Development of Biodegradable Polymer-Based Composite Materials for Sustainable Packaging Applications: A Micromechanical and Barrier Modelling Assessment of Cellulose-Reinforced Polylactide Films
Keywords:
biodegradable polymers; polylactide; cellulose nanocrystals; Halpin–Tsai model; barrier properties; sustainable packaging; compostabilityAbstract
Biodegradable polymer composites are widely proposed as replacements for petrochemical packaging films, but the trade-off at the centre of the proposition is rarely quantified: reinforcement that improves stiffness and barrier performance simultaneously slows the end-of-life degradation that justifies the material in the first place. This article quantifies that trade-off within a single declared modelling framework for polylactide reinforced with cellulose nanocrystals. Tensile modulus was predicted by the Halpin–Tsai equations for aligned and randomly oriented reinforcement, tensile strength by the Kelly–Tyson sub-critical treatment with a stated interfacial shear strength of 25 MPa, and permeability by the Nielsen tortuosity model. At 5 wt% loading, corresponding to a volume fraction of 3.92 %, the framework predicts a randomly oriented modulus of 4.63 GPa against 3.40 GPa for the unfilled matrix, a gain of 36.2 %, and a tensile strength of 72.4 MPa, a gain of 31.6 %. Over the same interval the relative permeability falls to 0.690, reducing the predicted water-vapour transmission rate of a 25 µm film from 165 to 114 g m⁻² d⁻¹ and the oxygen transmission rate from 310 to 214 cm³ m⁻² d⁻¹. Barrier improvement is shown to be governed far more strongly by reinforcement aspect ratio than by loading. A logistic mineralisation model indicates that the same 5 wt% formulation reaches 80.6 % cumulative mineralisation at 180 days against 86.9 % for the unfilled matrix, or 86.7 % of the cellulose reference, and therefore sits below the relative threshold applied under industrial compostability standards.
References
[1] Auras, R., Harte, B., & Selke, S. (2004). An overview of polylactides as packaging materials. Macromolecular Bioscience, 4(9), 835–864.
[2] Bharadwaj, R. K. (2001). Modeling the barrier properties of polymer-layered silicate nanocomposites. Macromolecules, 34(26), 9189–9192.
[3] Dufresne, A. (2013). Nanocellulose: A new ageless bionanomaterial. Materials Today, 16(6), 220–227.
[4] Favier, V., Chanzy, H., & Cavaillé, J. Y. (1995). Polymer nanocomposites reinforced by cellulose whiskers. Macromolecules, 28(18), 6365–6367.
[5] Fischer, E. W., Sterzel, H. J., & Wegner, G. (1973). Investigation of the structure of solution grown crystals of lactide copolymers by means of chemical reactions. Kolloid-Zeitschrift und Zeitschrift für Polymere, 251(11), 980–990.
[6] Fortunati, E., Armentano, I., Zhou, Q., Iannoni, A., Saino, E., Visai, L., Berglund, L. A., & Kenny, J. M. (2012). Multifunctional bionanocomposite films of poly(lactic acid), cellulose nanocrystals and silver nanoparticles. Carbohydrate Polymers, 87(2), 1596–1605.
[7] Garlotta, D. (2001). A literature review of poly(lactic acid). Journal of Polymers and the Environment, 9(2), 63–84.
[8] Geyer, R., Jambeck, J. R., & Law, K. L. (2017). Production, use, and fate of all plastics ever made. Science Advances, 3(7), e1700782.
[9] Habibi, Y., Lucia, L. A., & Rojas, O. J. (2010). Cellulose nanocrystals: Chemistry, self-assembly, and applications. Chemical Reviews, 110(6), 3479–3500.
[10] Halpin, J. C., & Kardos, J. L. (1976). The Halpin–Tsai equations: A review. Polymer Engineering & Science, 16(5), 344–352.
[11] Iwata, T. (2015). Biodegradable and bio-based polymers: Future prospects of eco-friendly plastics. Angewandte Chemie International Edition, 54(11), 3210–3215.
[12] Kale, G., Auras, R., & Singh, S. P. (2007). Comparison of the degradability of poly(lactide) packages in composting and ambient exposure environments. Packaging Technology and Science, 20(1), 49–70.
[13] Kelly, A., & Tyson, W. R. (1965). Tensile properties of fibre-reinforced metals: Copper/tungsten and copper/molybdenum. Journal of the Mechanics and Physics of Solids, 13(6), 329–350.
[14] Lim, L.-T., Auras, R., & Rubino, M. (2008). Processing technologies for poly(lactic acid). Progress in Polymer Science, 33(8), 820–852.
[15] Moon, R. J., Martini, A., Nairn, J., Simonsen, J., & Youngblood, J. (2011). Cellulose nanomaterials review: Structure, properties and nanocomposites. Chemical Society Reviews, 40(7), 3941–3994.
[16] Nielsen, L. E. (1967). Models for the permeability of filled polymer systems. Journal of Macromolecular Science: Part A — Chemistry, 1(5), 929–942.
[17] Oksman, K., Aitomäki, Y., Mathew, A. P., Siqueira, G., Zhou, Q., Butylina, S., Tanpichai, S., Zhou, X., & Hooshmand, S. (2016). Review of the recent developments in cellulose nanocomposite processing. Composites Part A: Applied Science and Manufacturing, 83, 2–18.
[18] Peelman, N., Ragaert, P., De Meulenaer, B., Adons, D., Peeters, R., Cardon, L., Van Impe, F., & Devlieghere, F. (2013). Application of bioplastics for food packaging. Trends in Food Science & Technology, 32(2), 128–141.
[19] Rhim, J.-W., Park, H.-M., & Ha, C.-S. (2013). Bio-nanocomposites for food packaging applications. Progress in Polymer Science, 38(10–11), 1629–1652.
[20] Sanchez-Garcia, M. D., & Lagaron, J. M. (2010). On the use of plant cellulose nanowhiskers to enhance the barrier properties of polylactic acid. Cellulose, 17(5), 987–1004.
[21] Siqueira, G., Bras, J., & Dufresne, A. (2010). Cellulosic bionanocomposites: A review of preparation, properties and applications. Polymers, 2(4), 728–765.
[22] Vert, M., Doi, Y., Hellwich, K.-H., Hess, M., Hodge, P., Kubisa, P., Rinaudo, M., & Schué, F. (2012). Terminology for biorelated polymers and applications. Pure and Applied Chemistry, 84(2), 377–410.
[23] Wang, J., Gardner, D. J., Stark, N. M., Bousfield, D. W., Tajvidi, M., & Cai, Z. (2018). Moisture and oxygen barrier properties of cellulose nanomaterial-based films. ACS Sustainable Chemistry & Engineering, 6(1), 49–70.
[24] Šturcová, A., Davies, G. R., & Eichhorn, S. J. (2005). Elastic modulus and stress-transfer properties of tunicate cellulose whiskers. Biomacromolecules, 6(2), 1055–1061.