Bibi, Gulnaz Jung, Youngmee Lim, Jong Choo Kim, Soo Hyun 2024-01-20T07:03:55Z 2024-01-20T07:03:55Z 2021-09-05 2015-05 0379-153X https://pubs.kist.re.kr/handle/201004/125500 Engineering the polylactide via stereocomplexation with supercritical fluid (SCF) technology paved way to fabricate polymers with enhanced thermal and mechanical properties. We aimed to establish a SCF medium with excellent solubility for PLA without any additional solvent/co-solvent. We, therefore, employed supercritical dimethyl ether to synthesize 100% stereocomplex polylactide from high molecular weight homopolymers with an excellent yield. The remarkable solubility of the homopolymers in dimethyl ether is the key for quick conversion to s-PLA. This study proves a rapid synthesis route of dry s-PLA powder with sc-DME at 250 bar, 70 degrees C and 1.5 h, which are reasonably achievable processing parameters compared to the conventional methods. The degree of stereocomplexation was evaluated under the effect of pressures, temperatures, times, homopolymer-concentrations and molecular weights. An increment in the degree of stereocomplexation was observed with increased temperature and pressure. Complete conversion to s-PLA was obtained for PLLA and PDLA with M-n similar to 200 kg.mol(-1) with a total homopolymer to total DME ratio of 6:100% w/w at prescribed reaction conditions. The degree of stereocomplexation was determined by DSC and confirmed by XRD. Considerable improvement in thermo-mechanical properties of s-PLA was observed. DSC and TGA analyses proved a 50 degrees C enhancement in melting transition and a high onset temperature for thermal degradation of s-PLA respectively. English POLYMER SOC KOREA ENANTIOMERIC POLY(LACTIC ACID)S PHASE-BEHAVIOR N-VINYLCARBAZOLE CARBON-DIOXIDE POLY(L-LACTIDE) POLYMERIZATION DEGRADATION MIXTURES POLYMERS STATE A Faster Approach to Stereocomplex Formation of High Molecular Weight Polylactide Using Supercritical Dimethyl Ether Article 10.7317/pk.2015.39.3.453 1 POLYMER-KOREA, v.39, no.3, pp.453 - 460 POLYMER-KOREA 39 3 453 460 scie scopus kci ART001991308 000355708300013 2-s2.0-84932100271 Polymer Science Polymer Science Article ENANTIOMERIC POLY(LACTIC ACID)S PHASE-BEHAVIOR N-VINYLCARBAZOLE CARBON-DIOXIDE POLY(L-LACTIDE) POLYMERIZATION DEGRADATION MIXTURES POLYMERS STATE fast stereocomplex dimethyl ether high molecular weight polylactides supercritical fluid technology