Synthesis of low molar mass poly(acrylic) acid: comparison of the efficiency of two chain transfer agents

CÁCERES, GERARDO; GUTIERREZ, CAROLINA G; VEGA, JORGE R.; MINARI, ROQUE J.; GUGLIOTTA, LUIS M.

Florianopolis

Congreso; 12º Congresso Brasileiro de Polímeros; 2013

ABPOL

This work investigates the semibatch aqueous-solution polymerization of acrylic acid (AA) for the production of poly(acrylic acid) (PAA) of low molar masses. The synthesis procedure involves: a) an almost starved polymerization (i.e., an almost null concentration of AA along the reaction); and b) the use of two alternative water soluble transfer agents (CTA) for molar mass control [thioglycolic acid (TGA) or isopropyl alcohol (IPA)]. The synthesis strategy aims at controlling the molar masses and polydispersity of the produced PAA, while simultaneously minimizing the high refrigeration level typically required in the standard batch operation. An appropriate selection of the flow rate and concentration for both the CTA and AA allows the production of PAA with number-average molar masses ranging from 12,000 g/mol to 14,000 g/mol, and with a dispersity index close to 2.