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

R.J. MINARI; C.G. GUTIERREZ; V.D.G. GONZALEZ; M.M. YOSSEN; M.C. BRANDOLINI; J.R. VEGA; L.M. GUGLIOTTA

Praga

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

The isothermal semicontinuous polymerization of AA was experimentally investigated for producing PAA at complete global conversion, under safety condition and with controlled molar masses. The proposed strategies mainly consist in feeding the AA and/or the initiator components at constant feed rates along the reaction. When potassium persulfate (KPS) was used as initiator at 60°C, a medium-molar mass PAA grade with Mn= 40000 g/mol was adequately produced. When the reaction was carried out at 45°C, and the components of the couple redox KPS / sodium metabisulfite (SMB) were independently fed at constant flow rates, a low-molar mass PAA grade with Mn= 4000 g/mol was successfully synthesized. The proposed strategies were first implemented in a laboratory scale reactor, and then tested in a pilot scale reactor (under unrestricted access of O2). The strategies show to be robust and allow to work under safe and reproducible conditions.