Poly(lactic acid)/Polycaprolactone/Graphene Bionanocomposites: Microstructural, Mechanical and Thermal Properties

Document Type : Research Paper

Authors

1 Faculty of Mechanical Engineering, University of Hormozgan, P.O.Box 3995, Bandar-Abbas, Iran

2 Faculty of Chemical Engineering, University of Hormozgan, P.O.Box 3995,

Abstract

Hypothesis: Among the types of bioplastics, poly(lactic acid) (PLA) has the ability to compete with petroleum-based polymers due to its favorable properties such as high tensile strength and high modulus of elasticity. Brittleness is the main disadvantage of PLA which limits its practical applications in some industrial fields like packaging and textile. Blending of PLA with other flexible bioplastics like polycaprolactone (PCL) and adding nanoparticles like graphene into PLA are among the techniques that can be used to balance the stiffness and toughness of PLA.
Methods: Nanocomposites based on PLA/PCL/graphene (G) were prepared by melt mixing using an internal mixer with direct feeding method. In all samples the weight ratio of PCL dispersed phase to PLA matrix phase was 30:70, and three different weight percentages of nanographene (0.5, 1 and 2) were used. A rheometric mechanical spectrometer (RMS), X-ray diffractometer (XRD), and a scanning electron microscopy (SEM), as well as tensile and differential scanning calorimetry (DSC) measurements were used to study the microstructure, morphology, mechanical and thermal properties, respectively.
Findings: The results of XRD showed that graphene nanoparticles are well dispersed in the polymer matrix. The SEM results demonstrated that incorporation of graphene nanoparticles into the PLA/PCL sample led to a decrease in the PCL droplet size. The melt linear viscoelastic measurements showed that incorporation of 2% (by wt) of nanographene into PLA/PCL sample enhanced the storage modulus and complex viscosity by about 200 and 400% due to well-dispersion of nanoparticles in the matrix that led to the formation of a 3D network between nanographene and/or nanographene-polymer chains. The tensile test results showed that the elastic modulus tensile strength, and elongation-at-break increased by 126.63%, 80.48%, and 97.36% respectively, by adding 2% graphene nanoparticles to the PLA/PCL sample. The results of the thermal tests also showed that the addition of nanographene and PCL to the PLA polymer causes the nucleation effect and the creation of active nucleation centers, and the crystallinity percentage of the PLA phase increases, but the effect of PCL in this research was more evident than that of nanographene.

Keywords


  1. Chieng B.W., Ibrahim N.A., Yunus W.M.Z., Hussein M.Z., and Loo Y.Y., Effect of Graphene Nanoplatelets as Nanofiller in Plasticized Poly(lactic acid) Nanocomposites, Therm. Anal. Calorim., 118, 1551-1559, 2014.
  2. Huang G., Chen S., Song P., Lu P., Wu C., and Liang H., Combination Effects of Graphene and Layered Double Hydroxides on Intumescent Flame-Retardant Poly(methyl methacrylate) Nanocomposites, Clay. Sci., 88, 78-8, 2014.
  3. Muller J., González-Martínez C., and Chiralt A., Combination of Poly(lactic acid( and Starch for Biodegradable Food Packaging, Materials, 10, 952-956, 2017.
  4. Sinha Ray S.S. and Bousmina M., Biodegradable Polymers and Their Layered Silicate Nanocomposites, Greening the 21st Century Materials World, Mater. Sci., 50, 962-1079, 2005.
  5. Bordes P., Pollet E., and Avérous L., Nano-Biocomposites: Biodegradable Polyester/Nanoclay Systems, Polym. Sci., 34, 125-155, 2009.
  6. Avella M., Bogoeva G., Buzˇarovska A., Emanuela M.A., Gentile G., and Grozdanov A., Poly(lactic acid)-Based Biocomposites Reinforced with Kenaf Fibers, Appl. Poly. Sci., 108, 3542-3551, 2008.
  7. Ren J., Wang Q.F., Gu S.Y., Zhang N.W., and Ren T.B., Chain-Linked Lactic Acid Polymers by Benzene Diisocyanate, J. Appl. Polym. Sci., 99, 1045-1049, 2006.
  8. Gupta A.P. and Kumar V., New Emerging Trends in Synthetic Biodegradable Polymers-Polylactide: A Critique, Polym. J., 43, 4053-4074, 2007.
  9. Lim L.T., Auras R., and Rubino M., Processing Technologies for Poly(lactic acid). Polym. Sci., 33, 820-852, 2008.
  10. Araújo A., Botelhoa G., Oliveira M., and Machado A.V., Influence of Clay Organic Modifier on the Thermal-Stability of PLA Based Nanocomposites, Clay Sci., 88, 144-150, 2014.
  11. Huda M.S., Drzal L.T., Mohanty A.K., and Misra M., The Effect of Silane Treated- and Untreated-Talc on the Mechanical and Physic Mechanical Properties of Poly(lactic acid)/Newspaper Fibers/Talc Hybrid Composites, Compos. Eng., 38, 367-379, 2007.
  12. Shirai M.A., Grossmann M.V.E., Mali S., Yamashita F., Garcia P.S., and Müller C.M.O., Development of Biodegradable Flexible Films of Starch and Poly(lactic acid) Plasticized with Adipate or Citrate Esters, Polym., 92, 19-22, 2013.
  13. Tee Y.B., Talib R.A., Abdan K., Chin N.L., Basha R.K., and Yunos K.F.M., Toughening Poly(lactic acid) and Aiding the Melt-Compounding with Bio-Sourced Plasticizers, Agric. Sci. Procedia, 2, 289-295, 2014.
  14. Yeh J.T., Wu C.J., Tsuo C.H., Chai W.L., Chow J.D., Huang CY., Chen K.N., and Wu C.S., Study on the Crystallization, Miscibility, Morphology, Properties of Poly(lactic acid)/Poly(e-caprolactone) Blends, Plast. Technol. Eng., 48, 571-578, 2009.
  15. Wang L.F., Rhim J.W., and Hong S.I., Preparation of Polylactide/Poly(butylene adipate-co-terephthalate) Blend Films Using a Solvent Casting Method and Their Food Packaging Application, LWT-Food Sci. Technol., 68, 454-461, 2016.
  16. Suman K.N.S., Rao V.K., and Bhanukiran K., Study of Rheological and Mechanical Properties of Biodegradable Polylactide and Polycaprolactone Blends, J. Eng. Sci. Technol., 3, 6259-6264. 2011.
  17. Shen T., Lu M., and Liang L., Modification of the Properties of Polylactide/Polycaprolactone Lends by Incorporation of Blocked Polyisocyanate, Macromol. Sci. A, 50, 547-554, 2013.
  18. Monticelli O., Calabrese M., Gardella L., Fina A., and Gioffredi E., Silsesquioxanes: Novel Compatibilizing Agents for Tuning the Microstructure and Properties of PLA/PCL Immiscible Blends, Polym. J., 58, 69-78, 2014.
  19. Sabet S.S. and Katbab A.A., Interfacially Compatibilized Poly(lactic acid) and Poly(lactic acid)/Polycaprolactone/Organoclay Nanocomposites with Improved Biodegradability and Barrier Properties: Effects of the Compatibilizer Structural Parameters and Feeding Route, Appl. Polym. Sci., 111, 1954-1963, 2009.
  20. Bouakaz B.S., Pillin I., Habi A., and Grohens Y., Synergy Between Fillers in Organomontmorillonite/Graphene-PLA Nanocomposites, Clay. Sci., 116, 69-77, 2015.
  21. Neppalli R., Causin V., Marega C., Modesti M., Adhikari R., Scholtyssek S., Ray S.S., and Marigo A., The Effect of Different Clays on the Structure, Morphology and Degradation Behavior of Poly(lactic acid), Clay Sci., 87, 278-284, 2014.
  22. Luduena L.N., Alvarez V.A., and Vazquez A., Processing and Microstructure of PCL/Clay Nanocomposites, Sci. Eng. A, 460, 121-129, 2007.
  23. Botlhoko O.J., Ray S.S., and Ramontja J., Influence of Functionalized Exfoliated Reduced Graphene Oxide Nanoparticle Localization on Mechanical, Thermal and Electronic Properties of Nanobiocomposites, Polym. J., 102, 130-140, 2018.
  24. Parandeh S., Kharaziha M., and Karimzadeh F., An Eco-Friendly Triboelectric Hybrid Nanogenerators Based on Graphene Oxide Incorporated Polycaprolactone Fibers and Cellulose Paper, Energy, 59, 412-421. 2019.
  25. Manafi P., Ghasemi I., Karrabi M., Azizi H., Manafi M.R., and Ehsaninamin P., Thermal Stability and Thermal Degradation Kinetics (Model-Free Kinetics) of Nanocomposites Based on Poly(lactic acid)/Graphene: The Influence of Functionalization, Bull., 72, 1095-1112, 2015.
  26. Kelnar I., Kratochvil J., Kapralkova L., Zhigunov A., and Nevoralova M., Graphite Nanoplatelets-Modified PLA/PCL: Effect of Blend Ratio and Nanofiller Localization on Structure and Properties, J. Mech. Behav. Biomed. Mater., 71, 271-278, 2017.
  27. Wang X., Gao Y., Li X., Xu Y., Jiang J., Hou J., Li Q., and Turng L.S., Selective Localization of Graphene Oxide in Electrospun Polylactic Acid/Poly(e-caprolactone) Blended Nanofibers, Test., 59, 396-403, 2017.
  28. Masarra N.A., Batistella M., Quantin J.C., Regazzi A., Pucci M.F., El Hage R., and Lopez-Cuesta J.M., Fabrication of PLA/PCL/Graphene Nanoplatelet (GNP) Electrically Conductive Circuit Using the Fused Filament Fabrication (FFF) 3D Printing Technique, Materials, 15, 762, 2022.
  29. Pinto A.M., Cabral J., Tanaka D.A.P., Mendes A.M., and Magalhaes F.D., Effect of Incorporation of Graphene Oxide and Graphene Nanoplatelets on Mechanical and Gas Permeability Properties of Poly(lactic acid) Films, Int., 62, 33-40, 2013.
  30. Song J., Gao H., Zhu G., Cao X., Shi X., and Wang Y., The Preparation and Characterization of Polycaprolactone/Graphene Oxide Biocomposite Nanofiber Scaffolds and Their Application for Directing Cell Behaviors, Carbon, 95, 1039-1050,
  31. Cao Y., Feng J., and Wu P., Preparation of Organically Dispersible Graphene Nanosheets Powders Through a Lyophilizationmethod and Their Poly(lactic acid) Composites, Carbon, 48, 3834-3839, 2010.
  32. Malinowski R., Mechanical Properties of PLA/PCL Blends Crosslinked by Electron Beam and Taic Additive, Chem. Phys. Lett., 662, 91-96, 2016.
  33. Semba T., Kitagawa K., Ishiaku U.S., and Hamada H., The Effect of Crosslinking on the Mechanical Properties of Polylactic Acid/Polycaprolactone Blends, J, Appl. Polym. Sci, 101, 1816-1825, 2006.
  34. Ferri J.M., Fenollar O., Jorda-Vilaplana A., García-Sanoguera D., and Balart R., Effect of Miscibility on Mechanical and Thermal Properties of Poly(lactic acid)/Polycaprolactone Blends, Int., 65, 453-463, 2016.
  35. Aydogdu M.O., Altun E., Ahmed J., Gunduz O., and Edirisinghe M., Fiber Forming Capability of Binary and Ternary Compositions in the Polymer System: Bacterial Cellulose–Polycaprolactone–Polylactic Acid, Polymers, 11, 1148, 2019.
  36. Lu H. and Kazarian S.G., How Does High-Pressure CO2 Affect the Morphology of PCL/PLA Blends? Visualization of Phase Separation Using in Situ ATR-FTIR Spectroscopic Imaging, Acta, A: Mol. Biomol. Spectrosc., 243, 118760, 2020.
  37. Mofokeng J.P. and Luyt A.S., Morphology and Thermal Degradation Studies of Melt-Mixed Poly(lactic acid)(PLA)/Poly(e-caprolactone)(PCL) Biodegradable Polymer Blend Nanocomposites with TiO2 as Filler, Test., 45, 93-100, 2015.
  38. Liu Y., Liu G., Li M., and He C., Synthesis, Characterization, and Hydrolytic Degradation of Polylactide/Poly(caprolactone)/Nano-Silica Composites, Macromol. Sci. A, 54, 813-818, 2017.
  39. Urquijo J., Dagréou S., Guerrica-Echevarría G., and Eguiazábal J.I., Morphology and Properties of Electrically and Rheologically Percolated PLA/PCL/CNT Nanocomposites, Appl. Polym. Sci, 134, 45265, 2017.
  40. Zhao H. and Zhao G., Mechanical and Thermal Properties of Conventional and Microcellular Injection Molded Poly(lactic acid)/Poly(e-caprolactone) Blends, Mech. Behav. Biomed. Mater., 53, 59-67, 2016.
  41. Yeh J.T., Wu C.J., Tsou C.H., Chai W.L., Chow J.D., Huang C.Y., Chen K.N., and Wu C.S., Study on the Crystallization, Miscibility, Morphology, Properties of Poly(lactic acid)/Poly(e-caprolactone) Blends, Plast. Technol. Eng., 48, 571-578, 2009.
  42. Noroozi N., Schafer L.L., and Hatzikiriakos S.G., Thermorheological Properties of Poly(e-caprolactone)/Polylactide Blends, Eng. Sci., 52, 2348-2359, 2012.
  43. Peponi L., Sessini V., Arrieta M.P., Navarro-Baena I., Sonseca A., Dominici F., Gimenez E., Torre L., Tercjak A., López D., and Kenny J.M., Thermally-Activated Shape Memory Effect on Biodegradable Nanocomposites Based on PLA/PCL Blend Reinforced with Hydroxyapatite, Degrad. Stab., 151, 36-51, 2018.
  44. Sadeghi A., Razavi S.M.A., and Shahrampour D., Fabrication and Characterization of Biodegradable Active Films with Modified Morphology Based on Polycaprolactone-Polylactic Acid-Green Tea Extract, J. Biol. Macromol., 205, 341-356, 2022.
  45. Wang B., Ye X., Wang B., Li X., Xiao S., and Liu H., Reactive Graphene as Highly Efficient Compatibilizer for Cocontinuous Poly(lactic acid)/Poly(e-caprolactone) Blends Toward Robust Biodegradable Nanocomposites, Sci. Technol., 221, 109326, 2022.
  46. Shen Y., Yang J., Zhang N., Huang T., Wang Y., Li M., Lis., and Zhang C., Well Dispersion of Rgos in PLLA Matrix Mediated by Incorporation of EVA and Its Resultant Electrical Property, Compos., 35, 1051-1059, 2014.
  47. Wang Y. and Lin C.S., Preparation and Characterization of Maleated Polylactide Functionalized Graphite Oxide Nanocomposites, Polym. Res., 21, 334-347, 2014.
  48. Wang H., Qian Q., Jiang X., Liu X., Xiao L., Huang B., and Chen Q., Melt Rheological and Compatibility Properties of Recycled Poly(ethylene terephthalate)/Poly(acrylonitrile-butadiene-styrene) Blends, Appl. Polym. Sci., 126, E266-E272, 2012.
  49. Li K., Peng J., Turng L.S. and Huang H.X., Dynamic Rheological Behavior and Morphology of Polylactide/Poly(butylenes adipate-co-terephthalate) Blends with Various Composition Ratios, Polym. Technol., 30, 150-157, 2011.
  50. Prevey S., X-Ray Diffraction Residual Stress Techniques, ASM International, ASM Handbook, 10, 380-392, 1986.
  51. Sarazin P., Li G., Orts W.J., and Favis B.D., Binary and Ternary Blends of Polylactide, Polycaprolactone and Thermoplastic Starch, Polymer, 49, 599-609, 2008.
  52. Zakeri N., Rezaie H.R., Javadpour J., and Kharaziha M., Fabrication and Characterization of Polycaprolactone-Zeolite Ynanocomposite for Bone Tissue Engineering, Mater. Eng., 39, 77-94, 2020.
  53. Sumita M., Sakata K., and Asai S., Dispersion of Fillers and the Electrical Conductivity of Polymer Blends Filled with Carbon Black,  Bull, 25, 265-271, 1991.
  54. Wu D., Lin D., Zhang J., Zhou W., Zhang M., Zhang Y., Wang D., and Lin B., Selective Localization of Nanofillers: Effect on Morphology and Crystallization of PLA/PCL Blends, Chem. Phys., 212, 613-626, 2011.
  55. Forouharshad M., Gardella L., Furfaro D., Galimberti M., and Monticelli O., A Low Environmental-Impact Approach for Novel Biocomposites Based on PLLA/PCL Blends and High Surface Area Graphite, Polym. J., 70, 28-36, 2015.
  56. De Aguiar J., Decol M., Mauricio Pachekoski W.M., and Becker D., Mixing-Sequence Controlled Selective Localization of Carbon Nanoparticles in PLA/PCL Blends, Eng. Sci., 59, 323-329, 2018.
  57. Sessini V., Navarro-Baena I., Arrieta M.P., Dominici F., Lopez D., Torre L., Kenny J.M., Dubois P., Raquez J.M., and Peponi L., Effect of the Addition of Polyester-Grafted-Cellulose Nanocrystals on the Shape Memory Properties of Biodegradable PLA/PCL Nanocomposites, Degrad. Stab., 152, 126-138, 2018.
  58. Ahmadzadeh Y., Babaei A., and Goudarzi A., Assessment of Localization and Degradation of ZnO Nano-Particles in the PLA/PCL Biocompatible Blend Through a Comprehensive Rheological Characterization, Degrad. Stab., 158, 136-147, 2018.
  59. Abdolrasouli M.H., Nazockdast H., Sadeghi G.M., and Kaschta J., Morphology Development, Melt Linear Viscoelastic Properties and Crystallinity of Polylactide/Polyethylene/Organoclay Blend Nanocomposites, Appl. Polym Sci., 132, 41300-41310, 2015.
  60. Wachirahuttapong S., Thongpin C., and Sombatsompop N., Effect of PCL and Compatibility Contents on the Morphology, Crystallization and Mechanical Properties of PLA/PCL Blends, Energy Procedia, 89,198-206, 2016.
  61. Yasuniwa M., Tsubakihara S., and Murakami T., High-Pressure DTA of Poly(butylene terephthalate), Poly(hexamethylene terephthalate), and Poly(ethylene terephthalate), Polym. Sci. B: Polym. Phys., 38, 262-272, 2000.
  62. Quiles-Carrillo L., Montanes N., Pineiro F., Jorda-Vilaplana A., and Torres-Giner S., Ductility and Toughness Improvement of Injection- Molded Compostable Pieces of Polylactide by Melt Blending with Poly(e-caprolactone) and Thermoplastic Starch, Materials, 11, 2138, 2018.