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Synthesis of Poly(L(+) Lactic Acid) by Polycondensation Method in Solution

  • Jian Zhang
  • Parakalan Krishnamachari
  • Jianzhong Lou
  • Abolghasem Shahbazi
Conference paper

Abstract

The disposal problem due to non-degradable petroleum-based plastics has raised the demand for biodegradable polymers. Poly(lactide) (PLA) is a biodegradable aliphatic polyester derived from 100% renewable resources, such as corn and sugar beets. Moreover, it has unique physical properties that make it useful in diverse applications including paper coating, fibers, films, and packaging. In this work, the results of the synthesis of high molar weight poly(L(+) lactic acid) (PLA) which is able to thermally crystallize have been described. The synthesis of poly(L(+) lactic acid) was carried out in a solution of p-xylene. Tin(II) chloride was used as catalysts in a quantity of 1.0 wt% calculated on the monomer. Polycondensation was carried out over a period from ten to over 20 h. The resulting poly(L(+) lactic acids) were characterized by FT-IR, DSC and the GPC. The molecular weight of PLLA reached as high as 26000. FTIR spectra of PLLA were analyzed to determine the configuration of the PLLA. The main byproduct of condensation polymerization is cyclo-polyester. The glass transition temperature of PLA after is 46.25°C. PLA after the recrystallization does not show glass transmission temperature because the crystallinity is more than 40%.

Keywords

Lactic Acid Azeotropic Distillation Condensation Polymerization Main Byproduct Direct Polycondensation 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Notes

Acknowledgments

Funding for this project was provided by the USDA; Mrs. Nicole Whiteman of NatureWorks provided technical advice.

References

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Copyright information

© Springer Science+Business Media, LLC 2009

Authors and Affiliations

  • Jian Zhang
    • 1
  • Parakalan Krishnamachari
    • 1
  • Jianzhong Lou
    • 1
  • Abolghasem Shahbazi
    • 2
  1. 1.Department of Chemical EngineeringNorth Carolina A&T State UniversityGreensboroUSA
  2. 2.Department of Natural Resources and Environmental DesignNorth Carolina A&T State UniversityGreensboroUSA

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