The direct synthesis of poly(L-lactic acid) (PLLA) from an L-lactic acid oligomer has been performed in supercritical carbon dioxide (scCO(2)) using an esterification promoting agent, dicyclohexyldimethylcarbodiimide (DCC), and 4-dimethylaminopyridine (DMAP) as a catalyst. PLLA within M. of 13,500 g/mol was synthesised in 90% yield at 3500 psi and 80 degreesC after 24 h. The molecular weight distribution of the products was narrower than PLLA prepared with melt-solid phase polymerisation under conventional conditions. Both DCC and DMAP showed high solubility in scCO(2) (DCC: 7.6 wt% (1.63 X 10(-2) mol/mol CO2) at 80 degreesC, 3385 psi, DMAP: 4.5 wt% (1.62 X 10(-2) mol/mol CO2) at 80 degreesC, 3386 psi) and supercritical fluid extraction was found to be effective at removing excess DMAP and DCC after the polymerisation was complete. We show that DCC and DMAP are effective esterification promoting reagents with further applications for condensation polymerisations in scCO(2). (C) 2004 Elsevier Ltd. All rights reserved.