CO2-induced stereocomplex formation of stereoregular poly(methyl methacrylate) and microcellular foams

Tomohiro Mizumoto, Norio Sugimura, Masahiko Moritani, Yoshiyuki Sato, Hirokatsu Masuoka

Research output: Contribution to journalArticlepeer-review

60 Citations (Scopus)

Abstract

Crystalline stereocomplex formation of isotactic poly(methyl methacrylate) (it-PMMA) and syndiotactic poly(methyl methacrylate) (st-PMMA) induced by high-pressure CO2 at pressures in the 5-35 MPa range and at temperatures in the 30-110 °C range was demonstrated by means of differential scanning calorimetry (DSC) and wide-angle X-ray scattering (WAXS) investigations as a function of treatment pressure, temperature, and the it-PMMA/st-PMMA ratio. At a constant it-PMMA/st-PMMA ratio, the melting temperature of the stereocomplexes was shown to increase with increasing treatment pressure and temperature. The amount of the stereocomplex formed by high-pressure CO2 was found to be higher than that by thermal annealing in bulk. The heat of melting of the stereocomplex was the highest for the 1/2-1/1 it-PMMA/st-PMMA ratio. Compared with amorphous PMMA, the crystalline stereocomplex induced by high-pressure CO2 contributes to the superior morphology of the microcellular foams obtained. For the CO2-treated polymer, the average cell size decreases and the average cell density increases as the amount of the stereocomplex that was formed increases.

Original languageEnglish
Pages (from-to)6757-6763
Number of pages7
JournalMacromolecules
Volume33
Issue number18
DOIs
Publication statusPublished - 2000 Sep 5

ASJC Scopus subject areas

  • Organic Chemistry
  • Polymers and Plastics
  • Inorganic Chemistry
  • Materials Chemistry

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