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Bernardes GP, Andrade MP, Poletto M, Luiz NR, Santana RMC, Forte MMDC. Evaluation of Thermal Decomposition Kinetics of Poly (Lactic Acid)/Ethylene Elastomer (EE) Blends. Polymers (Basel) 2023; 15:4324. [PMID: 37960004 PMCID: PMC10648464 DOI: 10.3390/polym15214324] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 10/26/2023] [Accepted: 11/02/2023] [Indexed: 11/15/2023] Open
Abstract
The influences of ethylene-based elastomer (EE) and the compatibilizer agent ethylene-butyl acrylate-glycidyl methacrylate (EBAGMA) on the thermal degradation of PLA/EE blends were evaluated by the thermal degradation kinetics and thermodynamic parameters using thermogravimetry. The presence of EE and EBAGMA synergistically improved the PLA thermal stability. The temperature of 10% of mass loss (T10%) of PLA was around 365 °C, while in the compatibilized PLA/EE blend, this property increased to 370 °C. The PLA average activation energy (Ea¯) reduced in the PLA/EE blend (from 96 kJ/mol to 78 kJ/mol), while the presence of EBAGMA in the PLA/EE blend increased the Ea¯ due to a better blend compatibilization. The solid-state thermal degradation of the PLA and PLA/EE blends was classified as a D-type degradation mechanism. In general, the addition of EE increased the thermodynamic parameters when compared to PLA and the compatibilized blend due to the increase in the collision rate between the components over the thermal decomposition.
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Affiliation(s)
- Giordano P. Bernardes
- Department of Mechatronic Engineering, Atlantic Technological University (ATU) Sligo, Ash Lane, F91 YW50 Sligo, Ireland
| | - Matheus P. Andrade
- Postgraduate Program in Engineering of Processes and Technologies (PGEPROTEC), University of Caxias Do Sul (UCS), Caxias Do Sul 95070-560, Brazil;
| | - Matheus Poletto
- Postgraduate Program in Engineering of Processes and Technologies (PGEPROTEC), University of Caxias Do Sul (UCS), Caxias Do Sul 95070-560, Brazil;
| | - Nathália R. Luiz
- Laboratory of Polymeric Materials (LAPOL), School of Engineering, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil; (N.R.L.); (R.M.C.S.); (M.M.d.C.F.)
| | - Ruth M. C. Santana
- Laboratory of Polymeric Materials (LAPOL), School of Engineering, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil; (N.R.L.); (R.M.C.S.); (M.M.d.C.F.)
| | - Maria M. de C. Forte
- Laboratory of Polymeric Materials (LAPOL), School of Engineering, Federal University of Rio Grande do Sul (UFRGS), Porto Alegre 90010-150, Brazil; (N.R.L.); (R.M.C.S.); (M.M.d.C.F.)
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Yadav SK, Kumar A, Mehta N. Synthesis and characterization of nanostructured graphene-doped selenium. RSC Adv 2023; 13:13564-13574. [PMID: 37152579 PMCID: PMC10155193 DOI: 10.1039/d3ra01199b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Accepted: 04/18/2023] [Indexed: 05/09/2023] Open
Abstract
In this work, we explore various properties of elemental selenium glass (g-Se) by doping with graphene through the facile melt-quench technique. The structural information of the synthesized sample was found by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and Raman spectroscopy. The analyses confirm that the graphene-doped g-Se behaves like a glass-ceramic material. Electrical and dielectric measurements were performed to discover the consequences of graphene incorporation on the nano-structure of g-Se. The electrical measurements of the dielectric parameters (i.e., dielectric constant ε' and loss ε'') and conductivity (σ ac) reveal that graphene incorporation causes a rise in the dielectric constant but simultaneously increases dielectric loss. The enhancement in ε' and ε'' values is thought to be a consequence of the interface effect between graphene and the host selenium glass. Calorimetric experiments were performed in a standard differential scanning calorimetry (DSC) unit on the glassy nanocomposite in non-isothermal mode. By measuring the kinetic temperatures at four heating rates, the kinetics of the crystallization/glass transition were studied. The results were examined to understand the role of graphene doping on the well-known phase transitions (i.e., glass transition and crystallization) of g-Se.
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Affiliation(s)
| | - Amit Kumar
- Department of Physics, Banaras Hindu University Varanasi 221005 India
- Sunbeam College for Women Bhagwanpur Varanasi 221005 India
| | - N Mehta
- Department of Physics, Banaras Hindu University Varanasi 221005 India
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du Toit LC, Hulisani Demana P, Essop Choonara Y. A nano-enabled biotinylated anti-LDL theranostic system to modulate systemic LDL cholesterol. Int J Pharm 2022; 628:122258. [DOI: 10.1016/j.ijpharm.2022.122258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 09/15/2022] [Accepted: 09/28/2022] [Indexed: 10/31/2022]
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4
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Wang Q, Li Y, Zhang B, Ding X, Zheng A. Shape memory performances of homogeneous poly(L-lactide-co-ε-caprolactone)/polytrimethylene carbonate-grafted functionalized graphene oxide nanocomposites. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2022.111291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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Fabrication of PLA/PCL/Graphene Nanoplatelet (GNP) Electrically Conductive Circuit Using the Fused Filament Fabrication (FFF) 3D Printing Technique. MATERIALS 2022; 15:ma15030762. [PMID: 35160709 PMCID: PMC8836401 DOI: 10.3390/ma15030762] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 01/07/2022] [Accepted: 01/17/2022] [Indexed: 02/01/2023]
Abstract
For the purpose of fabricating electrically conductive composites via the fused filament fabrication (FFF) technique whose properties were compared with injection-moulded properties, poly(lactic acid) (PLA) and polycaprolactone (PCL) were mixed with different contents of graphene nanoplatelets (GNP). The wettability, morphological, rheological, thermal, mechanical, and electrical properties of the 3D-printed samples were investigated. The microstructural images showed the selective localization of the GNPs in the PCL nodules that are dispersed in the PLA phase. The electrical resistivity results using the four-probes method revealed that the injection-moulded samples are insulators, whereas the 3D-printed samples featuring the same graphene content are semiconductors. Varying the printing raster angles also exerted an influence on the electrical conductivity results. The electrical percolation threshold was found to be lower than 15 wt.%, whereas the rheological percolation threshold was found to be lower than 10 wt.%. Furthermore, the 20 wt.% and 25 wt.% GNP composites were able to connect an electrical circuit. An increase in the Young’s modulus was shown with the percentage of graphene. As a result, this work exhibited the potential of the FFF technique to fabricate biodegradable electrically conductive PLA-PCL-GNP composites that can be applicable in the electronic domain.
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Powder injection molded nano copper oxide grafted graphene reinforced copper matrix composites. POWDER TECHNOL 2022. [DOI: 10.1016/j.powtec.2021.117101] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Hasheminejad K, Montazeri A, Hasheminejad H. Tailoring adhesion characteristics of poly(L-lactic acid)/graphene nanocomposites by end-grafted polymer chains: An atomic-level study. Eur Polym J 2021. [DOI: 10.1016/j.eurpolymj.2021.110351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Manafi P, Nazockdast H, Karimi M, Sadighi M, Magagnin L. Microstructural Development and Rheological Study of a Nanocomposite Gel Polymer Electrolyte Based on Functionalized Graphene for Dye-Sensitized Solar Cells. Polymers (Basel) 2020; 12:polym12071443. [PMID: 32605131 PMCID: PMC7408189 DOI: 10.3390/polym12071443] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 06/21/2020] [Accepted: 06/25/2020] [Indexed: 12/04/2022] Open
Abstract
For a liquid electrolyte-based dye-sensitized solar cell (DSSC), long-term device instability is known to negatively affect the ionic conductivity and cell performance. These issues can be resolved by using the so called quasi-solid-state electrolytes. Despite the enhanced ionic conductivity of graphene nanoplatelets (GNPs), their inherent tendency toward aggregation has limited their application in quasi-solid-state electrolytes. In the present study, the GNPs were chemically modified by polyethylene glycol (PEG) through amidation reaction to obtain a dispersible nanostructure in a poly(vinylidene fluoride-co-hexafluoro propylene) copolymer and polyethylene oxide (PVDF–HFP/PEO) polymer-blended gel electrolyte. Maximum ionic conductivity (4.11 × 10−3 S cm−1) was obtained with the optimal nanocomposite gel polymer electrolyte (GPE) containing 0.75 wt% functionalized graphene nanoplatelets (FGNPs), corresponding to a power conversion efficiency of 5.45%, which was 1.42% and 0.67% higher than those of the nanoparticle-free and optimized-GPE (containing 1 wt% GNP) DSSCs, respectively. Incorporating an optimum dosage of FGNP, a homogenous particle network was fabricated that could effectively mobilize the redox-active species in the amorphous region of the matrix. Surface morphology assessments were further performed through scanning electron microscopy (SEM). The results of rheological measurements revealed the plasticizing effect of the ionic liquid (IL), offering a proper insight into the polymer–particle interactions within the polymeric nanocomposite. Based on differential scanning calorimetry (DSC) investigations, the decrease in the glass transition temperature (and the resultant increase in flexibility) highlighted the influence of IL and polymer–nanoparticle interactions. The obtained results shed light on the effectiveness of the FGNPs for the DSSCs.
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Affiliation(s)
- Pedram Manafi
- Mahshahr Campus, Amirkabir University of Technology, Mahshahr P.O. Box 63517-13178, Iran;
| | - Hossein Nazockdast
- Department of Polymer Engineering and Color Technology, Amirkabir University of Technology, Tehran P.O. Box 15875-4413, Iran
- Correspondence: (H.N.); (L.M.)
| | - Mohammad Karimi
- School of Materials and Advanced processes Engineering, Department of Textile Engineering, Amirkabir University of Technology (Tehran Polytechnic), Tehran P.O. Box 15875-4413, Iran;
| | - Mojtaba Sadighi
- Department of Mechanical Engineering, Amirkabir University of Technology, Tehran P.O. Box 15875-4413, Iran;
| | - Luca Magagnin
- Department of Chemistry, Materials and Chemical Engineering “Giulio Natta,” Politecnico di Milano, 20131 Milano, Italy
- Correspondence: (H.N.); (L.M.)
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Electrically-Conductive Polyketone Nanocomposites Based on Reduced Graphene Oxide. Polymers (Basel) 2020; 12:polym12040923. [PMID: 32316345 PMCID: PMC7240681 DOI: 10.3390/polym12040923] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 04/11/2020] [Accepted: 04/13/2020] [Indexed: 01/09/2023] Open
Abstract
In this work, we investigated the functionalization of polyketone 30 (PK30) with glycyl-glycine (Gly-Gly) via the Paal-Knorr reaction with the aim of homogenously dispersing two types of reduced graphene oxide (rGO, i.e., lrGO and hrGO, the former characterized by a lower degree of reduction in comparison to the latter) by non-covalent interactions. The functional PK30-Gly-Gly polymer was effective in preparing composites with homogeneously distributed rGO characterized by an effective percolation threshold at 5 wt. %. All the composites showed a typical semiconductive behavior and stable electrical response after several heating/cooling cycles from 30 to 115 °C. Composites made by hrGO displayed the same resistive behaviour even if flanked by a considerable improvement on conductivity, in agreement with the more reduced rGO content. Interestingly, no permanent percolative network was shown by the composite with 4 wt. % of lrGO at temperatures higher than 45 °C. This material can be used as an ON-OFF temperature sensor and could find interesting applications as sensing material in soft robotics applications.
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Generalized kinetics for thermal degradation and melt rheology for poly (lactic acid)/poly (butylene succinate)/functionalized chitosan based reactive nanobiocomposite. Int J Biol Macromol 2019; 141:831-842. [DOI: 10.1016/j.ijbiomac.2019.09.058] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 09/06/2019] [Accepted: 09/07/2019] [Indexed: 02/07/2023]
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Thermal degradation kinetics of flame-retardant glass-fiber-reinforced polyamide 6T composites based on bridged DOPO derivatives. Polym Bull (Berl) 2018. [DOI: 10.1007/s00289-018-2437-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Manafi P, Ghasemi I, Manafi MR, Ehsaninamin P, Hassanpour Asl F. Non-isothermal crystallization kinetics assessment of poly(lactic acid)/graphene nanocomposites. IRANIAN POLYMER JOURNAL 2017. [DOI: 10.1007/s13726-017-0527-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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Tripathi N, Monika, Katiyar V. Poly (lactic acid)/modified gum arabic based bionanocomposite films: Thermal degradation kinetics. POLYM ENG SCI 2017. [DOI: 10.1002/pen.24497] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Neelima Tripathi
- Department of Chemical Engineering; Indian Institute of Technology Guwahati; Guwahati Assam 781039 India
| | - Monika
- Department of Chemical Engineering; Indian Institute of Technology Guwahati; Guwahati Assam 781039 India
| | - Vimal Katiyar
- Department of Chemical Engineering; Indian Institute of Technology Guwahati; Guwahati Assam 781039 India
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Rimez B, Van Assche G, Bourbigot S, Rahier H. Modelled decomposition kinetics of flame retarded poly(vinyl acetate). Polym Degrad Stab 2016. [DOI: 10.1016/j.polymdegradstab.2016.06.021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Mechanical and thermal properties of cationic ring-opening o-cresol formaldehyde epoxy/polyurethane acrylate composites enhanced by reducing graphene oxide. Polym Bull (Berl) 2016. [DOI: 10.1007/s00289-016-1605-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Graphene nanoplatelets dispersion in poly(l-lactic acid): preparation method and its influence on electrical, crystallinity and thermomechanical properties. IRANIAN POLYMER JOURNAL 2016. [DOI: 10.1007/s13726-015-0413-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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