Aqueous-Solution Polymerization of Acrylic Acid. A Semicontinuous Strategy for Controlling the Molar Masses and the Reaction Temperature

R. MINARI, C. GUTIERREZ, V. GONZALEZ, M. YOSSEN, M. BRANDOLINI, J. VEGA, L. GUGLIOTTA

Prague, Czech Republic

Congreso; 18th International Congress of Chemical and Process Engineering CHISA 2008; 2008

Polymers containing acrylic acid (AA) are useful in a wide range of applications, depending on their molar mass distribution (MMD) and the degree of neutralization. For instance, while the neutralized poly(acrylic acid) (PAA) of low molar mass is used as a sludge dispersant, the high molar mass PAA is employed as a paint thickener and a flocculating agent. Finally, the cross-linked neutralized PAA is utilized as superabsorbent material in baby diapers and feminine hygiene products. The PAA is mainly produced by free-radical aqueoussolution polymerization. Due to the extremely high AA consumption rate, the batch reaction is highly exothermic; and therefore it is difficult to control the reaction temperature (Tr) and the polymer quality. In this work, a semicontinuous strategy is proposed for simultaneously controlling the average molar masses and Tr under isothermal and safe conditions.