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Bouyahya C, Klonos PA, Zamboulis A, Xanthopoulou E, Ainali NM, Majdoub M, Kyritsis A, Bikiaris DN. Preparation and Structural-Thermodynamical Investigation of Renewable Copolyesters Based on Poly (Ethylene Succinate) and Polyisosorbide. Polymers (Basel) 2024; 16:2173. [PMID: 39125197 PMCID: PMC11314190 DOI: 10.3390/polym16152173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 07/23/2024] [Accepted: 07/27/2024] [Indexed: 08/12/2024] Open
Abstract
A series of novel renewable copolymers based on poly(ethylene succinate) (PESu) and poly(isosorbide succinate) (PISSu), with the Isosorbide (Is)/PESu molar ratio varying from 5/95 to 75/25, were synthesized in-situ and studied in this work. A sum of characterization techniques was employed here for the structural and thermo-dynamical characterization. The sophisticated technique of dielectric spectroscopy, along with proper analysis, enabled the molecular dynamics mapping of both the local and segmental types, which is presented for such materials for the first time. With increasing the Is fraction, shorter copolymeric entities were gradually formed. Based on the overall findings, the systems were found to be homogeneous, e.g., exhibiting single glass transitions, with the two polymer segments being found to be excellently distributed. The latter is indirect, although strong, evidence for the successful copolymerization. The thermal degradation mechanism for the copolymers was exhaustingly explored employing analytical pyrolysis. The systems exhibited, in general, good thermal stability, according to the thermogravimetric analysis. Confirming one of the initial scopes for the present systems, isosorbide plays here the role of hardener (PISSu) over the soft polymer (PESu), and this is reflected in the monotonic increase of the glass transition temperature, Tg, from -16 to ~56 °C. The introduction of Is results in an increase in constraints (hardening of the matrix), while there seems to be an overall densification of the polymer (decrease of the free volume).
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Affiliation(s)
- Chaima Bouyahya
- Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (C.B.); (A.Z.); (N.M.A.)
- Laboratoire des Interfaces et Matériaux Avancés, Université de Monastir, Monastir 5000, Tunisia;
| | - Panagiotis A. Klonos
- Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (C.B.); (A.Z.); (N.M.A.)
- Department of Physics, National Technical University of Athens, Zografou Campus, 157 80 Athens, Greece;
| | - Alexandra Zamboulis
- Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (C.B.); (A.Z.); (N.M.A.)
| | - Eleftheria Xanthopoulou
- Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (C.B.); (A.Z.); (N.M.A.)
| | - Nina Maria Ainali
- Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (C.B.); (A.Z.); (N.M.A.)
| | - Mustapha Majdoub
- Laboratoire des Interfaces et Matériaux Avancés, Université de Monastir, Monastir 5000, Tunisia;
| | - Apostolos Kyritsis
- Department of Physics, National Technical University of Athens, Zografou Campus, 157 80 Athens, Greece;
| | - Dimitrios N. Bikiaris
- Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 541 24 Thessaloniki, Greece; (C.B.); (A.Z.); (N.M.A.)
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Mastalygina EE, Aleksanyan KV. Recent Approaches to the Plasticization of Poly(lactic Acid) (PLA) (A Review). Polymers (Basel) 2023; 16:87. [PMID: 38201752 PMCID: PMC10781029 DOI: 10.3390/polym16010087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2023] [Revised: 12/20/2023] [Accepted: 12/21/2023] [Indexed: 01/12/2024] Open
Abstract
Poly(lactic acid) (PLA) is a polyester attracting growing interest every year in different application fields, such as packaging, cosmetics, food, medicine, etc. Despite its significant advantages, it has low elasticity that may hinder further development and a corresponding rise in volume of consumption. This review opens a discussion of basic approaches to PLA plasticization. These considerations include copolymerization and blending with flexible polymers, introducing oligomers and low-molecular additives, as well as structural modification. It was demonstrated that each approach has its advantages, such as simplicity and low cost, but with disadvantages, including complex processing and the need for additional reagents. According to the analysis of different approaches, it was concluded that the optimal option is the application of copolymers as the additives obtained via reactive mixing to PLA and its blends with other polymers.
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Affiliation(s)
- Elena E. Mastalygina
- Scientific Laboratory “Advanced Composite Materials and Technologies”, Plekhanov Russian University of Economics, 36 Stremyanny Ln., Moscow 117997, Russia
- Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygin St., Moscow 119991, Russia
| | - Kristine V. Aleksanyan
- Engineering Center, Plekhanov Russian University of Economics, 36 Stremyanny Ln., Moscow 117997, Russia
- Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 4 Kosygin St, Moscow 119991, Russia
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3
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Klonos PA, Bikiaris ND, Zamboulis A, Valera MÁ, Mangas A, Kyritsis A, Terzopoulou Z. Segmental mobility in sustainable copolymers based on poly(lactic acid) blocks built onto poly(butylene succinate) in situ. SOFT MATTER 2023; 19:7846-7858. [PMID: 37811662 DOI: 10.1039/d3sm00980g] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Two series of newly synthesized sustainable block copolymers based on poly(butylene succinate) (PBSu) and polylactide (PLA) were studied. The copolymers were synthesized by a ring-opening polymerization of PLA in the presence of two initial PBSu of low molar mass. We focused on the effects of the PBSu/PLA ratio (1/99 up to 15/85), chain length and initial PBSu length on the final thermal transitions in the copolymers with an emphasis on molecular mobility/dynamics and subsequently on crystallization. Both aspects are considered relevant to the final materials performance, as well as facilitation of polymer renewability. Calorimetry and dielectric spectroscopy were the main investigation tools. In the amorphous state (i.e., in which the direct effects of copolymer structure are assessable), the segmental mobility of neat PLA was significantly faster in the copolymers. Segmental mobility was monitored via the decrease in the calorimetric and dielectric (α relaxation) glass-transition temperatures, Tg and Tg,diel, respectively. The effect was systematic with an increase in the PBSu/PLA ratio, and was rationalized through the plasticizing role of PBSu (low-Tg component) and facilitated also by the simultaneous lowering of the chain length in the copolymers. Dielectric spectroscopy allowed evaluation of the dynamical fragility (cooperativity) of chains, which was strongly suppressed in the copolymers. This finding suggested an increase in free volume or a gradual increase of interchain distances. This phenomenon could favor the natural enzymatic degradation of the systems (compostability), which is limited in neat PLA. We recorded enhancement of nucleation and the crystalline fraction in the copolymers that was likely connected with faster chain diffusion. Further lowering of the Tg with the implementation of crystallization was noted (which seemed a controversial effect) but which indicated crystallization-induced phase separation.
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Affiliation(s)
- Panagiotis A Klonos
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
- Department of Physics, National Technical University of Athens, Zografou Campus, 15780, Athens, Greece
| | - Nikolaos D Bikiaris
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
| | - Alexandra Zamboulis
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
| | - Miguel Ángel Valera
- AIMPLAS, Asociación de Investigación de Materiales Plásticos Y Conexas, Carrer de Gustave Eiffel, 4, 46980 Paterna, Valencia, Spain
| | - Ana Mangas
- AIMPLAS, Asociación de Investigación de Materiales Plásticos Y Conexas, Carrer de Gustave Eiffel, 4, 46980 Paterna, Valencia, Spain
| | - Apostolos Kyritsis
- Department of Physics, National Technical University of Athens, Zografou Campus, 15780, Athens, Greece
| | - Zoi Terzopoulou
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
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4
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Siracusa C, Quartinello F, Soccio M, Manfroni M, Lotti N, Dorigato A, Guebitz GM, Pellis A. On the Selective Enzymatic Recycling of Poly(pentamethylene 2,5-furanoate)/Poly(lactic acid) Blends and Multiblock Copolymers. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2023; 11:9751-9760. [PMID: 37425282 PMCID: PMC10324456 DOI: 10.1021/acssuschemeng.3c01796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 06/07/2023] [Indexed: 07/11/2023]
Abstract
Among novel renewable furanoate-based polyesters, poly(pentamethylene 2,5-furandicarboxylate) (PPeF) shows outstanding gas barrier properties and high flexibility. PPeF blending/copolymerization with another well-known bio-based polymer, poly(lactic acid) (PLA), leads to considerably better mechanical and gas barrier properties of the latter, making it suitable for flexible food packaging applications. In this work, enzymatic depolymerization of PLA/PPeF blends with different compositions (1, 3, 5, 20, 30, and 50 wt % PPeF) and a PLA-PPeF block copolymer (50 wt % PPeF) by cutinase 1 from Thermobifida cellulositilytica (Thc_Cut1) was investigated as a possible recycling strategy. Based on quantification of weight loss and high-performance liquid chromatography (HPLC) analysis of released molecules, faster hydrolysis was seen for PLA/PPeF blends with increasing PPeF content when compared to neat PLA, while the block copolymer (P(LA50PeF50)) was significantly less susceptible to hydrolysis. Surface morphology analysis (via scanning electron microscopy), Fourier transform infrared spectroscopy, and NMR analysis confirmed preferential hydrolysis of the PPeF component. Through crystallization, 2,5-furandicarboxylic acid was selectively recovered from the depolymerized films and used for the resynthesis of the PPeF homopolymer, demonstrating the potential of enzymes for novel recycling concepts. The possibility of selective recovery of 2,5-furandicarboxylic acid from the completely depolymerized films with a 75% yield could bring further evidence of the high value of these materials, both in the form of blends and copolymers, for a sustainable whole packaging life cycle, where PPeF is potentially enzymatically recycled and PLA is mechanically recycled.
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Affiliation(s)
- Chiara Siracusa
- acib
GmbH, Konrad-Lorenz-Strasse 20, 3430 Tulln, Donau, Austria
| | - Felice Quartinello
- acib
GmbH, Konrad-Lorenz-Strasse 20, 3430 Tulln, Donau, Austria
- Institute
of Environmental Biotechnology, University
of Natural Resources and Life Sciences Vienna Konrad-Lorenz-Strasse
20, 3430 Tulln, Donau, Austria
| | - Michelina Soccio
- Department
of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Bologna 40138, Italy
- Interdepartmental
Center for Industrial Research on Advanced Applications in Mechanical
Engineering and Materials Technology, CIRI-MAM, University of Bologna, Bologna 40138, Italy
| | - Mattia Manfroni
- Department
of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Bologna 40138, Italy
| | - Nadia Lotti
- Department
of Civil, Chemical, Environmental and Materials Engineering (DICAM), University of Bologna, Bologna 40138, Italy
- Interdepartmental
Center for Industrial Research on Advanced Applications in Mechanical
Engineering and Materials Technology, CIRI-MAM, University of Bologna, Bologna 40138, Italy
- Interdepartmental
Center for Agro-Food Research, CIRI-AGRO, University of Bologna, Bologna 40126, Italy
| | - Andrea Dorigato
- Department
of Industrial Engineering and INSTM Research Unit, University of Trento, Trento 38123, Italy
| | - Georg M. Guebitz
- acib
GmbH, Konrad-Lorenz-Strasse 20, 3430 Tulln, Donau, Austria
- Institute
of Environmental Biotechnology, University
of Natural Resources and Life Sciences Vienna Konrad-Lorenz-Strasse
20, 3430 Tulln, Donau, Austria
| | - Alessandro Pellis
- acib
GmbH, Konrad-Lorenz-Strasse 20, 3430 Tulln, Donau, Austria
- Institute
of Environmental Biotechnology, University
of Natural Resources and Life Sciences Vienna Konrad-Lorenz-Strasse
20, 3430 Tulln, Donau, Austria
- Department
of Chemistry and Industrial Chemistry, Università
degli Studi di Genova, Via Dodecaneso 31, 16146 Genova, Italy
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Makri SP, Xanthopoulou E, Valera MA, Mangas A, Marra G, Ruiz V, Koltsakidis S, Tzetzis D, Zoikis Karathanasis A, Deligkiozi I, Nikolaidis N, Bikiaris D, Terzopoulou Z. Poly(Lactic Acid) Composites with Lignin and Nanolignin Synthesized by In Situ Reactive Processing. Polymers (Basel) 2023; 15:polym15102386. [PMID: 37242959 DOI: 10.3390/polym15102386] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 05/16/2023] [Accepted: 05/18/2023] [Indexed: 05/28/2023] Open
Abstract
Poly(lactic acid) (PLA) composites with 0.5 wt% lignin or nanolignin were prepared with two different techniques: (a) conventional melt-mixing and (b) in situ Ring Opening Polymerization (ROP) by reactive processing. The ROP process was monitored by measuring the torque. The composites were synthesized rapidly using reactive processing that took under 20 min. When the catalyst amount was doubled, the reaction time was reduced to under 15 min. The dispersion, thermal transitions, mechanical properties, antioxidant activity, and optical properties of the resulting PLA-based composites were evaluated with SEM, DSC, nanoindentation, DPPH assay, and DRS spectroscopy. All reactive processing-prepared composites were characterized by means of SEM, GPC, and NMR to assess their morphology, molecular weight, and free lactide content. The benefits of the size reduction of lignin and the use of in situ ROP by reactive processing were demonstrated, as the reactive processing-produced nanolignin-containing composites had superior crystallization, mechanical, and antioxidant properties. These improvements were attributed to the participation of nanolignin in the ROP of lactide as a macroinitiator, resulting in PLA-grafted nanolignin particles that improved its dispersion.
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Affiliation(s)
- Sofia P Makri
- Creative Nano PC, 43 Tatoiou, Metamorfosi, 14451 Athens, Greece
- Laboratory of Polymer and Colors Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Eleftheria Xanthopoulou
- Laboratory of Polymer and Colors Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Miguel Angel Valera
- AIMPLAS, Asociación de Investigación de Materiales Plásticos Y Conexas, Carrer de Gustave Eiffel, 4, 46980 Valencia, Spain
| | - Ana Mangas
- AIMPLAS, Asociación de Investigación de Materiales Plásticos Y Conexas, Carrer de Gustave Eiffel, 4, 46980 Valencia, Spain
| | - Giacomo Marra
- AIMPLAS, Asociación de Investigación de Materiales Plásticos Y Conexas, Carrer de Gustave Eiffel, 4, 46980 Valencia, Spain
| | - Víctor Ruiz
- AIMPLAS, Asociación de Investigación de Materiales Plásticos Y Conexas, Carrer de Gustave Eiffel, 4, 46980 Valencia, Spain
| | - Savvas Koltsakidis
- Digital Manufacturing and Materials Characterization Laboratory, School of Science and Technology, International Hellenic University, 14 km Thessaloniki, 57001 N. Moudania, Greece
| | - Dimitrios Tzetzis
- Digital Manufacturing and Materials Characterization Laboratory, School of Science and Technology, International Hellenic University, 14 km Thessaloniki, 57001 N. Moudania, Greece
| | | | | | - Nikolaos Nikolaidis
- Laboratory of Polymer and Colors Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Dimitrios Bikiaris
- Laboratory of Polymer and Colors Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
| | - Zoi Terzopoulou
- Laboratory of Polymer and Colors Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece
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Bouyahya C, Bikiaris ND, Zamboulis A, Kyritsis A, Majdoub M, Klonos PA. Crystallization and molecular mobility in renewable semicrystalline copolymers based on polycaprolactone and polyisosorbide. SOFT MATTER 2022; 18:9216-9230. [PMID: 36426754 DOI: 10.1039/d2sm01198k] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
A series of novel block copolymers based on two biodegradable polymers, poly(ε-caprolactone), PCL, and poly(isosorbide), PIS, with PIS fractions 5, 10, and 25 wt%, are studied herein. The aim is to assess the effects of the amorphous PIS phase on the properties of the semicrystalline PCL (majority), in addition to the synthesis strategy. The latter involved the polymerization of caprolactone onto initial PIS of low molar mass, resulting, thus, in gradually shorter PCL blocks when the starting amount of PIS is increased. The structure-property relationship investigation, with an emphasis on molecular mobility and crystallization, involves the following sum of complementary techniques: differential scanning calorimetry, dielectric spectroscopy, polarized optical microscopy and X-ray diffraction. The molecular mobility map for these PCL/PIS and initial PIS is drawn here for the first time. Despite the high glass transition temperature of PIS (Tg ∼ 51 °C) compared to that of PCL (-66 °C), the Tg of the copolymers barely changes, as it is mainly ruled by crystallinity. The latter seems to be facilitated in the copolymers, in both the amount and the rate. The local molecular mobility of PCL and PCL/PIS consists of faster γPCL relaxation which is unaffected in the copolymers, whereas the slower βPCL process arising from the backbone ester group rotation exhibits a systematic deceleration in the presence of PIS. A connection between such local motions and the corresponding segmental α relaxation, observed previously in other polyesters, is also found to be true here. Apart from that, the dielectric Tg as well as the cooperativity of the polymer chains drop moderately, which indicates spatial confinement between the PCL crystals, whereas correlations with the looser lamellar chain packing within the spherulites are gained. The relaxations of initial PIS, i.e., γPIS, βPIS and αPIS, could not be resolved within the copolymers. Along with other properties, such as ionic conductivity, we conclude to the homogeneity of our systems, with sufficient PCL/PIS distribution.
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Affiliation(s)
- Chaima Bouyahya
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
- Laboratoire des Interfaces et Matériaux Avancés, Université de Monastir, 5000 Monastir, Tunisia.
| | - Nikolaos D Bikiaris
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
| | - Alexandra Zamboulis
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
| | - Apostolos Kyritsis
- Department of Physics, National Technical University of Athens, Zografou Campus, 15780, Athens, Greece
| | - Mustapha Majdoub
- Laboratoire des Interfaces et Matériaux Avancés, Université de Monastir, 5000 Monastir, Tunisia.
| | - Panagiotis A Klonos
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
- Department of Physics, National Technical University of Athens, Zografou Campus, 15780, Athens, Greece
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7
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Recent advances on reactive Extrusion of Poly(lactic acid). Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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8
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Revisiting Non-Conventional Crystallinity-Induced Effects on Molecular Mobility in Sustainable Diblock Copolymers of Poly(propylene adipate) and Polylactide. Molecules 2022; 27:molecules27217449. [PMID: 36364274 PMCID: PMC9655265 DOI: 10.3390/molecules27217449] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2022] [Revised: 10/24/2022] [Accepted: 10/26/2022] [Indexed: 11/06/2022] Open
Abstract
This work deals with molecular mobility in renewable block copolymers based on polylactide (PLA) and poly(propylene adipate) (PPAd). In particular, we assess non-trivial effects on the mobility arising from the implementation of crystallization. Differential scanning calorimetry, polarized light microscopy and broadband dielectric spectroscopy were employed in combination for this study. The materials were subjected to various thermal treatments aiming at the manipulation of crystallization, namely, fast and slow cooling, isothermal melt- and cold-crystallization. Subsequently, we evaluated the changes recorded in the overall thermal behavior, semicrystalline morphology and molecular mobility (segmental and local). The molecular dynamics map for neat PPAd is presented here for the first time. Unexpectedly, the glass transition temperature, Tg, in the amorphous state drops upon crystallization by 8–50 K. The drop becomes stronger with the increase in the PPAd fraction. Compared to the amorphous state, crystallization leads to significantly faster segmental dynamics with severely suppressed cooperativity. For the PLA/PPAd copolymers, the effects are systematically stronger in the cold- as compared to the melt-crystallization, whereas the opposite happens for neat PLA. The local βPLA relaxation of PLA was, interestingly, recorded to almost vanish upon crystallization. This suggests that the corresponding molecular groups (carbonyl) are strongly involved and immobilized within the semicrystalline regions. The overall results suggest the involvement of either spatial nanoconfinement imposed on the mobile chains within the inter-crystal amorphous areas and/or a crystallization-driven effect of nanophase separation. The latter phase separation seems to be at the origins of the significant discrepancy recorded between the calorimetric and dielectric recordings on Tg in the copolymers. Once again, compared to more conventional techniques such as calorimetry, dielectric spectroscopy was proved a powerful and quite sensitive tool in recording such effects as well as in providing indirect indications for the polymer chains’ topology.
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Klonos PA, Lazaridou M, Samiotaki C, Kyritsis A, Bikiaris DN. Dielectric and calorimetric study in renewable polymer blends based on poly(ethylene adipate) and poly(lactic acid) with microphase separation. POLYMER 2022. [DOI: 10.1016/j.polymer.2022.125329] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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10
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Klonos PA, Terzopoulou Z, Zamboulis A, Valera MÁ, Mangas A, Kyritsis A, Pissis P, Bikiaris DN. Direct and indirect effects on molecular mobility in renewable polylactide-poly(propylene adipate) block copolymers as studied via dielectric spectroscopy and calorimetry. SOFT MATTER 2022; 18:3725-3737. [PMID: 35503564 DOI: 10.1039/d2sm00261b] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
In this work, we study a series of sustainable block copolymers based on polylactide, PLA, and poly(propylene adipate), PPAd, both polymers being prepared from renewable resources. Envisaging a wide range of future applications in the frame of a green and circular economy, e.g., packaging materials replacing conventional petrochemicals, the employment of PPAd aims at lowering the glass transition and melting temperatures of PLA and, finally, facilitation of the enzymatic degradation and compostability. The copolymers have been synthesized via ring opening polymerization of lactides in the presence of propylene adipate oligomers (5, 15 and 25%). The direct effects on the molecular mobility by the structure/composition are assessed in the amorphous state employing broadband dielectric spectroscopy (BDS) and calorimetry. BDS allowed the recording of local PLA and PPAd dynamics in all cases. The effects on local relaxations suggest favoring of interchain interactions, both PLA-PPAd and PPAd-PPAd. Regarding the more important segmental dynamics, the presence of PPAd leads to faster polymer chain diffusion, as monitored by the significant lowering of the dielectric and calorimetric glass transition temperature, Tg. This suggests the plasticizing role of PPAd on PLA (majority) in combination with the lowering of the average molar mass, Mn, in the copolymers from ∼75 to ∼30 kg mol-1, which is the actual scope for the synthesis of these materials. Interestingly, a strong suppression in fragility (chain cooperativity) is additionally recorded. In contrast to calorimetry and due to the high resolving power of BDS, for the higher PPAd fraction, the weak segmental relaxation of PPAd was additionally recorded. Overall, the recordings suggest a strong increase in free volume and two individual dynamic states, one for 0 and 5% PPAd and another for 15 and 25% PPAd. Within the latter, we gained indications for partial phase nano-separation of PPAd. Regarding indirect effects, these were followed via crystallization. Independent of the method of crystallization, namely, melt or cold, the presence of PPAd led to the systematic lowering of crystallization and melting temperatures and enthalpies. The effects reflect the decrease of crystalline nuclei, which is confirmed by optical microscopy as in the copolymers fewer although larger crystals are formed.
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Affiliation(s)
- Panagiotis A Klonos
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
- Department of Physics, National Technical University of Athens (NTUA), Zografou Campus, 15780, Athens, Greece
| | - Zoi Terzopoulou
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
| | - Alexandra Zamboulis
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
| | - Miguel Ángel Valera
- AIMPLAS, Asociación de Investigación de Materiales Plásticos Y Conexas, Carrer de Gustave Eiffel, 4, 46980 Valencia, Spain
| | - Ana Mangas
- AIMPLAS, Asociación de Investigación de Materiales Plásticos Y Conexas, Carrer de Gustave Eiffel, 4, 46980 Valencia, Spain
| | - Apostolos Kyritsis
- Department of Physics, National Technical University of Athens (NTUA), Zografou Campus, 15780, Athens, Greece
| | - Polycarpos Pissis
- Department of Physics, National Technical University of Athens (NTUA), Zografou Campus, 15780, Athens, Greece
| | - Dimitrios N Bikiaris
- Department of Chemistry, Laboratory of Polymer Chemistry and Technology, Aristotle University of Thessaloniki, GR-541 24, Thessaloniki, Greece.
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11
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Qian L, Zhang K, Guo X, Zhou J, Yu M. Single-Chain Mechanical Properties of Gelatin: A Single-Molecule Study. Polymers (Basel) 2022; 14:polym14050869. [PMID: 35267692 PMCID: PMC8912665 DOI: 10.3390/polym14050869] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Revised: 02/18/2022] [Accepted: 02/21/2022] [Indexed: 01/27/2023] Open
Abstract
Gelatin is an important natural biological resource with a wide range of applications in the pharmaceutical, industrial and food industries. We investigated the single-chain behaviors of gelatin by atomic force microscopy (AFM)-based single-molecule force spectroscopy (SMFS), and found that gelatin exists as long chains by fitting with the M-FJC model. By comparing the single-chain elasticity in a nonpolar organic solvent (nonane) and DI water, it was surprising to find that there was almost no difference in the single-chain elasticity of gelatin in nonane and DI water. Considering the specificity of gelatin solubility and the solvent size effect of nonane molecules, when a single gelatin chain is pulled into loose nonane, dehydration does not occur due to strong binding water interactions. Gelatin chains can only interact with water molecules at high temperatures; therefore, no further interaction of single gelatin chains with water molecules occurred at the experimental temperature. This eventually led to almost no difference in the single-chain F-E curves under the two conditions. It is expected that our study will enable the deep exploration of the interaction between water molecules and gelatin and provide a theoretical basis and experimental foundation for the design of gelatin-based materials with more functionalities.
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Affiliation(s)
- Lu Qian
- School of Materials Science and Engineering, South China University of Technology, Guangzhou 510000, China;
| | - Kai Zhang
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China; (K.Z.); (X.G.); (J.Z.)
| | - Xin Guo
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China; (K.Z.); (X.G.); (J.Z.)
| | - Junyu Zhou
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China; (K.Z.); (X.G.); (J.Z.)
| | - Miao Yu
- School of Mechanical Engineering, Sichuan University, Chengdu 610065, China; (K.Z.); (X.G.); (J.Z.)
- Correspondence: ; Tel.: +86-28-85405307
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