A faster approach to stereocomplex formation of high molecular weight polylactide using supercritical dimethyl ether

Gulnaz Bibi, Youngmee Jung, Jong Choo Lim, Soo Hyun Kim

Research output: Contribution to journalArticle

7 Citations (Scopus)

Abstract

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 °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<inf>n</inf>∼200 kg-mol<sup>-1</sup> 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 °C enhancement in melting transition and a high onset temperature for thermal degradation of s-PLA respectively.

Original languageEnglish
Pages (from-to)453-460
Number of pages8
JournalPolymer (Korea)
Volume39
Issue number3
DOIs
Publication statusPublished - 2015 May 1

Keywords

  • Dimethyl ether
  • Fast stereocomplex
  • High molecular weight polylactides
  • Supercritical fluid technology

ASJC Scopus subject areas

  • Chemical Engineering(all)
  • Materials Chemistry
  • Polymers and Plastics

Fingerprint Dive into the research topics of 'A faster approach to stereocomplex formation of high molecular weight polylactide using supercritical dimethyl ether'. Together they form a unique fingerprint.

  • Cite this