Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Original Article
  • Published:

Formation of PLA stereocomplex crystals during melt-blending of asymmetric PLLA/PDLA/PMMA blends of varying miscibility

Abstract

Polylactide (PLA) enantiomers of poly(l-lactide) (PLLA) and poly(d-lactide) (PDLA) were melt-blended with poly(methyl methacrylate) (PMMA) and compression-molded at a temperature between the melting points of PLA homocrystals (Tm,HC) and stereocomplex (SC) crystals (Tm,SC), causing the selective formation of SC crystallites. The degree of crystallinity of the SC crystals (χc,SC) did not change with the PMMA weight fraction but did vary with changes in the weight ratio of PLLA to PDLA. From differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA) measurements, the miscibility of PLA and PMMA was confirmed, but the formation of SC crystals during melt-blending induced phase separation into PLA-rich and PMMA-rich phases. The formation of homocrystals was hindered by increases in the weight fraction of PMMA and χc,SC. The thermal and viscoelastic properties of the PLLA/PDLA/PMMA blends were also affected by the PMMA weight fraction and χc,SC. According to the DMA results, the storage modulus of the ternary blends with higher χc,SC values showed a gentler decrease at the glass transition temperature; the ternary blends also exhibited a higher storage modulus than the PLLA/PMMA blends at high temperatures near Tm,HC.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8
Fig. 9

Similar content being viewed by others

References

  1. De Santis P, Kovacs AJ. Molecular conformation of poly(s-lactic acid). Biopolymers. 1968;6:299–306.

    Article  Google Scholar 

  2. Sasaki S, Asakura T. Helix distortion and crystal structure of the α-Form of poly(l-lactide). Macromolecules. 2003;36:8385–90.

    Article  CAS  Google Scholar 

  3. Zhang J, Duan Y, Sato H, Tsuji H, Noda I, Yan S, et al. Crystal modifications and thermal behavior of poly(l-lactic acid) revealed by infrared spectroscopy. Macromolecules. 2005;38:8012–21.

    Article  CAS  Google Scholar 

  4. Marubayashi H, Akaishi S, Akasaka S, Asai S, Sumita M. Crystalline structure and morphology of poly(l-lactide) formed under high-pressure CO2. Macromolecules. 2008;41:9192–203.

    Article  CAS  Google Scholar 

  5. Eling B, Gogolewski S, Pennings AJ. Biodegradable materials of poly(l-lactic acid): 1. Melt-spun and solution-spun fibres. Polymer. 1982;23:1587–93.

    Article  CAS  Google Scholar 

  6. Puiggali J, Ikada Y, Tsuji H, Cartier H, Okihara T, Lotz B. The frustrated structure of poly(l-lactide). Polymer. 2000;41:8921–31.

    Article  CAS  Google Scholar 

  7. Cartier L, Okihara T, Ikada Y, Tsuji H, Puiggali J, Lotz B. Epitaxial crystallization and crystalline polymorphism of polylactides. Polymer. 2000;41:8909–19.

    Article  CAS  Google Scholar 

  8. Okihara T, Tsuji M, Kawaguchi A, Katayama K, Tsuji H, Hyon S-H, et al. Crystal structure of stereocomplex of poly(L-lactide) and poly(D-lactide). J Macromol Sci Phys-B. 1991;30:119–40.

    Article  CAS  Google Scholar 

  9. Tsuji H, Ikada Y. Crystallization from the melt of poly(lactide)s with different optical purities and their blends. Macromol Chem Phys. 1996;197:3483–99.

    Article  CAS  Google Scholar 

  10. Shi X, Jing Z, Zhang G. Influence of PLA stereocomplex crystals and thermal treatment temperature on the rheology and crystallization behavior of asymmetric poly(L-lactide)/poly(D-lactide) blends. J Polym Res. 2018;25:71–86.

    Article  Google Scholar 

  11. Wei XF, Bao RY, Cao ZQ, Yang W, Xie BH, Yang MB. Stereocomplex crystallite network in asymmetric PLLA/PDLA blends: formation, structure, and confining effect on the crystallization rate of homocrystallites. Macromolecules. 2014;47:1439–48.

    Article  CAS  Google Scholar 

  12. Bao RY, Yang W, Jiang WR, Liu ZY, Xie BH, Yang MB, et al. Stereocomplex formation of high-molecular-weight polylactide: a low temperature approach. Polymer. 2012;53:5449–54.

    Article  CAS  Google Scholar 

  13. Pan P, Han L, Bao J, Xie Q, Shan G, Bao Y. Competitive stereocomplexation, homocrystallization, and polymorphic crystalline transition in poly(l-lactic acid)/poly(d-lactic acid) racemic blends: molecular weight effects. J Phys Chem B. 2015;119:6462–70.

    Article  CAS  Google Scholar 

  14. Tsuji H, Ikada Y. Stereocomplex formation between enantiomeric poly(lactic acids). XI. Mechanical properties and morphology of solution-cast films. Polymer. 1993;26:6918–26.

    CAS  Google Scholar 

  15. Bao RY, Yang W, Jiang WR, Liu ZY, Xie BH, Yang MB. Polymorphism of racemic poly(l-lactide)/poly(d-lactide) blend: effect of melt and cold crystallization. J Phys Chem B. 2013;117:3667–74.

    Article  CAS  Google Scholar 

  16. López-Rodríguez N, Martínez de Arenaza I, Meaurio E, Sarasua JR. Efficient stereocomplex crystallization in enantiomeric blends of high molecular weight polylactides. ACS Adv 2015;44:34525–34.

    Google Scholar 

  17. Cedric S, Jean-Marie R, Philippe D. PLLA/PMMA blends: a shear-induced miscibility with tunable morphologies and properties? Polymer. 2013;54:3931–9.

    Article  Google Scholar 

  18. Shirahase T, Komatsu Y, Tominaga Y, Asai S, Sumita M. Miscibility and hydrolytic degradation in alkaline solution of poly(L-lactide) and poly(methyl methacrylate) blends. Polymer. 2006;47:4839–44.

    Article  CAS  Google Scholar 

  19. Hirota S, Sato T, Tominaga Y, Asai S, Sumita M. The effect of high-pressure carbon dioxide treatment on the crystallization behavior and mechanical properties of poly(L-lactic acid)/poly(methyl methacrylate) blends. Polymer. 2006;47:3954–60.

    Article  CAS  Google Scholar 

  20. Samuel C, Cayuela J, Barakat I, Müller AJ, Raquez J-M, Dubois P. Stereocomplexation of polylactide enhanced by poly(methyl methacrylate): improved processability and thermomechanical properties of stereocomplexable polylactide-based materials. ACS Appl Mater Interfaces. 2013;5:11797–807.

    Article  CAS  Google Scholar 

  21. Liu T, Xiang F, Qi X, Yang W, Huang R, Fu Q. Optically transparent poly(methyl methacrylate) with largely enhanced mechanical and shape memory properties via in-situ formation of polylactide stereocomplex in the matrix. Polymer. 2017;126:231–9.

    Article  CAS  Google Scholar 

  22. Bao RY, Yang W, Liu ZY, Xie BH, Yang MB. Polymorphism of a high-molecular-weight racemic poly(L-lactide)/poly(D-lactide) blend: effect of melt blending with poly(methyl methacrylate). RSC Adv. 2015;5:19058–66.

    Article  CAS  Google Scholar 

  23. Dong Q, Bian Y, Li Y, Han C, Dong L. Miscibility and crystallization behaviors of stereocomplex-type poly(L- and D-lactide)/poly(methyl methacrylate) blends. J Therm Anal Calor. 2014;118:359–67.

    Article  CAS  Google Scholar 

  24. Tsuji H. Poly(lactide) stereocomplexes: formation, structure, properties, degradation, and applications. Macromol Biosci. 2005;5:569–97.

    Article  CAS  Google Scholar 

  25. Tsuji H, Horii F, Nakagawa M, Ikada Y, Odani H, Kitamura R. Stereocomplex formation between enantiomeric poly(lactic acid)s. 7. Phase structure of the stereocomplex crystallized from a dilute acetonitrile solution as studied by high-resolution solid-state carbon-13 NMR spectroscopy. Macromolecules. 1992;25:4114–8.

    Article  CAS  Google Scholar 

  26. Fischer EW, Sterzel HJ, Wegner GK. Investigation of the structure of solution grown crystals of lactide copolymers by means of chemical reactions. Kolloid-Z Z Polym. 1973;251:980–90.

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We would like to thank Editage (www.editage.jp) for English language editing.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Shigeo Asai.

Ethics declarations

Conflict of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher’s note: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Iguchi, Y., Akasaka, S. & Asai, S. Formation of PLA stereocomplex crystals during melt-blending of asymmetric PLLA/PDLA/PMMA blends of varying miscibility. Polym J 52, 225–235 (2020). https://doi.org/10.1038/s41428-019-0256-6

Download citation

  • Received:

  • Revised:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41428-019-0256-6

Search

Quick links