Refractive Index Engineering as a Novel Strategy toward Highly Transparent and Tough Sustainable Polymer Blends

Abstract

High transparency and toughness are prerequisites for sustainable polymers if they are to find wide application as alternatives to petroleum-based polymers. However, the utility of sustainable polymers such as commercially available polylactide (PLA) is limited by their inherent brittleness and high cost. Unfortunately, toughening PLA-based materials via cost-effective blending strategies without sacrificing transparency remains a challenge. Herein, we report a novel strategy involving active refractive index matching for creation of highly transparent and tough PLA blends. Specifically, we engineered the refractive index of a promising renewable poly(epichlorohydrin-co-ethylene oxide) elastomer by introducing polar ionic moieties via a simple chemical method, and we blended the resulting ionomers with PLA. The best blend showed an impact strength of > 80 kJ/m2, an elongation at break of 400%, and high transparency (90%). These characteristics are of great importance for potential applications such as packaging. Our strategy offers a versatile new way to prepare high-performance sustainable polymer materials with excellent transparency.

This is a preview of subscription content, log in to check access.

References

  1. 1

    Loste, J.; Lopez-Cuesta, J. M.; Billon, L.; Garay, H.; Save, M. Transparent polymer nanocomposites: an overview on their synthesis and advanced properties. Prog. Polym. Sci.2019, 89, 133–158.

    CAS  Google Scholar 

  2. 2

    Groh, K. J.; Backhaus, T.; Carney-Almroth, B.; Geueke, B.; Inostroza, P. A.; Lennquist, A.; Leslie, H. A.; Maffini, M.; Slunge, D.; Trasande, L.; Warhurst, A. M.; Muncke, J. Overview of known plastic packaging-associated chemicals and their hazards. Sci. Total. Environ.2019, 651, 3253–3268.

    CAS  PubMed  Google Scholar 

  3. 3

    Wang, Q.; Geng, Y.; Lu, X.; Zhang, S. First-row transition metal-containing ionic liquids as highly active catalysts for the glycolysis of poly(ethylene terephthalate) (PET). ACS Sustain. Chem. Eng.2015, 3, 340–348.

    CAS  Google Scholar 

  4. 4

    Meng, B.; Deng, J.; Liu, Q.; Wu, Z.; Yang, W. Transparent and ductile poly(lactic acid)/poly(butyl acrylate) (PBA) blends: structure and properties. Eur. Polym. J.2012, 48, 127–135.

    CAS  Google Scholar 

  5. 5

    Gu, L.; Nessim, E. E.; Li, T.; Macosko, C. W. Toughening poly(lactic acid) with poly(ethylene oxide)-poly(propylene oxide)poly(ethylene oxide) triblock copolymers. Polymer2018, 166, 261–269.

    Google Scholar 

  6. 6

    Chen, Y.; Wang, W.; Yuan, D.; Xu, C.; Cao, L.; Liang, X. Bio-based PLA/NR-PMMA/NR ternary thermoplastic vulcanizates with balanced stiffness and toughness: “soft-hard” core-shell continuous rubber phase, in situ compatibilization, and properties. ACS Sustain. Chem. Eng.2018, 6, 6488–6496.

    CAS  Google Scholar 

  7. 7

    Chen, B. K.; Wu, T. Y.; Chang, Y. M.; Chen, A. F. Ductile polylactic acid prepared with ionic liquids. Chem. Eng. J.2013, 886–893.

  8. 8

    Xu, H.; Xie, L.; Chen, J. B.; Jiang, X.; Hsiao, B. S.; Zhong, G. J.; Fu, Q.; Li, Z. M. Strong and tough micro/nanostructured poly(lactic acid) by mimicking the multifunctional hierarchy of shell. Mater. Horiz.2014, 1, 546–552.

    CAS  Google Scholar 

  9. 9

    Zhang, K.; Ran, X.; Wang, X.; Han, C.; Han, L.; Wen, X.; Zhuang, Y.; Dong, L. Improvement in toughness and crystallization of poly(L-lactic acid) by melt blending with poly(epichlorohydrin-co-ethylene oxide). Polym. Eng. Sci.2011, 51, 2370–2380.

    CAS  Google Scholar 

  10. 10

    Nagarajan, V.; Zhang, K.; Misra, M.; Mohanty, A. K. Overcoming the fundamental challenges in improving the impact strength and crystallinity of PLA biocomposites: influence of nucleating agent and mold temperature. ACS Appl. Mater. Interfaces2015, 7, 11203–14.

    CAS  PubMed  Google Scholar 

  11. 11

    Colomines, G.; Lee, A. V. D.; Robin, J. J.; Boutevin, B. Study of the crystallinity of polyesters derived from the glycolysis of PET. Macromol. Chem. Phys.2006, 207, 1461–1473.

    CAS  Google Scholar 

  12. 12

    Zhang, W.; Gui, Z.; Lu, C.; Cheng, S.; Cai, D.; Gao, Y. Improving transparency of incompatible polymer blends by reactive compatibilization. Mater. Lett.2013, 92, 68–70.

    CAS  Google Scholar 

  13. 13

    Evora, V.; Shukla, A. Fabrication, characterization, and dynamic behavior of polyester/TiO2 nanocomposites. Mater. Sci. Eng. A2003, 361, 358–366.

    Google Scholar 

  14. 14

    Chen, Y.; Pan, M.; Li, Y.; Xu, J. Z.; Zhong, G. J.; Ji, X.; Yan, Z.; Li, Z. M. Core-shell nanoparticles toughened polylactide with excellent transparency and stiffness-toughness balance. Compos. Sci. Technol.2018, 164, 168–177.

    CAS  Google Scholar 

  15. 15

    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-sttu formation of polylactide stereocomplex in the matrix. Paymer2017, 126, 231–239.

    CAS  Google Scholar 

  16. 16

    Choochottiros, C.; Chin, I. J. Potential transparent PLA impact modifiers based on PMMA copolymers. Eur. Polym. J.2013, 49, 957–966.

    CAS  Google Scholar 

  17. 17

    Leibler, L. Nanostructured plastics: joys of self-assembling. Prog. Polym. Sci.2005, 30, 898–914.

    CAS  Google Scholar 

  18. 18

    Parlak, O.; Demir, M. M. Toward transparent nanocomposites based on polystyrene matrix and PMMA-grafted CeO2 nanoparticles. ACS Appl. Mater. Interfaces2011, 3, 4306–14.

    CAS  PubMed  Google Scholar 

  19. 19

    Kim, P.; Li, C.; Riman, R. E.; Watkins, J. Refractive index tuning of hybrid materials for highly transmissive luminescent lanthanide particle-polymer composites. ACS Appl. Mater. Interfaces2018, 10, 9038–9047.

    CAS  PubMed  Google Scholar 

  20. 20

    Novak, B. Hybrid nanocomposite materials between inorganic glasses and organic polymers. Adv. Mater.1993, 5, 422–433.

    CAS  Google Scholar 

  21. 21

    Auras, R.; Harte, B.; Selke, S. An overview of polylactides as packaging materials. Macromol. Biosci.2004, 4, 835–64.

    CAS  PubMed  Google Scholar 

  22. 22

    Ljungberg, N.; Wesslén, B. Preparation and properties of plasticized poly(lactic acid) films. Biomacromolecules2005, 6, 1789–1796.

    CAS  PubMed  Google Scholar 

  23. 23

    Liu, B.; Jiang, L.; Liu, H.; Zhang, J. Synergetic effect of dual compatibilizers on in situ formed poly(lactic acid)/soy protein composites. Ind. Eng. Chem. Res.2010, 49, 6399–6406.

    CAS  Google Scholar 

  24. 24

    Lemmouchi, Y.; Murariu, M.; Santos, A. M. D.; Amass, A. J.; Schacht, E.; Dubois, P. Plasticization of poly(lactide) with blends of tributyl citrate and low molecular weight poly(D,L-lactide)-b-poly(ethylene glycol) copolymers. Eur. Polym. J.2009, 45, 2839–2848.

    CAS  Google Scholar 

  25. 25

    Ponkratov, D. O.; Lozinskaya, E. I.; Vlasov, P. S.; Aubert, P. H.; Plesse, C.; Vidal, F.; Vygodskii, Y. S.; Shaplov, A. S. Synthesis of novel families of conductive cationic poly(ionic liquid)s and their application in all-polymer flexible pseudo-supercapacitors. Electrochim. Acta2018, 281, 777–788.

    CAS  Google Scholar 

  26. 26

    Hayano, S.; Ota, K.; Ban, H. T. Syntheses, characterizations and functions of cationic polyethers with imidazolium-based ionic liquid moieties. Polym. Chem.2018, 9, 948–960.

    CAS  Google Scholar 

  27. 27

    Seki, S.; Tsuzuki, S.; Hayamizu, K.; Umebayashi, Y.; Serizawa, N.; Takei, K.; Miyashiro, H. Comprehensive refractive index property for room-temperature ionic liquids. J. Chem. Eng. Data.2012, 57, 2211–2216.

    CAS  Google Scholar 

  28. 28

    Shimizu, K.; Tariq, M.; Gomes, M. F. C.; Rebelo, L. P. N.; Lopes, J. N. C. Assessing the dispersive and electrostatic components of the cohesive energy of ionic liquids using molecular dynamics simulations and molar refraction data. J. Phys. Chem. B2010, 114, 5831–5834.

    CAS  PubMed  Google Scholar 

  29. 29

    Hu, H.; Yuan, W.; Jia, Z.; Baker, G. L. Ionic liquid-based random copolymers: a new type of polymer electrolyte with low glass transition temperature. RSC Adv.2015, 5, 3135–3140.

    CAS  Google Scholar 

  30. 30

    Hu, H.; Yuan, W.; Lu, L.; Zhao, H.; Jia, Z.; Baker, G. L. Low glass transition temperature polymer electrolyte prepared from ionic liquid grafted polyethylene oxide. J. Polym. Sci., Part A: Polym. Chem.2014, 52, 2104–2110.

    CAS  Google Scholar 

  31. 31

    Cui, J.; Nie, F. M.; Yang, J. X.; Pan, L.; Ma, Z.; Li, Y. S. Novel imidazolium-based poly(ionic liquid)s with different counterions for self-healing. J. Mater. Chem.2017, 5, 25220–25229.

    CAS  Google Scholar 

  32. 32

    Cui, J.; Ma, Z.; Pan, L.; An, C. H.; Liu, J.; Zhou, Y. F.; Li, Y. S. Self-healable gradient copolymers. Mater. Chem. Front.2019, 3, 464–471.

    CAS  Google Scholar 

  33. 33

    Huang, D.; Ding, Y.; Jiang, H.; Sun, S.; Ma, Z.; Zhang, K.; Pan, L.; Li, Y. Functionalized elastomeric ionomers used as effective toughening agents for poly(lactic acid): enhancement in interfacial adhesion and mechanical performance. ACS Sustain. Chem. Eng.2019, 8, 573–585.

    Google Scholar 

  34. 34

    Chen, L.; Hu, K.; Sun, S. T.; Jiang, H.; Huang, D.; Zhang, K. Y.; Pan, L.; Li, Y. S. Toughening poly(lactic acid) with imidazolium-based elastomeric ionomers. Chinese J. Polym. Sci.2018, 36, 1342–1352.

    CAS  Google Scholar 

  35. 35

    Hayano, S.; Ohta, K.; Ban, H. T. Highly deliquescent cationic polyether with imidazolium halide group. Chem. Lett.2017, 46, 1033–1035.

    CAS  Google Scholar 

  36. 36

    Prattipati, V.; Hu, Y. S.; Bandi, S.; Mehta, S.; Schiraldi, D. A.; Hiltner, A.; Baer, E. Improving the transparency of stretched poly(ethylene terephthalate)/polyamide blends. J. Appl. Polym. Sci.2006, 99, 225–235.

    CAS  Google Scholar 

  37. 37

    Wang, R.; Wang, S.; Zhang, Y. Morphology, mechanical properties, and thermal stability of poly(L-lactic acid)/poly(butylene succinate-co-adipate)/silicon dioxide composites. J. Appl. Polym. Sci.2009, 113, 3630–3637.

    CAS  Google Scholar 

  38. 38

    Singh, A. K.; Prakash, R.; Pandey, D. Evidence for in situ graft copolymer formation and compatibilization of PC and PMMA during reactive extrusion processing in the presence of the novel organometallic transesterification catalyst tin(II) 2-ethylhexanoate. RSC Adv.2012, 2, 10316–10323.

    CAS  Google Scholar 

  39. 39

    Nie, F. M.; Cui, J.; Zhou, Y. F.; Pan, L.; Ma, Z.; Li, Y. S. Molecular-level tuning toward aggregation dynamics of self-healing materials. Macromolecules2019, 52, 5289–5297.

    CAS  Google Scholar 

  40. 40

    Zhang, K.; Nagarajan, V.; Misra, M.; Mohanty, A. K. Supertoughened renewable PLA reactive multiphase blends system: phase morphology and performance. ACS Appl. Mater. Interfaces2014, 6, 12436–12448.

    CAS  PubMed  Google Scholar 

  41. 41

    Nagarajan, V.; Mohanty, A. K.; Misra, M. Perspective on polylactic acid (PLA) based sustainable materials for durable applications: focus on toughness and heat resistance. ACS Sustain. Chem. Eng.2016, 4, 2899–2916.

    CAS  Google Scholar 

  42. 42

    Hu, K.; Huang, D.; Jiang, H.; Sun, S.; Ma, Z.; Zhang, K.; Pan, L.; Li, Y. Toughening biosourced poly(lactic acid) and poly(3-hydroxybutyrate-co-4-hydroxybutyrate) blends by a renewable poly(epichlorohydrin-co-ethylene oxide) elastomer. ACS Omega2019, 4, 19777–19786.

    CAS  PubMed  PubMed Central  Google Scholar 

Download references

Acknowledgments

This work was financially supported by the National Natural Science Foundation of China (No. 51573130).

Author information

Affiliations

Authors

Corresponding authors

Correspondence to Kun-Yu Zhang or Li Pan.

Electronic Supplementary Information

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Sun, S., Wang, H., Huang, D. et al. Refractive Index Engineering as a Novel Strategy toward Highly Transparent and Tough Sustainable Polymer Blends. Chin J Polym Sci (2020). https://doi.org/10.1007/s10118-020-2439-1

Download citation

Keywords

  • Polylactide
  • Blending strategies
  • Refractive index matching
  • Poly(epichlorohydrin-co-ethylene oxide)
  • Ionomers