Stereoregular high polymers of poly(L-lactic acid) (PLLA) (M-w 1.2 x 10(5), isotacticity 96.0%) and poly(D-lactic acid) (PDLA) (M, 1.0 x 10(5), isotacticity 98.6%) were successfully synthesized via melt/solid polycondensation (MP/SSP) using a biogenic catalyst creatinine (CR). The follow-up monitor of the polycondensation products with C-13 NMR technique revealed that the polymerization of MP/SSP proceeded in a stereochemical controlled way throughout the whole process as evidenced by the constant high values of isotacticity (97.8-99.4%) of produced polymers. Thermogravimetric analysis demonstrated that the decomposition temperatures (T-d,init 324.3 degrees C, Td, (5%) 347.0 degrees C, Td, (max) 400.2 degrees C) of PLLA synthesized with catalyst CR are over 100 degrees C above those of PLEA synthesized with catalyst SnCl2-2H2O. (C) 2014 Elsevier Ltd. All rights reserved.