Results and discussion
Table 1 showed the properties of PLLA synthesized in the TSE and the TSMR. It was found that the molecular weight and OP of PLLA polymers in both reactors increased firstly and then decreased with the increasing polymerization time, and the properties of PLLA synthesized in TSMR were better than those in TSE within the corresponding polymerization time [9]. This may be due to the higher mixing and heat removal efficiency of the static mixers in TSMR. Compared with L- lactide, the OP of PLLA in the TSMR decreased slightly, indicating that little racemization occurred. This result was similar to the reported experiments [12]. By comparison, the TSMR is more suitable than the TSE for preparation of PLLA with better properties.