Semibatch Aqueous Solution Polymerization of Acrylic Acid. Effect of Initiator, Chain Transfer Agent, and Reaction Temperature

CÁCERES MONTENEGRO, G; MINARI, R. J.; VEGA, J. R.; GUGLIOTTA, L. M.

Los Cocos, Córdoba

Simposio; V Simposio Argentino – Chileno de Polímeros - ARCHIPOL ‘09; 2009

Polymers containing acrylic acid (AA) are useful in a wide range of applications, depending on their molecular weight distribution (MWD) and degree of neutralization (Li and Schork, 2006). For instance, while the neutralized poly(acrylic acid): PAA of low molecular weight is used as sludge dispersant (Greenwald and Luskin, 1980), high molecular weight PAA is employed as paint thickener and flocculating agent. Finally, the cross-linked neutralized PAA is employed as superabsorbent material in baby diapers and feminine hygiene products. The PAA is mainly produced by free-radical aqueous-solution polymerization. Due to the extremely high AA reactivity, it results difficult to control the reaction temperature (Tr) and the MWD under batch conditions. Semibatch solution polymerization of AA with potassium persulfate (KPS) as initiator was able to control Tr = 60ºC by feeding AA along the reaction (Minari et al., 2007). Such strategy is further investigated in this work, with the aim of analyzing the effect of Tr, the KPS concentration, and the addition of a chain transfer agent (CTA) on both kinetics and MWD.