) polymerizes in the presence of the new initiation system. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 223–228, 2001