Thermoplastic cassava starch/sorbitol-modified montmorillonite nanocomposites blended with low density polyethylene: properties and biodegradability study
Keywords:
cassava starch, Montmorillonite, Nanocomposite, LDPE, Impact and flexural strength, BiodegradabilityAbstract
The objective of this research paper is to prepare environmentally friendly plastic materials from biodegradable cassava starch, montmorillonite (MMT) and low density polyethylene (LDPE). MMT was first modified by sorbitol via a solid state method. Results from X-ray diffraction (XRD) indicated that sorbitol molecules were intercalated in between MMT layers along 001 direction. Cassava starch was plasticized with sorbitol and formamide on a two-roll mill to obtain thermoplastic starch (TPS). The TPS/modified-MMT nanocomposites were prepared by means of melt blending of TPS with various amounts of MMT (0, 2, 4, and 6 phr). XRD and transmission electron microscopy (TEM) results showed that the nanocomposites formed were all exfoliated. The prepared nanocomposites were subsequently blended with a mixture of 80 LDPE/20 PE wax on a two-roll mill followed by a compression molding machine. The obtained polymer blends were examined for their impact and flexural strength, water absorption, morphology and biodegradability. The mechanical properties of LDPE were improved by incorporating 10 phr of TPS nanocomposite that contained MMT 2 phr and gained the highest impact and flexural strengths of 2900 J m-2 and 17 N m-2, respectively. The scanning electron micrographs displayed that the TPS nanocomposites with a high loading of starch and MMT exhibited poor distribution in PE matrix. Water absorption and biodegradability of the nanocomposites were enhanced with the increasing amount of cassava starch. However, silicate layers with high aspect ratio could serve as a barrier and reduce the water-uptake ability of these materials.Downloads
References
Avella, M., De Vlieger, J.J., Errico, M.E., Fischer, S., Vacca, P. and Volpe, M.G. 2005. Biodegradable starch/clay nanocomposite films for food packaging applications. Food Chem. 93(3) : 467-474.
Thakore, I.M., Desai, S., Sarawade, B.D. and Devi, S. 2001. Studies on biodegradability, morphology and thermomechanical properties of LDPE/modified starch blends. Eur. Polym. J. 37(1) : 151-160.
Chiu, F.C., Lai, S.M. and Ti, K.T. 2009. Characterization and comparison of metallocene-catalyzed polyethylene/thermoplastic starch blends and nanocomposites. Polym. Test. 28(3) : 243-250.
Huang, C.Y., Roan, M.L., Kuo, M.C. and Lu, W.L. 2005. Effect of compatibiliser on the biodegradation and mechanical properties of high-content starch/low-density polyethylene blends. Polym. Degradation. Stab. 90(1) : 95-105.
Tang, S., Zou, P., Xiong, H. and Tang, H. 2008. Effect of nano-SiO2 on the performance of starch/polyvinyl alcohol blend films. Carbohyd. Polym. 72(3) : 521-526.
Ma, X., Yu, J. and Wang, N. 2007. Production of thermoplastic starch/MMT-sorbitol nanocomposites by dual-melt extrusion processing. Macromol. Mater.Eng. 292(6) : 723-728.
Park, H.R., Chough, S.H., Yun, Y.H. and Yoon, S.D. 2005. Properties of starch/PVA blend films containing citric acid as additive. J. Polym. Environ. 13(4) : 375-382.
Carvalho, A.J.F., Job, A.E., Curvelo, A.A.S. and Gandini, A. 2003. Thermoplastic starch/ natural rubber blends. Carbohyd. Polym. 53(1) :1-5.
Mano, J.F., Koniarova, D. and Reis, R.L. 2003. Thermal properties of thermoplastic starch/ synthetic polymer blends with potential biomedical applicability. J. Mater. Sci.: Mater. Med. 14(2) : 127-135.
Choudalakis, G. and Gotsis, A.D. 2009. Permeability of polymer/clay nanocomposites: A review. Eur. Polym. J. 45(4) : 967-984.
Yang, J.H., Yu, J.G. and Ma, X.F. 2006. Preparation and properties of ethylenebisformamide plasticized potato starch (EPTPS). Carbohyd Polym. 63(2) : 218-223.
Mingliang, G. 2009. Preparation and properties of polypropylene/clay nanocomposites using an organoclay modified through solid state method. J. Reinf. Plast. Compos. 28(1) : 5-15.
Fedullo, N., Sorlier, E., Sclavons, M., Bailly, C., Lefebvre, J.M. and Devaux, J. 2006. Polymerbased nanocomposites: Overview, applications and perspectives. Prog. Org. Coatings. 58(2-3) : 87-95.
Giannakas, A., Spanos, C.G., Koirkoumelis, N., Vaimakis, T. and Ladavos, A. 2008. Preparation, characterization and water barrier properties of PS/organo-montmorillonite nanocomposites. Eur. Polym. J. 44(12) : 3915-3921.
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2017 Journal of Metals, Materials and Minerals
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Authors who publish in this journal agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgment of the work's authorship and initial publication in this journal.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal.
