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Morselli D, Cataldi P, Paul UC, Ceseracciu L, Benitez JJ, Scarpellini A, Guzman-Puyol S, Heredia A, Valentini P, Pompa PP, Marrero-López D, Athanassiou A, Heredia-Guerrero JA. Zinc Polyaleuritate Ionomer Coatings as a Sustainable, Alternative Technology for Bisphenol A-Free Metal Packaging. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2021; 9:15484-15495. [PMID: 34840919 PMCID: PMC8611806 DOI: 10.1021/acssuschemeng.1c04815] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 10/25/2021] [Indexed: 06/13/2023]
Abstract
Sustainable coatings for metal food packaging were prepared from ZnO nanoparticles (obtained by the thermal decomposition of zinc acetate) and a naturally occurring polyhydroxylated fatty acid named aleuritic (or 9,10,16-trihydroxyhexadecanoic) acid. Both components reacted, originating under specific conditions zinc polyaleuritate ionomers. The polymerization of aleuritic acid into polyaleuritate by a solvent-free, melt polycondensation reaction was investigated at different times (15, 30, 45, and 60 min), temperatures (140, 160, 180, and 200 °C), and proportions of zinc oxide and aleuritic acid (0:100, 5:95, 10:90, and 50:50, w/w). Kinetic rate constants calculated by infrared spectroscopy decreased with the amount of Zn due to the consumption of reactive carboxyl groups, while the activation energy of the polymerization decreased as a consequence of the catalyst effect of the metal. The adhesion and hardness of coatings were determined from scratch tests, obtaining values similar to robust polymers with high adherence. Water contact angles were typical of hydrophobic materials with values ≥94°. Both mechanical properties and wettability were better than those of bisphenol A (BPA)-based resins and most likely are related to the low migration values determined using a hydrophilic food simulant. The presence of zinc provided a certain degree of antibacterial properties. The performance of the coatings against corrosion was studied by electrochemical impedance spectroscopy at different immersion times in an aqueous solution of NaCl. Considering the features of these biobased lacquers, they can be potential materials for bisphenol A-free metal packaging.
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Affiliation(s)
- Davide Morselli
- Smart
Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
- Department
of Civil, Chemical, Environmental and Materials Engineering (DICAM), Università di Bologna, Via Terracini 28, 40131 Bologna, Italy
| | - Pietro Cataldi
- Smart
Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
- Center
for Nano Science and Technology@PoliMi, Istituto Italiano di Tecnologia, Via G. Pascoli 70/3, 20133 Milan, Italy
| | - Uttam Chandra Paul
- Smart
Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Luca Ceseracciu
- Materials
Characterization Facility, Istituto Italiano
di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Jose Jesus Benitez
- Instituto
de Ciencia de Materiales de Sevilla, Centro Mixto CSIC-Universidad
de Sevilla, Americo Vespucio
49, Isla de la Cartuja, Sevilla 41092, Spain
| | - Alice Scarpellini
- Electron
Microscopy Facility, Istituto Italiano di
Tecnologia, Via Morego, 30, Genova 16163, Italy
| | - Susana Guzman-Puyol
- Smart
Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
- Instituto
de Hortofruticultura Subtropical y Mediterránea “La
Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones
Científicas (IHSM, UMA-CSIC), Bulevar Louis Pasteur, 49, 29010 Málaga, Spain
| | - Antonio Heredia
- Departamento
de Biología Molecular y Bioquímica, Facultad de Ciencias, Instituto de Hortofruticultura Subtropical y Mediterránea
“La Mayora”, Universidad de Málaga-Consejo Superior
de Investigaciones Científicas (IHSM, UMA-CSIC), E-29071 Málaga, Spain
| | - Paola Valentini
- Nanobiointeractions
& Nanodiagnostic, Istituto Italiano
di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - Pier Paolo Pompa
- Nanobiointeractions
& Nanodiagnostic, Istituto Italiano
di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | | | | | - José Alejandro Heredia-Guerrero
- Smart
Materials, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
- Instituto
de Hortofruticultura Subtropical y Mediterránea “La
Mayora”, Universidad de Málaga-Consejo Superior de Investigaciones
Científicas (IHSM, UMA-CSIC), Bulevar Louis Pasteur, 49, 29010 Málaga, Spain
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Benítez JJ, Guzman-Puyol S, Cruz-Carrillo MA, Ceseracciu L, González Moreno A, Heredia A, Heredia-Guerrero JA. Insoluble and Thermostable Polyhydroxyesters From a Renewable Natural Occurring Polyhydroxylated Fatty Acid. Front Chem 2019; 7:643. [PMID: 31616655 PMCID: PMC6768952 DOI: 10.3389/fchem.2019.00643] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Accepted: 09/09/2019] [Indexed: 01/02/2023] Open
Abstract
To explore the potential of long chain polyhydroxyalkanoates as non-toxic food packaging materials, the characterization of polyesters prepared from a natural occurring polyhydroxylated C16 carboxylic acid (9,10,16-trihydroxyhexadecanoic or aleuritic acid) has been addressed. Such monomer has been selected to elucidate the reactivity of primary and secondary hydroxyl groups and their contribution to the structure and properties of the polyester. Resulting polyaleuritate films have been produced using an open mold in one-step, solvent-free self-polycondensation in melt state and directly in air to evaluate the effect of oxygen in their final physical and chemical properties. These polymers are amorphous, insoluble, and thermostable, being therefore suitable for solvent, and heat resistant barrier materials. Structurally, most of primary hydroxyls are involved in ester bonds, but there is some branching arising from the partial participation of secondary O-H groups. The oxidative cleavage of the vicinal diol moiety and a subsequent secondary esterification had a noticeable effect on the amorphization and stiffening of the polyester by branching and densification of the ester bond network. A derivation of such structural modification was the surface compaction and the reduction of permeability to water molecules. The addition of Ti(OiPr)4 as a catalyst had a moderate effect, likely because of a poor diffusion within the melt, but noticeably accelerated both the secondary esterification and the oxidative processes. Primary esterification was a high conversion bulk reaction while oxidation and secondary esterification was restricted to nearby regions of the air exposed side of cast films. The reason was a progressive hindering of oxygen diffusion as the reaction progresses and a self-regulation of the altered layer growth. Despite such a reduced extent, the oxidized layer noticeably increased the UV-vis light blockage capacity. In general, characterized physical properties suggest a high potential of these polyaleuritate polyesters as food preserving materials.
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Affiliation(s)
- José Jesús Benítez
- Instituto de Ciencia de Materiales de Sevilla, Centro Mixto CSIC-Universidad de Sevilla, Seville, Spain
| | - Susana Guzman-Puyol
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Departamento de Biología Molecular y Bioquímica, Universidad de Málaga, Málaga, Spain.,Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-CSIC, Málaga, Spain
| | | | - Luca Ceseracciu
- Materials Characterization Facility, Istituto Italiano di Tecnologia, Genova, Italy
| | - Ana González Moreno
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Departamento de Biología Molecular y Bioquímica, Universidad de Málaga, Málaga, Spain
| | - Antonio Heredia
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Departamento de Biología Molecular y Bioquímica, Universidad de Málaga, Málaga, Spain.,Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-CSIC, Málaga, Spain
| | - José Alejandro Heredia-Guerrero
- Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Departamento de Biología Molecular y Bioquímica, Universidad de Málaga, Málaga, Spain.,Instituto de Hortofruticultura Subtropical y Mediterránea La Mayora, Universidad de Málaga-CSIC, Málaga, Spain
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