Influence of plasticizers on the compostability of polylactic acid

[EN] Poly(lactic acid) (PLA) has gained considerable attention as an interesting biobased and biodegradable polymer for film for food packaging applications, due to its many advantages such as biobased nature, high transparency and inherent biodegradable/compostable character. With the dual objective to improve PLA processing performance and to obtain flexible materials, plasticizer are use as strategy for extending PLA applications as compostable film for food packaging applications. Several plasticizers (i.e.: citrate esters, polyethylene glycol (PEG), oligomeric lactic acid (OLA), etc.) as well as essential oils and maleinized and/or epoxidized seed oils are widely used for flexible PLA film production. This article reviews the most relevant compostable PLA-plasticized flexible film formulations with an emphasis on plasticizer effect on the compostability rate of PLA polymeric matrix with the aim to get information of the possibility to use plasticized PLAbased formulatios as compostable films for sustainable industrial packaging production.M.P. Arrieta wants to thank Prof. Juan López-Martínez from Instituto de Tecnología de Materiales, Universitat Politècnica de València (EPSA-UPV, Spain) and Prof. José María Kenny from Civil and Environmental Engineering Department, Materials Engineering Centre, University of Perugia (UdR INSTM,, Italy), for their continuous support.Arrieta, MP. (2021). Influence of plasticizers on the compostability of polylactic acid. Journal of Applied Research in Technology & Engineering. 2(1):1-9. https://doi.org/10.4995/jarte.2021.14772OJS1921Abdelwahab, M.A., Flynn, A., Chiou, B.S., Imam, S., Orts, W., Chiellini, E. (2012). 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Polyurethane based on PLA and PCL incorporated with catechin: Structural, thermal and mechanical characterization. European Polymer Journal, 89, 174-184. https://doi.org/10.1016/j.eurpolymj.2017.02.028Arrieta, M.P., Peponi, L., López, D., Fernández-García, M. (2018). Recovery of yerba mate (Ilex paraguariensis) residue for the development of PLA-based bionanocomposite films. Industrial Crops and Products, 111, 317-328. https://doi.org/10.1016/j.indcrop.2017.10.042Arrieta, M.P., Perdiguero, M., Fiori, S., Kenny, J.M., Peponi, L. (2020). Biodegradable electrospun PLA-PHB fibers plasticized with oligomeric lactic acid. Polymer Degradation and Stability, 179. https://doi.org/10.1016/j.polymdegradstab.2020.109226Arrieta, M.P., Samper, M.D., Aldas, M., López, J. (2017). On the use of PLA-PHB blends for sustainable food packaging applications. Materials, 10(9), 1008. https://doi.org/10.3390/ma10091008Arrieta, M.P., Sessini, V., Peponi, L. (2017). Biodegradable poly(ester-urethane) incorporated with catechin with shape memory and antioxidant activity for food packaging. European Polymer Journal, 94, 111-124.https://doi.org/10.1016/j.eurpolymj.2017.06.047Auras, R.A., Harte, B., Selke, S., Hernandez, R. (2003). Mechanical, physical, and barrier properties of poly(lactide) films. Journal of Plastic Film and Sheeting, 19(2), 123-135. https://doi.org/10.1177/8756087903039702Auras, R., Harte, B., Selke, S.E. (2004). An overview of polylactides as packaging materials. Macromolecular Bioscience, 4(9), 835-864. https://doi.org/10.1002/mabi.200400043Balart, J., Montanes, N., Fombuena, V., Boronat, T., Sánchez-Nacher, L. (2018). Disintegration in compost conditions and water uptake of green composites from poly (lactic acid) and hazelnut shell flour. Journal of Polymers and the Environment, 26(2), 701-715. https://doi.org/10.1007/s10924-017-0988-3Beltrán, F.R., Arrieta, M.P., Gaspar, G., de la Orden, M.U., Urreaga, J.M. (2020). 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A Deeper Microscopic Study of the Interaction between Gum Rosin Derivatives and a Mater-Bi Type Bioplastic

[EN] The interaction between gum rosin and gum rosin derivatives with Mater-Bi type bioplastic, a biodegradable and compostable commercial bioplastic, were studied. Gum rosin and two pentaerythritol esters of gum rosin (Lurefor 125 resin and Unik Tack P100 resin) were assessed as sustainable compatibilizers for the components of Mater-Bi® NF 866 polymeric matrix. To study the influence of each additive in the polymeric matrix, each gum rosin-based additive was compounded in 15 wt % by melt-extrusion and further injection molding process. Then, the mechanical properties were assessed, and the tensile properties and impact resistance were determined. Microscopic analyses were carried out by field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and atomic force microscopy with nanomechanical assessment (AFM-QNM). The oxygen barrier and wettability properties were also assayed. The study revealed that the commercial thermoplastic starch is mainly composed of three phases: A polybutylene adipate-co-terephthalate (PBAT) phase, an amorphous phase of thermoplastic starch (TPSa), and a semi-crystalline phase of thermoplastic starch (TPSc). The poor miscibility among the components of the Mater-Bi type bioplastic was confirmed. Finally, the formulations with the gum rosin and its derivatives showed an improvement of the miscibility and the solubility of the components depending on the additive usedThis research was funded by Spanish Ministry of Economy and Competitiveness (MINECO), project: PROMADEPCOL (MAT2017-84909-C2-2-R) and M.P.A. s contract: Juan de la Cierva-Incorporación (FJCI-2017-33536).Aldas-Carrasco, MF.; Rayón, E.; López-Martínez, J.; Arrieta, MP. (2020). A Deeper Microscopic Study of the Interaction between Gum Rosin Derivatives and a Mater-Bi Type Bioplastic. Polymers. 12(1):1-17. https://doi.org/10.3390/polym12010226S117121Keshavarz, T., & Roy, I. 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Biocomposites of Alfa fibers dispersed in the Mater-Bi® type bioplastic: Morphology, mechanical and thermal properties. Composites Part A: Applied Science and Manufacturing, 78, 371-379. doi:10.1016/j.compositesa.2015.08.023Sessini, V., Arrieta, M. P., Fernández-Torres, A., & Peponi, L. (2018). Humidity-activated shape memory effect on plasticized starch-based biomaterials. Carbohydrate Polymers, 179, 93-99. doi:10.1016/j.carbpol.2017.09.070Arrieta, M., Samper, M., Aldas, M., & López, J. (2017). On the Use of PLA-PHB Blends for Sustainable Food Packaging Applications. Materials, 10(9), 1008. doi:10.3390/ma10091008Aldas, M., Ferri, J. M., Lopez‐Martinez, J., Samper, M. D., & Arrieta, M. P. (2019). Effect of pine resin derivatives on the structural, thermal, and mechanical properties of Mater‐Bi type bioplastic. Journal of Applied Polymer Science, 137(4), 48236. doi:10.1002/app.48236Sessini, V., Navarro-Baena, I., Arrieta, M. P., Dominici, F., López, D., Torre, L., … Peponi, L. (2018). 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Properties and Applications of «Mater-Bi». Biodegradable Plastics and Polymers, 443-450. doi:10.1016/b978-0-444-81708-2.50049-xNainggolan, H., Gea, S., Bilotti, E., Peijs, T., & Hutagalung, S. D. (2013). Mechanical and thermal properties of bacterial-cellulose-fibre-reinforced Mater-Bi® bionanocomposite. Beilstein Journal of Nanotechnology, 4, 325-329. doi:10.3762/bjnano.4.37Ferri, J. M., Garcia-Garcia, D., Sánchez-Nacher, L., Fenollar, O., & Balart, R. (2016). The effect of maleinized linseed oil (MLO) on mechanical performance of poly(lactic acid)-thermoplastic starch (PLA-TPS) blends. Carbohydrate Polymers, 147, 60-68. doi:10.1016/j.carbpol.2016.03.082Morreale, M., Scaffaro, R., Maio, A., & La Mantia, F. P. (2008). Effect of adding wood flour to the physical properties of a biodegradable polymer. Composites Part A: Applied Science and Manufacturing, 39(3), 503-513. doi:10.1016/j.compositesa.2007.12.002Nayak, S. K. (2010). Biodegradable PBAT/Starch Nanocomposites. 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A., López, R., Mutke, S., Pinillos, F., & Gil, L. (2015). Influence of climate variables on resin yield and secretory structures in tapped Pinus pinaster Ait. in central Spain. Agricultural and Forest Meteorology, 202, 83-93. doi:10.1016/j.agrformet.2014.11.023Davis, G., & Song, J. H. (2006). Biodegradable packaging based on raw materials from crops and their impact on waste management. Industrial Crops and Products, 23(2), 147-161. doi:10.1016/j.indcrop.2005.05.004Yadav, B. K., Gidwani, B., & Vyas, A. (2015). Rosin: Recent advances and potential applications in novel drug delivery system. Journal of Bioactive and Compatible Polymers, 31(2), 111-126. doi:10.1177/0883911515601867Butt, H.-J., Cappella, B., & Kappl, M. (2005). Force measurements with the atomic force microscope: Technique, interpretation and applications. Surface Science Reports, 59(1-6), 1-152. doi:10.1016/j.surfrep.2005.08.003J. Roa, J., Rayon, E., Morales, M., & Segarra, M. (2012). Contact Mechanics at Nanometric Scale Using Nanoindentation Technique for Brittle and Ductile Materials. Recent Patents on Engineering, 6(2), 116-126. doi:10.2174/187221212801227130Hernández‐Fernández, J., Rayón, E., López, J., & Arrieta, M. P. (2019). Enhancing the Thermal Stability of Polypropylene by Blending with Low Amounts of Natural Antioxidants. Macromolecular Materials and Engineering, 304(11), 1900379. doi:10.1002/mame.201900379Taguet, A., Huneault, M. A., & Favis, B. D. (2009). Interface/morphology relationships in polymer blends with thermoplastic starch. Polymer, 50(24), 5733-5743. doi:10.1016/j.polymer.2009.09.055Zhang, S., He, Y., Lin, Z., Li, J., & Jiang, G. (2019). Effects of tartaric acid contents on phase homogeneity, morphology and properties of poly (butyleneadipate-co-terephthalate)/thermoplastic starch bio-composities. Polymer Testing, 76, 385-395. doi:10.1016/j.polymertesting.2019.04.005Mohammadi Nafchi, A., Moradpour, M., Saeidi, M., & Alias, A. K. (2013). Thermoplastic starches: Properties, challenges, and prospects. Starch - Stärke, 65(1-2), 61-72. doi:10.1002/star.201200201Van Soest, J. J. G., De Wit, D., & Vliegenthart, J. F. G. (1996). Mechanical properties of thermoplastic waxy maize starch. Journal of Applied Polymer Science, 61(11), 1927-1937. doi:10.1002/(sici)1097-4628(19960912)61:113.0.co;2-lZhang, Y., Rempel, C., & Liu, Q. (2014). Thermoplastic Starch Processing and Characteristics—A Review. Critical Reviews in Food Science and Nutrition, 54(10), 1353-1370. doi:10.1080/10408398.2011.636156Yu, J., Gao, J., & Lin, T. (1996). Biodegradable thermoplastic starch. Journal of Applied Polymer Science, 62(9), 1491-1494. doi:10.1002/(sici)1097-4628(19961128)62:93.0.co;2-1Zullo, R., & Iannace, S. (2009). The effects of different starch sources and plasticizers on film blowing of thermoplastic starch: Correlation among process, elongational properties and macromolecular structure. Carbohydrate Polymers, 77(2), 376-383. doi:10.1016/j.carbpol.2009.01.007Sousa, F. M., Costa, A. R. M., Reul, L. T. A., Cavalcanti, F. B., Carvalho, L. H., Almeida, T. G., & Canedo, E. L. (2018). Rheological and thermal characterization of PCL/PBAT blends. Polymer Bulletin, 76(3), 1573-1593. doi:10.1007/s00289-018-2428-5Mittal, V., Akhtar, T., Luckachan, G., & Matsko, N. (2014). PLA, TPS and PCL binary and ternary blends: structural characterization and time-dependent morphological changes. Colloid and Polymer Science, 293(2), 573-585. doi:10.1007/s00396-014-3458-7Arrieta, M. P., López, J., Hernández, A., & Rayón, E. (2014). Ternary PLA–PHB–Limonene blends intended for biodegradable food packaging applications. European Polymer Journal, 50, 255-270. doi:10.1016/j.eurpolymj.2013.11.009Burgos, N., Martino, V. P., & Jiménez, A. (2013). Characterization and ageing study of poly(lactic acid) films plasticized with oligomeric lactic acid. 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Microstructure, mechanical, and thermogravimetric characterization of cellulosic by-products obtained from biomass seeds

The microstructural, thermal, and nanomechanical characterization of biomass by-products coming from the food industry were studied. Scanning electron microscopy showed a microstructure formed by polygonal grains. The thermal behavior of seeds, evaluated by thermogravimetric analysis, revealed three main components (hemicellulose, cellulose, and lignin). Walnut shell showed the highest thermal stability and also the highest amount of lignin. The nanomechanical aspects were evaluated by nanoindentation. Samples with higher amount of cellulose presented minor modulus values. In accordance with the thermal stability, the highest modulus and hardness were observed in walnut. These by-products could be useful as reinforcement materials for biodegradable plastic industry.This work has been supported by the Spanish Ministry of Science and Innovation (MAT2011-28468-C02-02) and the Autonomous Government of Valencia (Spain) through the research program Geronimo Forteza (62/2010, 9 de Junio DOCV no 6291). M.P. Arrieta is granted by Santiago Grisolia program (GRISOLIA/2011/007).Rayón Encinas, E.; Ferrándiz Bou, S.; Rico Beneito, MI.; López Martínez, J.; Arrieta, MP. (2015). Microstructure, mechanical, and thermogravimetric characterization of cellulosic by-products obtained from biomass seeds. International Journal of Food Properties. 18(6):1211-1222. https://doi.org/10.1080/10942912.2014.884578S1211122218

Innovative solutions and challenges to increase the use of poly(3-hydroxybutyrate) in food packaging and disposables

[EN] Poly(3-hydroxybutyrate) (PHB) has gain in recent years a huge interest in the food packaging field due to its renewable origin from waste as well as non-food crops, high mechanical strength, medium-to-high barrier performance, and inherent biodegradability in natural environments. Despite these advantages, PHB also shows a narrow processing window and high brittleness since this homopolyester shows low thermal stability and high crystallinity, limiting its industrial application. The present review provides an updated state of the art of the most relevant aspects in terms of processing and properties of PHB materials with a particular emphasis for their use in sustainable food packaging. It also describes the most potential strategies that can be applied to improve both the processability and mechanical properties of PHB, including the melt blending with green plasticizers and flexible biodegradable polymers as well as the development of more ductile co-polyesters. Finally, the waste management of the newly developed PHB-based articles is discussed, from their potential compostability to develop more biopolymers to more economically favored alternatives such as mechanical and chemical recycling technologies.This work was funded by the Spanish Ministry of Science and Innovation (MICINN, Spain), grant PID2021-123753NA-C32 funded by MCIN/AEI/10.13039/501100011033 and by "ERDF A way of making Europe", by the "European Union"; Comunidad de Madrid (Spain) by CIRCULAGROPLAST, a research Project that has been funded by the Comunidad de Madrid through the call Research Grants for Young Investigators from Universidad Politécnica de Madrid; as well as by the Generalitat Valenciana (Spain) through the BEST Program (CIBEST/2021/94). S. Torres-Giner acknowledges the Spanish Ministry of Science and Innovation (MICINN, Spain) for his Ramón y Cajal contract (RYC2019-027784-I).Garcia-Garcia, D.; Quiles-Carrillo, L.; Balart, R.; Torres-Giner, S.; Arrieta, MP. (2022). Innovative solutions and challenges to increase the use of poly(3-hydroxybutyrate) in food packaging and disposables. European Polymer Journal. 178:1-20. https://doi.org/10.1016/j.eurpolymj.2022.11150512017

Degradation of a mechanically recycled polylactide/halloysite nanocomposite in an ethanolic food simulant

[EN] This work aims to study the effect of immersion in a ethanolic food simulant in mechanically recycled poly(lactic acid) (PLAR) and its nanocomposites reinforced with halloysite nanotubes (HNT). PLAR was obtained by subjecting PLA to an accelerated ageing process, which includes photochemical, thermal and hydrothermal ageing steps, followed by a final demanding washing step. PLAR was further reinforced with 4 %wt. HNT to improve the properties of the PLAR films. The materials were melt compounded by melt extrusion and processed into films by compression molding. The resulting films were exposed to food simulant D1 (50 %vol. ethanol solution) for 10 days at 40 °C. The intrinsic viscosity, crystallization behavior, thermal stability as well as the mechanical performance were analyzed before and after the contact with the food simulant. The swelling, plasticizing and hydrolyzing effect of the food simulant led to an important decrease of the intrinsic viscosity of all the samples, along with a significant increase of the crystallinity. Thermal stability was negatively affected by the decrease of the molecular weight, while the high crystallinity values resulted in materials with higher Vickers hardness values after the immersion in the food simulant.This work was supported by European Union’s Horizon 2020 research and innovation program [grant agreement No. 860407 BIO-PLASTICS EUROPE], by MINECO-Spain [project CTM2017-88989-P] as well as Universidad Politécnica de Madrid [project UPM RP 160543006].Beltrán, FR.; Arrieta, MP.; Hortal, Y.; Gaspar, G.; De La Orden, MU.; Martínez Urreaga, J. (2021). Degradation of a mechanically recycled polylactide/halloysite nanocomposite in an ethanolic food simulant. Journal of Applied Research in Technology & Engineering. 2(2):63-70. https://doi.org/10.4995/jarte.2021.15297OJS637022Agüero, A., Morcillo, D.M., Quiles-Carrillo, L., Balart, R., Boronat, T., Lascano, D., & Fenollar, O. (2019). Study of the influence of the reprocessing cycles on the final properties of polylactide pieces obtained by injection molding. Polymers, 11(12), 1908. https://doi.org/10.3390/polym11121908Arrieta, M.P., Castro-López, M., Rayón, E., Barral-Losada, L., López-Vilariño, J.M., López, J., & González-Rodríguez, M.V. (2014). Plasticized poly(lactic acid)-Poly(hydroxybutyrate) (PLA-PHB) blends incorporated with catechin intended for active food-packaging applications. Journal of Agricultural and Food Chemistry, 62(41), 10170-10180. https://doi.org/10.1021/jf5029812Arrieta, P.M., Samper, D.M., Aldas, M., & López, J. (2017). On the use of PLA-PHB blends for sustainable food packaging applications. Materials, 10(9), 1008. https://doi.org/10.3390/ma10091008Badia, J.D., Santonja-Blasco, L., Martínez-Felipe, A., & Ribes-Greus, A. (2012). Hygrothermal ageing of reprocessed polylactide. Polymer Degradation and Stability, 97(10), 1881-1890. https://doi.org/10.1016/j.polymdegradstab.2012.06.001Beltrán, F.R., de la Orden, M.U., Lorenzo, V., Pérez, E., Cerrada, M.L., & Martínez Urreaga, J. (2016). Water-induced structural changes in poly(lactic acid) and PLLA-clay nanocomposites. Polymer, 107, 211-222. https://doi.org/10.1016/j.polymer.2016.11.031Beltrán, F.R., Lorenzo, V., Acosta, J., de la Orden, M.U., & Martínez Urreaga, J. (2018a). Effect of simulated mechanical recycling processes on the structure and properties of poly(lactic acid). Journal of Environmental Management, 216, 25-31. https://doi.org/10.1016/j.jenvman.2017.05.020Beltrán, F.R., de la Orden, M.U., & Martínez Urreaga, J. (2018b). Amino-modified halloysite nanotubes to reduce polymer degradation and improve the performance of mechanically recycled poly(lactic acid). Journal of Polymers and the Environment, 26, 4046-4055. https://doi.org/10.1007/s10924-018-1276-6Beltrán, F.R., Climent-Pascual, E., de la Orden, M.U., & Martínez Urreaga, J. (2020). Effect of solid-state polymerization on the structure and properties of mechanically recycled poly(lactic acid). Polymer Degradation and Stability, 171, 109045. https://doi.org/10.1016/j.polymdegradstab.2019.109045Castro-Aguirre, E., Iñiguez-Franco, F., Samsudin, H., Fang, X., & Auras, R. (2016). Poly(lactic acid)-Mass production, processing, industrial applications, and end of life. Advanced Drug Delivery Reviews, 107, 333-366. https://doi.org/10.1016/j.addr.2016.03.010Cosate de Andrade, M.F., Souza, P.M.S., Cavalett, O., & Morales, A.R. (2016). Life cycle assessment of poly(lactic acid) (PLA): Comparison between chemical recycling, mechanical recycling and composting. Journal of Polymers and the Environment, 24(4), 372-384. https://doi.org/10.1007/s10924-016-0787-2European Bioplastics. (2020). Bioplastics market data 2019. https://www.european-bioplastics.org/market/.European Comission. (2018). A european strategy for plastics in a circular economy. Available at https://ec.europa.eu/environment/circular-economy/pdf/plastics-strategy-brochure.pdfEuropean Comission. (2019). Directive (EU) 2019/904 of the European Parliament and of the Council of 5 June 2019 on the reduction of the impact of certain plastic products on the environment.Farah, S., Anderson, D.G., & Langer, R. (2016). Physical and mechanical properties of PLA, and their functions in widespread applications - A comprehensive review. Advanced Drug Delivery Reviews, 107, 367-392. https://doi.org/10.1016/j.addr.2016.06.012Fortunati, E., Peltzer, M., Armentano, I., Torre, L., Jiménez, A., & Kenny, J.M. (2012). Effects of modified cellulose nanocrystals on the barrier and migration properties of PLA nano-biocomposites. Carbohydrate Polymers, 90(2), 948-956. https://doi.org/10.1016/j.carbpol.2012.06.025Haider, T., Völker, C., Kramm, J., Landfester, K., & Wurm, F.R. (2018). Plastics of the future? the impact of biodegradable polymers on the environment and on society. Angewandte Chemie International Edition, 58(1), 50-62. https://doi.org/10.1002/anie.201805766Iñiguez-Franco, F., Auras, R., Burgess, G., Holmes, D., Fang, X., Rubino, M., & Soto-Valdez, H. (2016). Concurrent solvent induced crystallization and hydrolytic degradation of PLA by water-ethanol solutions. Polymer, 99, 315-323. https://doi.org/10.1016/j.polymer.2016.07.018Iñiguez-Franco, F., Auras, R., Rubino, M., Dolan, K., Soto-Valdez, H., & Selke, S. (2017). Effect of nanoparticles on the hydrolytic degradation of PLA-nanocomposites by water-ethanol solutions. Polymer Degradation and Stability, 146, 287-297. https://doi.org/10.1016/j.polymdegradstab.2017.11.004Kale, G., Auras, R., & Singh, S.P. (2007). Comparison of the degradability of poly(lactide) packages in composting and ambient exposure conditions. Packaging Technology and Science, 20(1), 49-70. https://doi.org/10.1002/pts.742Liu, M., Guo, B., Zou, Q., Du, M., & Jia, D. (2008). Interactions between halloysite nanotubes and 2,5-bis(2-benzoxazolyl) thiophene and their effects on reinforcement of polypropylene/halloysite nanocomposites. Nanotechnology, 19(20), 205709. https://doi.org/10.1088/0957-4484/19/20/205709Maga, D., Hiebel, M., & Thonemann, N. (2019). Life cycle assessment of recycling options for polylactic acid. Resources, Conservation and Recycling, 149, 86-96 https://doi.org/10.1016/j.resconrec.2019.05.018Meaurio, E., López-Rodríguez, N., & Sarasua, J.R. (2006). Infrared spectrum of poly(l-lactide): Application to crystallinity studies. Macromolecules, 39(26), 9291-9301. https://doi.org/10.1021/ma061890rNiaounakis, M. (2019). Recycling of biopolymers - the patent perspective. European Polymer Journal, 114, 464-475 https://doi.org/10.1016/j.eurpolymj.2019.02.027Perego, G., Cella, G. D., & Bastioli, C. (1996). Effect of molecular weight and crystallinity on poly(lactic acid) mechanical properties. Journal of Applied Polymer Science, 59(1), 37-43. https://doi.org/10.1002/(SICI)1097-4628(19960103)59:13.0.CO;2-NRaquez, J., Habibi, Y., Murariu, M., & Dubois, P. (2013). Polylactide (PLA)-based nanocomposites. Progress in Polymer Science, 38(10-11), 1504-1542. https://doi.org/10.1016/j.progpolymsci.2013.05.014Risyon, N.P., Othman, S.H., Basha, R.K., & Talib, R.A. (2020). Characterization of polylactic acid/halloysite nanotubes bionanocomposite films for food packaging. Food Packaging and Shelf Life, 23, 100450 https://doi.org/10.1016/j. fpsl.2019.100450Rojas-Lema, S., Quiles-Carrillo, L., Garcia-Garcia, D., Melendez-Rodriguez, B., Balart, R., & Torres-Giner, S. (2020). Tailoring the properties of thermo-compressed polylactide films for food packaging applications by individual and combined additions of lactic acid oligomer and halloysite nanotubes. Molecules, 25(8), 1976. https://doi.org/10.3390/ molecules25081976Rossi, V., Cleeve-Edwards, N., Lundquist, L., Schenker, U., Dubois, C., Humbert, S., & Jolliet, O. (2015). Life cycle assessment of end-of-life options for two biodegradable packaging materials: Sound application of the European waste hierarchy. Journal of Cleaner Production, 86, 132-145. https://doi.org/10.1016/j.jclepro.2014.08.049Samper, M.D., Arrieta, M.P., Ferrándiz, S., & López, J. (2014). Influence of biodegradable materials in the recycled polystyrene. Journal of Applied Polymer Science, 131(23), 41161. https://doi.org/10.1002/app.41161Samper, M.D., Bertomeu, D., Arrieta, M.P., Ferri, J.M., & López-Martínez, J. (2018). Interference of biodegradable plastics in the polypropylene recycling process. Materials, 11(10), 1886. https://doi.org/10.3390/ma11101886Tuna, B., & Ozkoc, G. (2017). Effects of diisocyanate and polymeric epoxidized chain extenders on the properties of recycled poly(lactic acid). Journal of Polymers and the Environment, 25, 983-993. https://doi.org/10.1007/s10924-016-0856-6Villegas, C., Arrieta, M.P., Rojas, A., Torres, A., Faba, S., Toledo, M.J., ..., & Valenzuela, X. (2019). PLA/organoclay bionanocomposites impregnated with thymol and cinnamaldehyde by supercritical impregnation for active and sustainable food packaging. Composites Part B: Engineering, 176, 107336. https://doi.org/10.1016/j.compositesb.2019.10733

Thermally-activated shape memory effect on biodegradable nanocomposites based on PLA/PCL blend reinforced with hydroxyapatite

[EN] In this work, the effect of the addition of different amount of nanosized hydroxyapatite (nHA) on the shape memory behavior of blends based on poly (lactic acid) (PLA) and poly (epsilon-caprolactone) (PCL) has been studied. In particular PLA/PCL blend with 70 wt % PLA has been reinforced with 0.5, 1 and 3 wt % nHA. Moreover, the relationship between the morphology and the final properties of the nanocomposites has been investigated by field emission scanning electron microscopy, confocal Raman spectroscopy and atomic force microscopy. In particular, PeakForce has been used to study quantitative nanomechanical properties of the multifunctional materials leading to conclusion that nHA increase the phase separation between PLA and PCL as well as act as reinforcements for the PCL-rich phase of the nanocomposites. Furthermore, excellent thermally-activated shape memory response has been obtained for all the nanocomposites at 55 degrees C. Finally, the disintegration under composting conditions at laboratory scale level was studied in order to confirm the biodegradable character of these nanocomposites. Indeed, these materials are able to be used for biomedical issues as well as for packaging applications where both thermally-activated shape memory effect and biodegradability are requested.Authors thank the Spanish Ministry of Economy, Industry and Competitiveness, MINEICO, (MAT2017-88123-P) and the Regional Government of Madrid (S2013/MIT-2862) for the economic support. M.P.A. and L.P. acknowledge the Juan de la Cierva (FJCI-2014-20630) and Ramon y Cajal (RYC-2014-15595) contracts from the MINEICO, respectively. The authors also thanks CSIC for the I-Link project (I-Link1149).Peponi, L.; Sessini, V.; Arrieta, MP.; Navarro-Baena, I.; Sonseca Olalla, Á.; Dominici, F.; Giménez Torres, E.... (2018). Thermally-activated shape memory effect on biodegradable nanocomposites based on PLA/PCL blend reinforced with hydroxyapatite. Polymer Degradation and Stability. 151:36-51. https://doi.org/10.1016/j.polymdegradstab.2018.02.019S365115

Oxygen reduction using a metal-free naphthalene diimide-based covalent organic framework electrocatalyst

A novel naphthalene diimide-based covalent organic framework (NDI-COF) has been synthesized and successfully exfoliated into COF nanosheets (CONs). Electrochemical measurements reveal that the naphthalene diimide units incorporated into NDI-CONs act as efficient electrocatalyst for oxygen reduction in alkaline media, showing its potential for the development of metal-free fuel cellsFinancial support from the Spanish Government (projects MAT2016-77608-C3-1-P, MAT2016-77608-C3-2-P, CTQ2017-84309-C2-1-R, MAT2017-85089-C2-1-R, FJCI-2017-33536 and RYC-2015-17730), the UCM (INV.GR.00.1819.10759) and the Madrid Regional Government (TRANSNANOAVANSENS-CM (S2018/NMT-4349)) is acknowledge

Characterization of PLA-limonene blends for food packaging applications

Polymers derived from renewable resources are now considered as promising alternatives to traditional petro-polymers as they mitigate current environmental concerns (raw renewable materials/biodegradability). D-limonene can be found in a variety of citrus, indeed is the main component of citrus oils and one of most important contributors to citrus flavor. The incorporation of limonene in PLA matrix was evaluated and quantified by Pyrolysis Gas Chromatography Mass Spectrometry (Py-GC/MS). Transparent films were obtained after the addition of the natural compound. Mechanical properties were evaluated by tensile tests. The effect of limonene on mechanical properties of PLA films was characterized by an increase in the elongation at break and a decrease in the elastic modulus. The fracture surface structure of films was evaluated by scanning electron microscopy (SEM), and homogeneous surfaces were observed in all cases. Barrier properties were reduced due to the increase of the chain mobility produced by the D-limonene. (C) 2013 Elsevier Ltd. All rights reserved.This research was supported by the Ministry of Science and Innovation of Spain (MAT2011-28468-C02-02). Marina P. Arrieta thanks Generalitat Valenciana (Spain) for a Santiago Grisolia Fellowship. Authors thank Professor Alfonso Jimenez from the University of Alicante, for his useful discussions.Arrieta, MP.; López Martínez, J.; Ferrándiz Bou, S.; Peltzer, MA. (2013). Characterization of PLA-limonene blends for food packaging applications. Polymer Testing. 32(4):760-768. https://doi.org/10.1016/j.polymertesting.2013.03.016S76076832

Functional properties of sodium and calcium caseinate antimicrobial active films containing carvacrol

Active edible films were prepared by adding carvacrol into sodium caseinate (SC) and calcium caseinate (CC) matrices plasticized with two different glycerol concentrations (25 and 35 wt%) prepared by solvent casting. Functional characterisation of these bio-films was carried out by determination of some of their physico-chemical properties, such as colour, transparency, oxygen barrier, wettability, dye permeation properties and antibacterial effectiveness against Gram negative and Gram positive bacteria. All films exhibited good performance in terms of optical properties in the CIELab space showing high transparency. Carvacrol was able to reduce CC oxygen permeability and slightly increased the surface hydrophobicity. Dye diffusion experiments were performed to evaluate permeation properties. The diffusion of dye through films revealed that SC was more permeable than CC. The agar diffusion method was used for the evaluation of the films antimicrobial effectiveness against Escherichia cell and Staphylococcus aureus. Both SC and CC edible films with carvacrol showed inhibitory effects on both bacteria. (C) 2013 Elsevier Ltd. All rights reserved.This research was supported by the Ministry of Science and Innovation of Spain through the projects MAT2011-28468-C02-01, MAT2011-28468-C02-02 and HP2008-0080. M.P. Arrieta thanks Fundacion MAPFRE for "Ignacio Hernando de Larramendi 2009-Medio Ambiente" fellowship (MAPFRE-IHL-01). Authors thank Ferrer Alimentacion S.A., for providing the caseinates powders.Arrieta, MP.; Peltzer, MA.; López Martínez, J.; Garrigós Selva, MDC.; Valente, AJM.; Jimenez Migallon, A. (2014). Functional properties of sodium and calcium caseinate antimicrobial active films containing carvacrol. Journal of Food Engineering. 121:94-101. https://doi.org/10.1016/j.jfoodeng.2013.08.015S9410112

Nucleation and crystallization in bio-based immiscible polyester blends

Bio-based thermoplastic polyesters are highly promising materials as they combine interesting thermal and physical properties and in many cases biodegradability. However, sometimes the best property balance can only be achieved by blending in order to improve barrier properties, biodegradability or mechanical properties. Nucleation, crystallization and morphology are key factors that can dominate all these properties in crystallizable biobased polyesters. Therefore, their understanding, prediction and tailoring is essential. In this work, after a brief introduction about immiscible polymer blends, we summarize the crystallization behavior of the most important bio-based (and immiscible) polyester blends, considering examples of double-crystalline components. Even though in some specific blends (e.g., polylactide/polycaprolactone) many efforts have been made to understand the influence of blending on the nucleation, crystallization and morphology of the parent components, there are still many points that have yet to be understood. In the case of other immiscible polyester blends systems, the literature is scarce, opening up opportunities in this environmentally important research topic.The authors would like to acknowledge funding by the BIODEST project ((RISE) H2020-MSCA-RISE-2017-778092