Polymers for Packaging Applications

A special issue of Polymers (ISSN 2073-4360).

Deadline for manuscript submissions: closed (15 June 2018) | Viewed by 68936

Special Issue Editor


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Guest Editor
Department of Chemical Sciences, Università degli Studi di Catania, 95125 Catania, Italy
Interests: packaging materials; bio-based and biodegradable polymers; bio-based and biodegradable polyesters; green composites; polymerization of biopolymers; processing of bioplastics; sustainable polymer for food preservation; biopolymers for food packaging; edible films; compostable packaging; monomers from renewable resources; polymers from renewable resources; gas barrier properties; life cycle assessment (LCA) study; bioeconomy; circular economy
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Special Issue Information

Dear Colleagues,

Today, plastics cover up to 50% of primary packaging thanks to their positive features such as being lightweight, their flexibility, strength, transparency, impermeability, ease of sterilization, and so on. The low cost, their easy manufacturing and their great resistance to physical ageing and biological degradation are the keys to this success. However, this massive consumption is accompanied by consistent waste generation with an important environmental footprint. Taking into consideration that over 30% of plastics wastes are land-filled, the use of bioplastics could be considered as a sustainable alternative.

A great and growing interest in sustainability is so driving the development of "biobased" packaging materials, i.e., obtainable from renewable sources, which could be, or not, biodegradable and that are characterized by minimum waste production, transport efficiency and controlled after-use disposal and/or recycling.

Taking into consideration that aromatic polyesters like poly(ethylene terephthalate) (PET) and aliphatic polyolefins like polyehylene (PE) and polypropylene (PP) dominate the packaging scene, due to their competitive chemical–physical, barrier and mechanical performance-to-cost ratio, the interest of researchers and industry versus new biobased polymers. Considering the actual scenario, in particular, academic as well as industrial interest is oriented to finding bio-source alternatives to produce them, reducing petroleum dependence and carbon dioxide emissions.

This Special Issue will aim to discuss new packaging solutions, with an ultimate goal of denoting weaknesses and opportunities to improve sustainability efficiency in the packaging sector.

In particular, bio-based polymers obtained from renewable resources are driving ambitions to replace conventional packaging materials, coming from non-renewable resources, in order to reach a more sustainable development of the packaging industry.

This Special Issue will give a chance to the academic, as well as industrial, world to present an overview of novel polymers for packaging applications, focusing attention on their mechanical, chemical–physical, morphological and gas barrier performances, in order to establish a structure–property relationship. Mechanisms and pathways of polymer degradation will also be taken into consideration. These new smart plastics will be compared to traditional ones, which are extensively employed in the food packaging sector.

Research papers, as well as reviews, are welcome.

Prof. Dr. Valentina Siracusa
Guest Editor

Manuscript Submission Information

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Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Polymers is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2700 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

  • Packaging

  • Food Packaging

  • Plastics

  • Synthetic Polymers

  • Biodegradable Polymers

  • Natural bio-polymers

  • Synthetic bio-polymers

  • Polymers from renewable resources

  • Polymers from food waste

  • Polymer blends

  • Packaging with sustainable features

  • Polyesters

  • Bio-polyesters

  • Furanoates

  • Succinic acid

  • Poly(lactic acid)

  • Barrier properties

  • Polymer degradation

Published Papers (12 papers)

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Research

11 pages, 5794 KiB  
Article
High Pressure Treatment for Improving Water Vapour Barrier Properties of Poly(lactic acid)/Ag Nanocomposite Films
by Hai Chi, Jing Xue, Cheng Zhang, Haiyan Chen, Lin Li and Yuyue Qin
Polymers 2018, 10(9), 1011; https://doi.org/10.3390/polym10091011 - 11 Sep 2018
Cited by 30 | Viewed by 3659
Abstract
Effects of high pressure treatment (0, 200 and 400 MPa) on water vapour barrier, microstructure, thermal, and mechanical properties of poly (lactic acid) (PLA)/Ag nanocomposite films were investigated. The migration behavior of nano-Ag from the nanocomposite films in the presence of 50% ( [...] Read more.
Effects of high pressure treatment (0, 200 and 400 MPa) on water vapour barrier, microstructure, thermal, and mechanical properties of poly (lactic acid) (PLA)/Ag nanocomposite films were investigated. The migration behavior of nano-Ag from the nanocomposite films in the presence of 50% (v/v) ethanol as a food simulant was also studied. The water vapour barrier properties increased as pressure was applied to film-forming solutions. High pressure treatment enhanced the mutual effect between PLA and nanoparticles, leading to a more compact network structure in PLA/Ag nanocomposite films. Furthermore, PLA/Ag nanocomposite films treated by high pressure were significantly affected by microstructure, thermal, and mechanical properties when, compared with untreated samples. High pressure treatment at 200 to 400 MPa significantly (p < 0.05) reduced the migration of nano-Ag from the films. Overall, high pressure treatment on film-forming solutions showed potential in improving the functional properties of nanocomposite films, especially in relation to water vapour barrier properties. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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14 pages, 7264 KiB  
Article
Structural Evolution of Two-Phase Blends of Polycarbonate and PMMA by Simultaneous Biaxial Stretching
by Takumi Kobayashi and Hiromu Saito
Polymers 2018, 10(9), 950; https://doi.org/10.3390/polym10090950 - 27 Aug 2018
Cited by 7 | Viewed by 4930
Abstract
We investigated the structural evolution of the two-phase blends of polycarbonate (PC) and poly(methyl methacrylate) (PMMA) at various blend compositions by simultaneous biaxial stretching, using optical microscopy and SEM observation. The spherical PMMA domains and PC matrix of 30/70 PC/PMMA were enlarged uniformly [...] Read more.
We investigated the structural evolution of the two-phase blends of polycarbonate (PC) and poly(methyl methacrylate) (PMMA) at various blend compositions by simultaneous biaxial stretching, using optical microscopy and SEM observation. The spherical PMMA domains and PC matrix of 30/70 PC/PMMA were enlarged uniformly at the all in-plane direction, while the anisotropic-shaped co-continuous structure in 50/50 PC/PMMA was deformed to a crosshatched structure by the in-plane bimodal orientation. In 70/30 PC/PMMA, the phase inversion was found to occur by simultaneous biaxial stretching; that is, the spherical PMMA domains were changed to a crosshatched matrix by the in-plane bimodal orientation due to coalescence of the PMMA domains during the stretching. Owing to the phase inversion, the surface hardness estimated by the pencil hardness test became harder, from 2B to 2H, increasing the strain from 1.0 to 2.0. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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17 pages, 4081 KiB  
Article
Novel Random Copolymers of Poly(butylene 1,4-cyclohexane dicarboxylate) with Outstanding Barrier Properties for Green and Sustainable Packaging: Content and Length of Aliphatic Side Chains as Efficient Tools to Tailor the Material’s Final Performance
by Giulia Guidotti, Michelina Soccio, Valentina Siracusa, Massimo Gazzano, Andrea Munari and Nadia Lotti
Polymers 2018, 10(8), 866; https://doi.org/10.3390/polym10080866 - 4 Aug 2018
Cited by 15 | Viewed by 3305
Abstract
The present paper describes the synthesis of novel bio-based poly(butylene 1,4-cyclohexane dicarboxylate)-containing random copolymers for sustainable and flexible packaging applications. On one side, the linear butylene moiety has been substituted by glycol subunits with alkyl pendant groups of different length. On the other [...] Read more.
The present paper describes the synthesis of novel bio-based poly(butylene 1,4-cyclohexane dicarboxylate)-containing random copolymers for sustainable and flexible packaging applications. On one side, the linear butylene moiety has been substituted by glycol subunits with alkyl pendant groups of different length. On the other side, copolymers with different cis/trans isomer ratio of cyclohexane rings have been synthesized. The prepared samples were subjected to molecular, thermal, diffractometric, and mechanical characterization. The barrier performances to O2, CO2, and N2 gases were also evaluated. The presence of side alkyl groups did not alter the thermal stability, whereas it significantly influences the formation of ordered phases that deeply affect the functional properties, mainly in terms of mechanical response and barrier performance. In particular, the final materials present higher flexibility and significantly improved barrier properties with respect to the homopolymer and most polymers widely employed for flexible packaging. The improvement due to copolymerization was more pronounced in the case of higher co-unit-containing copolymers and for the samples with cyclohexane rings in the trans conformation. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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16 pages, 1999 KiB  
Article
Characterization and Evaluation of Controlled Antimicrobial Release from Petrochemical (PU) and Biodegradable (PHB) Packaging
by Alexey Iordanskii, Anna Zhulkina, Anatoliy Olkhov, Sergey Fomin, Andrey Burkov and Mikhail Stilman
Polymers 2018, 10(8), 817; https://doi.org/10.3390/polym10080817 - 25 Jul 2018
Cited by 7 | Viewed by 3641
Abstract
The academic exploration and technology design of active packaging are coherently supplying innovative approaches for enhancing the quality and safety of food, as well as prolonging their shelf-life. With the object of comparison between two barrier materials, such as stable petrochemical polyurethane (PU), [...] Read more.
The academic exploration and technology design of active packaging are coherently supplying innovative approaches for enhancing the quality and safety of food, as well as prolonging their shelf-life. With the object of comparison between two barrier materials, such as stable petrochemical polyurethane (PU), (BASF), and biodegradable natural poly(3-hydroxybutyrate) (PHB), (Biomer Co., Krailling, Germany), the study of antibacterial agent release has been performed. For the characterization of polymer surface morphology and crystallinity, the scanning electron microscopy (SEM), atomic force microscopy (AFM) and differential scanning calorimetry (DSC) were used respectively. The antimicrobial activity of chlorhexidine digluconate (CHD) has been estimated by the Bauer–Kirby Disk Diffusion Test. It was shown that the kinetic release profiles of CHD, as the active agent, in both polymers, significantly differed due to the superposition of diffusion and surface degradation in poly(3-hydroxybutyrate) (PHB). To emphasize the special transport phenomena in polymer packaging, the diffusivity modeling was performed and the CHD diffusion coefficients for the plane films of PU and PHB were further compared. The benefit of active biodegradable packaging on the base of PHB is discussed. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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10 pages, 578 KiB  
Article
GC-MS Screening Analysis for the Identification of Potential Migrants in Plastic and Paper-Based Candy Wrappers
by Soraya Galmán Graíño, Raquel Sendón, Julia López Hernández and Ana Rodríguez-Bernaldo de Quirós
Polymers 2018, 10(7), 802; https://doi.org/10.3390/polym10070802 - 21 Jul 2018
Cited by 35 | Viewed by 8931
Abstract
Food packaging materials may be a potential source of contamination through the migration of components from the material into foodstuffs. Potential migrants can be known substances such as additives (e.g., plasticizers, stabilizers, antioxidants, etc.), monomers, and so on. However, they can also be [...] Read more.
Food packaging materials may be a potential source of contamination through the migration of components from the material into foodstuffs. Potential migrants can be known substances such as additives (e.g., plasticizers, stabilizers, antioxidants, etc.), monomers, and so on. However, they can also be unknown substances, which could be non-intentionally added substances (NIAS). In the present study, non-targeted analysis using mass spectrometry coupled to gas chromatography (GC-MS) for the identification of migrants in plastic and paper-based candy wrappers was performed. Samples were analyzed after extraction with acetonitrile. Numerous compounds including N-alkanes, phthalates, acetyl tributyl citrate, tributyl aconitate, bis(2-ethylhexyl) adipate, butylated hydroxytoluene, etc. were identified. Many of the compounds detected in plastic samples are not included in the positive list of the authorized substances. One non-intentionally added substance, 7,9-Di-tert-butyl-1-oxaspiro(4,5)deca-6-9-diene-2,8-dione, which has been reported as a degradation product of the antioxidant Irganox 1010, was found in several samples of both plastic and paper packaging. The proposed method was shown to be a useful approach for the identification of potential migrants in packaging samples. The toxicity of the compounds identified was estimated according to Cramer rules. Then, a second targeted analysis was also conducted in order to identify photoinitiators; among the analyzed compounds, only 2-hydroxybenzophenone was found in five samples. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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12 pages, 3850 KiB  
Article
Ball-Milled Recycled Lead-Graphite Pencils as Highly Stretchable and Low-Cost Thermal-Interface Materials
by Chun-An Liao, Yee-Kwan Kwan, Tien-Chan Chang and Yiin-Kuen Fuh
Polymers 2018, 10(7), 799; https://doi.org/10.3390/polym10070799 - 20 Jul 2018
Cited by 7 | Viewed by 4268
Abstract
A simple and sustainable production of nanoplatelet graphite at low cost is presented using carbon-based materials, including the recycled lead-graphite pencils. In this work, exfoliated graphite nanoplatelets (EGNs), ball-milled exfoliated graphite nanoplatelets (BMEGNs) and recycled lead-graphite pencils (recycled 2B), as well as thermally [...] Read more.
A simple and sustainable production of nanoplatelet graphite at low cost is presented using carbon-based materials, including the recycled lead-graphite pencils. In this work, exfoliated graphite nanoplatelets (EGNs), ball-milled exfoliated graphite nanoplatelets (BMEGNs) and recycled lead-graphite pencils (recycled 2B), as well as thermally cured polydimethylsiloxane (PDMS), are used to fabricate highly stretchable thermal-interface materials (TIMs) with good thermally conductive and mechanically robust properties. Several characterization techniques including scanning electron microscopy (SEM) and thermogravimetric analysis (TGA) showed that recycled nanoplatelet graphite with lateral size of tens of micrometers can be reliably produced. Experimentally, the thermal conductivity was measured for EGNs, BMEGNs and recycled 2B fillers with/without the effect of ball milling. The in-plane thermal conductivities of 12.97 W/mK (EGN), 13.53 W/mK (recycled 2B) and 14.56 W/mK (BMEGN) and through-plane thermal conductivities of 0.76 W/mK (EGN), 0.84 W/mK (recycled 2B) and 0.95 W/mK (BMEGN) were experimentally measured. Anisotropies were calculated as 15.31, 15.98 and 16.95 for EGN, recycled 2B and BMEGN, respectively. In addition, the mechanical robustness of the developed TIMs is such that they are capable of repeatedly bending at 180 degrees with outstanding flexibility, including the low-cost renewable material of recycled lead-graphite pencils. For heat dissipating application in high-power electronics, the TIMs of recycled 2B are capable of effectively reducing temperatures to approximately 6.2 °C as favorably compared with thermal grease alone. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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14 pages, 2051 KiB  
Article
Poly(propylene 2,5-thiophenedicarboxylate) vs. Poly(propylene 2,5-furandicarboxylate): Two Examples of High Gas Barrier Bio-Based Polyesters
by Giulia Guidotti, Michelina Soccio, Nadia Lotti, Massimo Gazzano, Valentina Siracusa and Andrea Munari
Polymers 2018, 10(7), 785; https://doi.org/10.3390/polym10070785 - 17 Jul 2018
Cited by 74 | Viewed by 5383
Abstract
Both academia and industry are currently devoting many efforts to develop high gas barrier bioplastics as substitutes of traditional fossil-based polymers. In this view, this contribution presents a new biobased aromatic polyester, i.e., poly(propylene 2,5-thiophenedicarboxylate) (PPTF), which has been compared with the furan-based [...] Read more.
Both academia and industry are currently devoting many efforts to develop high gas barrier bioplastics as substitutes of traditional fossil-based polymers. In this view, this contribution presents a new biobased aromatic polyester, i.e., poly(propylene 2,5-thiophenedicarboxylate) (PPTF), which has been compared with the furan-based counterpart (PPF). Both biopolyesters have been characterized from the molecular, thermo-mechanical and structural points of view. Gas permeability behavior has been evaluated with respect to 100% oxygen, carbon dioxide and nitrogen at 23 °C. In case of CO2 gas test, gas transmission rate has been also measured at different temperatures. The permeability behavior at different relative humidity has been investigated for both biopolyesters, the thiophen-containing sample demonstrating to be better than the furan-containing counterpart. PPF’s permeability behavior became worse than PPTF’s with increasing RH, due to the more polar nature of the furan ring. Both biopolyesters under study are characterized by superior gas barrier performances with respect to PEF and PET. With the simple synthetic strategy adopted, the exceptional barrier properties render these new biobased polyesters interesting alternatives in the world of green and sustainable packaging materials. The different polarity and stability of heterocyclic rings was revealed to be an efficient tool to tailor the ability of crystallization, which in turn affects mechanical and barrier performances. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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10 pages, 4718 KiB  
Article
Enhanced Properties of Biodegradable Poly(Propylene Carbonate)/Polyvinyl Formal Blends by Melting Compounding
by Dongmei Han, Zhen Guo, Shou Chen, Min Xiao, Xiaohua Peng, Shuanjin Wang and Yuezhong Meng
Polymers 2018, 10(7), 771; https://doi.org/10.3390/polym10070771 - 13 Jul 2018
Cited by 10 | Viewed by 5139
Abstract
Polyvinyl formal (PVF) was first synthesized via the reaction of poly(vinyl alcohol) (PVA) and formaldehyde. The synthesized PVF exhibits a high decomposition temperature, glass transition temperature, and low melting point compared to pristine PVA. The synthesized PVF can be melt processed at temperatures [...] Read more.
Polyvinyl formal (PVF) was first synthesized via the reaction of poly(vinyl alcohol) (PVA) and formaldehyde. The synthesized PVF exhibits a high decomposition temperature, glass transition temperature, and low melting point compared to pristine PVA. The synthesized PVF can be melt processed at temperatures much lower than PVA. Poly(propylene carbonate) (PPC) and the as-made PVF were melt blended in a Haake mixer. The mechanical properties, thermal behaviors, and morphologies of PPC/PVF blends were investigated. Compared to the pure PPC, PPC/PVF blends show higher tensile strength and Vicat softening temperature. Thermogravimetric (TGA) result reveals that the thermal stabilities of PPC/PVF blends decreased with the increase of the content of PVF. Scanning electron microscopy (SEM) observation indicates that the interfacial compatibility of the PVF and PPC matrix is better than that of the PVA and PPC matrix. The PPC/PVF blends show much better comprehensive properties compared to pure commercial PPC, which provides a practical way to extend the application of PPC copolymer. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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22 pages, 30159 KiB  
Article
New Poly(lactic acid) Active Packaging Composite Films Incorporated with Fungal Melanin
by Łukasz Łopusiewicz, Filip Jędra and Małgorzata Mizielińska
Polymers 2018, 10(4), 386; https://doi.org/10.3390/polym10040386 - 1 Apr 2018
Cited by 74 | Viewed by 10079
Abstract
In this work, fungal melanin was used for the first time to prepare poly(lactic acid)-based composites. The films of various melanin concentrations (0.025%, 0.05% and 0.2% w/w) were prepared using an extrusion method. The mechanical, antioxidant, antimicrobial, water vapor and [...] Read more.
In this work, fungal melanin was used for the first time to prepare poly(lactic acid)-based composites. The films of various melanin concentrations (0.025%, 0.05% and 0.2% w/w) were prepared using an extrusion method. The mechanical, antioxidant, antimicrobial, water vapor and UV-Vis barrier properties, as well as available polyphenolics on the surface, were studied. FT-IR and Raman spectroscopy studies were carried out to analyze the chemical composition of the resulting films. The hydrophobicity, color response, thermal, optical properties, and opacity values were also determined. The results of this study show that the addition of fungal melanin to poly(lactic acid) (PLA) as a modifier influenced mechanical and water vapor barrier properties depending on melanin concentration. In low concentration, melanin enhanced the mechanical and barrier properties of the modified films, but in larger amounts, the properties were decreased. The UV-Vis barrier properties of PLA/melanin composites were marginally improved. Differential Scanning Calorimetry (DSC) analysis indicated that crystallinity of PLA increased by the addition of melanin, but this did not affect the thermal stability of the films. Modified PLA/melanin films showed good antioxidant activity and were active against Enterococcus faecalis, Pseudomonas aeruginosa and Pseudomonas putida. The addition of melanin caused changes in color values, decreasing lightness and increasing the redness and yellowness of films. Based on the results of this study, fungal melanin has good potential to be exploited as a value-added modifier that can improve the overall properties of PLA. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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16 pages, 2136 KiB  
Article
Preparation and Characterization of Poly(ether-block-amide)/Polyethylene Glycol Composite Films with Temperature-Dependent Permeation
by Sarinthip Thanakkasaranee, Dowan Kim and Jongchul Seo
Polymers 2018, 10(2), 225; https://doi.org/10.3390/polym10020225 - 24 Feb 2018
Cited by 50 | Viewed by 7278
Abstract
A series of poly(ether-block-amide) (PEBAX)/polyethylene glycol (PEG) composite films (PBXPG) were prepared by solution casting technique. This study demonstrates how the incorporation of different molecular weight PEG into PEBAX can improve the as-prepared composite film performance in gas permeability as a function of [...] Read more.
A series of poly(ether-block-amide) (PEBAX)/polyethylene glycol (PEG) composite films (PBXPG) were prepared by solution casting technique. This study demonstrates how the incorporation of different molecular weight PEG into PEBAX can improve the as-prepared composite film performance in gas permeability as a function of temperature. Additionally, we investigated the effect of PEG with different molecular weights on gas transport properties, morphologies, thermal properties, and water sorption. The thermal stability of the composite films increased with increasing molecular weight of PEG, whereas the water sorption and total surface energy decreased. As the temperature increased from 10 to 80 °C, the low (L)-PBXPG and medium (M)-PBXPG films showed a trend similar to the pure PEBAX film. However, the high (H)-PBXPG film with relatively high molecular weight exhibited a distinct permeation jump in the phase change region of H-PEG, which is related to the temperature dependent changes in the morphology structure such as crystallinity and the chemical affinity between the polymer film and gas molecule. Based on these results, it can be expected that H-PBXPG composite films can be used as self-ventilating materials in microwave cooking. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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14 pages, 3708 KiB  
Article
Poly(butylene 2,5-thiophenedicarboxylate): An Added Value to the Class of High Gas Barrier Biopolyesters
by Giulia Guidotti, Matteo Gigli, Michelina Soccio, Nadia Lotti, Massimo Gazzano, Valentina Siracusa and Andrea Munari
Polymers 2018, 10(2), 167; https://doi.org/10.3390/polym10020167 - 9 Feb 2018
Cited by 39 | Viewed by 4290
Abstract
Many efforts are currently devoted to the design and development of high performance bioplastics to replace traditional fossil-based polymers. In response, this contribution presents a new biobased aromatic polyester, i.e., poly(butylene 2,5-thiophenedicarboxylate) (PBTF). Here, PBTF is characterized from the molecular, thermo-mechanical and structural [...] Read more.
Many efforts are currently devoted to the design and development of high performance bioplastics to replace traditional fossil-based polymers. In response, this contribution presents a new biobased aromatic polyester, i.e., poly(butylene 2,5-thiophenedicarboxylate) (PBTF). Here, PBTF is characterized from the molecular, thermo-mechanical and structural point of view. Gas permeability is evaluated at different temperatures, in the range below and above glass transition, providing a full insight into the performances of this material under different operating conditions, and demonstrating the superior gas barrier behavior of PBTF with respect to other polyesters, such as PEF and PET. The combination of calorimetric and diffractometric studies allows for a deep understanding of the structure of PBTF, revealing the presence of a not-induced 2D-ordered phase (meso-phase), responsible for its outstanding gas permeability behavior. The simple synthetic strategy adopted, the exceptional barrier properties, combined with the interesting mechanical characteristics of PBTF open up new scenarios in the world of green and sustainable packaging materials. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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13 pages, 3426 KiB  
Article
A Natural Antibacterial-Antioxidant Film from Soy Protein Isolate Incorporated with Cortex Phellodendron Extract
by Shumin Liang and Lijuan Wang
Polymers 2018, 10(1), 71; https://doi.org/10.3390/polym10010071 - 13 Jan 2018
Cited by 55 | Viewed by 5578
Abstract
An active film was prepared by incorporating cortex Phellodendron extract (CPE, an active agent) into a soybean protein isolate (SPI). Different concentrations of CPE (0%, 10%, 12.5%, 15%, 17.5%, 20%, or 22.5%, w/w, based on SPI) were mixed into the [...] Read more.
An active film was prepared by incorporating cortex Phellodendron extract (CPE, an active agent) into a soybean protein isolate (SPI). Different concentrations of CPE (0%, 10%, 12.5%, 15%, 17.5%, 20%, or 22.5%, w/w, based on SPI) were mixed into the films characterized by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, thermogravimetry, tensile tests, and barrier properties. The rheological properties of the solutions were also tested. The effects of the CPE content on the antibacterial and antioxidant activities of the films were examined. The results indicated that new hydrogen bonds formed between molecules in the films, and the crystallinity of the films decreased. The incorporation of CPE had no significant influence on the thermal stability of the films. Films containing 15% CPE had the maximum tensile strength of 6.00 MPa. The barrier properties against water vapor, oxygen, and light enhanced with the incorporation of CPE. The antioxidant activity of the SPI film was also improved. The films were effective against Staphylococcus aureus (S. aureus, Gram-positive bacteria). These results suggest that the SPI/CPE film can potentially extend the shelf lives of foods. Full article
(This article belongs to the Special Issue Polymers for Packaging Applications)
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