Abstract
The aim of this study was to reveal effects of accelerated weathering in neat polylactide (PLA) and its biocomposite reinforced with microcrystalline cellulose (MCC); compounded by twin-screw extrusion melt mixing and specimen shaping by injection molding. Weathering conditions were applied via consecutive steps of UV irradiation and humidity in accordance with ISO 4892–3 standards for 200 h. Various characterization techniques and mechanical tests indicated that photolysis, photo-oxidation and hydrolysis were the main degradation mechanisms leading to significant decrease in the molecular weight of PLA via main chain scission. Consequently, except elastic modulus other mechanical properties; strength, ductility and fracture toughness of PLA and PLA/MCC decreased substantially. However, after comparing the mechanical properties of the neat PLA and PLA/MCC biocomposite specimens having 200 h of accelerated weathering, it was concluded that; for the outdoor applications use of PLA/MCC biocomposite (with only 3 wt% MCC) was extremely beneficial compared to using neat PLA. For example, tensile strength is more than 91 % beneficial while strain at break ductility is more than 2.7 times beneficial.
References
Acioli-Moura, R., Sun, S. X., “Thermal Degradation and Physical Aging of Poly(lactic acid) and its Blends with Starch”, Polym. Eng. Sci., 48, 829–836 (2008) 10.1002/pen.21019Search in Google Scholar
Ahmed, J., VarshneyS.K., “Polylactides-Chemistry, Properties and Green Packaging Technology: A Review”, Inter. J. Food Properties, 14, 37–58 (2011) 10.1080/10942910903125284Search in Google Scholar
Chavez-MontesW.M., Gonzalez-Sanchez, G., Lopez-Martinez, E. I., Lira-Gomez, P. D., Ballinas-Casarrubias, L. and Flores-Gallardo, S., “Effect of Artificial Weathering on PLA/Nanocomposite Molecular Weight Distribution”, Polymer, 7, 760–776 (2015) 10.3390/polym7040760Search in Google Scholar
Copinet, A., Bertrand, C., Govindin, S., Coma, V. and Couturier, Y., “Effects of Ultraviolet Light (315 nm), Temperature and Relative Humidity on the Degradation of Polylactic Acid Plastic Films”, Chemosphere, 55, 763–773 (2004) 10.1016/j.chemosphere.2003.11.038Search in Google Scholar PubMed
Darie, R. N., Bodirlau, R., Teaca, C. A., Macyszyn, J., Kozlowski, M. and Spiridon, I., “Influence of Accelerated Weathering on the Properties of Polypropylene/Polylactic Acid/Eucalyptus Wood Biocomposites”, Int. J. Polym. Anal. Charact.18, 315–327 (2013) 10.1080/1023666X.2013.784936Search in Google Scholar
Deroine, M., Duigou, A. L., Corre, Y. M., Gac, Y. M. L., Davies, P., Cesar, G. and Bruzaud, S., “Accelerated Aging of Polylactide in Aqueous Environments: Comparative Study between Distilled Water and Seawater”, Polym. Degrad. Stab., 108, 319–329 (2014) 10.1016/j.polymdegradstab.2014.01.020Search in Google Scholar
Dogu, B., KaynakC., “Behavior of Polylactide/Microcrystalline Cellulose Biocomposites: Effects of Filler Content and Interfacial Compatibilization”, Cellulose, 23, 611–622 (2016) 10.1007/s10570-015-0839-0Search in Google Scholar
Fischer, E. W., Sterzel, H. J. and Wegner, G., “Investigation of Structure of Solution Grown Crystals of Lactide Copolymers by means of Chemical Reactions”, Coll. Polym. Sci., 251, 980–990 (1973) 10.1007/BF01498927Search in Google Scholar
Grigsby, W., Bridson, J., Lomas, C. and Elliot, J. A., “Esterification of Condensed Tannins and their Impact on the Properties of Poly(lactic acid)”, Polymer, 5, 344–360 (2013) 10.3390/polym5020344Search in Google Scholar
Hablot, E., Dharmalingam, S., Hayes, D. G., Wadsworth, L. C., Blazy, C. and Narayan, R., “Effect of Simulated Weathering on Physicochemical Properties and Inherent Biodegradation of PLA/PHA Nonowen Mulches”, J. Polym. Environ., 22, 417–429 (2014) 10.1007/s10924-014-0697-0Search in Google Scholar
Islam, M. S., Pickering, K. L. and Foreman, N. J., “Influence of Accelerated Ageing on the Physico-Mechanical Properties of Alkali-Treated Industrial Hemp Fibre Reinforced Poly(lactic acid) (PLA) Biocomposites”, Polym. Degrad. Stab., 95, 59–65 (2010) 10.1016/j.polymdegradstab.2009.10.010Search in Google Scholar
Janorkar, A. V., Metters, A. T. and Hirt, D. E., “Degradation of Poly(L-lactide) Films under Ultraviolet-Induced Photografting and Sterilization Conditions”, J. Appl. Polym. Sci., 106, 1042–1047 (2007) 10.1002/app.24692Search in Google Scholar
Kaygusuz, I., Kaynak, C., “Influences of Halloysite Nanotubes on Crystallization Behavior of Polylactide”, Plast. Rubber Compos. Macromol. Eng., 44, 41–49 (2015) 10.1179/1743289814Y.0000000116Search in Google Scholar
Kaynak, C., Kaygusuz, I., “Consequences of Accelerated Weathering in Polylactide Nanocomposites Reinforced with Halloysite Nanotubes”, J. Compos. Mat., 50, 365–375 (2016) 10.1177/0021998315575038Search in Google Scholar
Mathew, A. P., Oksman, K. and Sain, M., “Mechanical Properties of Biodegradable Composites from Poly Lactic Acid (PLA) and Microcrystalline Cellulose (MCC)”, J. Appl. Polym. Sci., 97, 2014–2025 (2005) 10.1002/app.21779Search in Google Scholar
Mohamad Haafiz, M. K., Hassan, A., Zakaria, Z., Inuwa, I. M., Islam, M. S. and Jawaid, M., “Properties of Polylactic Acid Composites Reinforced with Oil Palm Biomass Microcrystalline Cellulose”, Carbohydr. Polym.98, 139–145 (2013) 10.1016/j.carbpol.2013.05.069Search in Google Scholar PubMed
Moura, I., Botelho, G. and Machado, A. V., “Characterization of EVA/PLA Blends when Exposed to Different Environments”, J. Polym. Environ., 22, 148–157 (2014) 10.1007/s10924-013-0614-ySearch in Google Scholar
Mukherjee, T., Sani, M., Kao, N., Gupta, R. K., Quazi, N. and Bhattacharya, S., “Improved Dispersion of Cellulose Microcrystals in Polylactic Acid (PLA) based Composites Applying Surface Acetylation”, Chem. Eng. Sci., 101, 655–662 (2013) 10.1016/j.ces.2013.07.032Search in Google Scholar
Nampoothiri, K. M., Nair, N. R. and John, R. P. “An Overview of the Recent Developments in Polylactide (PLA) Research”, Bioresour. Technol., 101, 8493–8501 (2010) 10.1016/j.biortech.2010.05.092Search in Google Scholar PubMed
Ndazi, B. S., Karlsson, S., “Characterization of Hydrolytic Degradation of Polylactic Acid/Rice Hulls Biocomposites in Water at Different Temperatures”, eXPRESS Polym. Lett., 5, 119–131 (2011) 10.3144/expresspolymlett.2011.13Search in Google Scholar
Shinzawa, H., Nishida, M., Tanaka, T. and Kanematsu, W., “Accelerated Weathering-Induced Degradation of Poly(lactic acid) Fiber Studied by Near-Infrared (NIR) Hyperspectral Imaging”, Appl. Spectrosc., 66, 470–474 (2012) 10.1366/11-06540Search in Google Scholar PubMed
Spiridion, I., Paduraru, O. M., Zaltariov, M. F. and Darie, R. N., “Influence of Keratin on Polylactic Acid/Chitosan Composite Properties. Behavior upon Accelerated Weathering”, Ind. Eng. Chem. Res., 52, 9822–9833 (2013) 10.1021/ie400848tSearch in Google Scholar
Spiridion, I., Leluk, K., Resmerita, A. M. and Darie, R. N., “Evaluation of PLA-Lignin Bioplastics Properties before and after Accelerated Weathering”, Composites Part B, 69, 342–34 (2015) 10.1016/j.compositesb.2014.10.006Search in Google Scholar
Stloukal, P., Verney, V., Commereuc, S., Rychly, J., Matisova-Rychla, L., Pis, V. and Koutny, M., “Assessment of the Interrelation between Photooxidation and Biodegradation of Selected Polyesters after Artificial Weathering”, Chemosphere, 88, 1214–1219 (2012) 10.1016/j.chemosphere.2012.03.072Search in Google Scholar PubMed
Sztajnowski, S., Krucinska, I., Sulak, K., Puchalski, M., Wrzosek, H. and Bilska, J., “Effects of the Artificial Weathering of Biodegradable Spun-Bonded PLA Nonwovens in respect to their Application in Agriculture”, Fibres Text. East. Eur., 20, 89–95 (2012)Search in Google Scholar
Tsuji, H., Echizen, Y., Nishimura, Y.,“Photodegradation of Biodegradable Polyesters: A Comprehensive Study on Poly(L-lactide) and Poly(∊-caprolactone)”, Polym. Degrad. Stab., 91, 1128–1137 (2006) 10.1016/j.polymdegradstab.2005.07.007Search in Google Scholar
Xiao, L., Mai, Y., He, F., Yu, L., Zhang, L., Tang, H. and Yang, G., “Bio-Based Green Composites with High Performance from Poly(lactic acid) and Surface-Modified Microcrystalline Cellulose”, J. Mater. Chem., 22, 15732–15739 (2012) 10.1039/C2JM32373GSearch in Google Scholar
Yew, G. H., Chow, W. S., Mohd Ishak, Z. A. and Mohd Yusof, A. M., “Natural Weathering of Poly (lactic acid): Effects of Rice Starch and Epoxidized Natural Rubber”, J. Elastomers Plast., 41, 369–382 (2009) 10.1177/0095244309103663Search in Google Scholar
Zaidi, L., Kaci, M., Bruzaud, S., Bourmaud, A. and Grohens, Y., “Effect of Natural Weather on the Structure and Properties of Polylactide/Cloisite 30B Nanocomposites”, Polym. Degrad. Stab., 95, 1751–1758 (2010) 10.1016/j.polymdegradstab.2010.05.014Search in Google Scholar
Zhang, J., Tashiro, K., Domb, A. J. and Tsuji, H., “Confirmation of Disorder a Form of Poly(L-lactic acid) by X-Ray Fiber Pattern and Polarized IR/Raman Spectra Measured for Uniaxially-Oriented Samples”, Macromolecular Symposia, 242, 274–278 (2006) 10.1002/masy.200651038Search in Google Scholar
ZhangJ., Tashiro, K., Tsuji, H. and Domb, A. J., “Disorder-to-Disorder Phase Transition and Multiple Melting Behavior of Poly(L-lactide) Investigated by Simultaneous Measurements of WAXD and DSC”, Macromolecules, 41, 1352–1357 (2008) 10.1021/ma0706071Search in Google Scholar
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