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Kashmari K, Patil SU, Kemppainen J, Shankara G, Odegard GM. Optimal Molecular Dynamics System Size for Increased Precision and Efficiency for Epoxy Materials. J Phys Chem B 2024; 128:4255-4265. [PMID: 38648370 DOI: 10.1021/acs.jpcb.4c00845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Abstract
Molecular dynamics (MD) simulation is an important tool for predicting thermo-mechanical properties of polymer resins at the nanometer length scale, which is particularly important for efficient computationally driven design of advanced composite materials and structures. Because of the statistical nature of modeling amorphous materials on the nanometer length scale, multiple MD models (replicates) are typically built and simulated for statistical sampling of predicted properties. Larger replicates generally provide higher precision in the predictions but result in higher simulation times. Unfortunately, there is insufficient information in the literature to establish guidelines between MD model size and the resulting precision in predicted thermo-mechanical properties. The objective of this study was to determine the optimal MD model size of epoxy resin to balance efficiency and precision. The results show that an MD model size of 15,000 atoms provides for the fastest simulations without sacrificing precision in the prediction of mass density, elastic properties, strength, and thermal properties of epoxy. The results of this study are important for efficient computational process modeling and integrated computational materials engineering (ICME) for the design of next-generation composite materials for demanding applications.
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Affiliation(s)
- Khatereh Kashmari
- Michigan Technological University, Houghton, Michigan 49931, United States
| | - Sagar U Patil
- Michigan Technological University, Houghton, Michigan 49931, United States
| | - Josh Kemppainen
- Michigan Technological University, Houghton, Michigan 49931, United States
| | - Gowtham Shankara
- Michigan Technological University, Houghton, Michigan 49931, United States
| | - Gregory M Odegard
- Michigan Technological University, Houghton, Michigan 49931, United States
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2
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Tang Q, Jiang J, Li J, Zhao L, Xi Z. Effects of Chemical Composition and Cross-Linking Degree on the Thermo-Mechanical Properties of Bio-Based Thermosetting Resins: A Molecular Dynamics Simulation Study. Polymers (Basel) 2024; 16:1229. [PMID: 38732698 PMCID: PMC11085128 DOI: 10.3390/polym16091229] [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: 03/28/2024] [Revised: 04/23/2024] [Accepted: 04/24/2024] [Indexed: 05/13/2024] Open
Abstract
Bio-based epoxy resins have received significant attention in terms of concerns regarding carbon emission. Epoxidized soybean oil (ESO) derived from sustainable feedstock has been widely used to blend with traditional diglycidyl ether of bisphenol-A (DGEBA) to replace some of the petroleum-based components. In this work, molecular dynamics (MD) simulations were applied to track the network formation and predict the performance of methyl hexahydrophthalic anhydride (MHHPA)-cured ESO/DGEBA blend systems. The effects of ESO content and cross-linking degree on the mass density, volumetric shrinkage, glass transition temperature (Tg), coefficient of thermal expansion (CTE), Young's modulus, yield strength, and Poisson's ratio of the epoxy resin were systematically investigated. The results show that systems with high ESO content achieve gelation at low cross-linking degree. The Tg value, Young's modulus, and yield strength increase with the increase in cross-linking degree, but the CTE at the glassy state and Poisson's ratio decrease. The comparison results between the simulated and experimental data demonstrated that the MD simulations can accurately predict the thermal and mechanical properties of ESO-based thermosets. This study gains insight into the variation in thermo-mechanical properties of anhydride-cured ESO/DGEBA-based epoxy resins during the cross-linking process and provides a rational strategy for optimizing bio-based epoxy resins.
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Affiliation(s)
- Qiuyu Tang
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.T.); (J.L.); (L.Z.)
| | - Jie Jiang
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.T.); (J.L.); (L.Z.)
- Shanghai Key Laboratory of Advanced Polymeric Materials, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jinjin Li
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.T.); (J.L.); (L.Z.)
| | - Ling Zhao
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.T.); (J.L.); (L.Z.)
- Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Zhenhao Xi
- State Key Laboratory of Chemical Engineering, School of Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China; (Q.T.); (J.L.); (L.Z.)
- Shanghai Key Laboratory of Multiphase Materials Chemical Engineering, East China University of Science and Technology, Shanghai 200237, China
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3
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Pisani W, Wedgeworth DN, Burroughs JF, Thornell TL, Newman JK, Shukla MK. Micromechanical Dilution of PLA/PETG-Glass/Iron Nanocomposites: A More Efficient Molecular Dynamics Approach. ACS OMEGA 2024; 9:14887-14898. [PMID: 38585113 PMCID: PMC10993258 DOI: 10.1021/acsomega.3c08264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Revised: 02/23/2024] [Accepted: 03/04/2024] [Indexed: 04/09/2024]
Abstract
Polylactic acid (PLA) and poly(ethylene terephthalate glycol) (PETG) are popular thermoplastics used in additive manufacturing applications. The mechanical properties of PLA and PETG can be significantly improved by introducing fillers, such as glass and iron nanoparticles (NPs), into the polymer matrix. Molecular dynamics (MD) simulations with the reactive INTERFACE force field were used to predict the mechanical responses of neat PLA/PETG and PLA-glass/iron and PETG-glass/iron nanocomposites with relatively high loadings of glass/iron NPs. We found that the iron and glass NPs significantly increased the elastic moduli of the PLA matrix, while the PETG matrix exhibited modest increases in elastic moduli. This difference in reinforcement ability may be due to the slightly greater attraction between the glass/iron NP and PLA matrix. The NASA Multiscale Analysis Tool was used to predict the mechanical response across a range of volume percent glass/iron filler by using only the neat and highly loaded MD predictions as input. This provides a faster and more efficient approach than creating multiple MD models per volume percent per polymer/filler combination. To validate the micromechanics predictions, experimental samples incorporating hollow glass microspheres (MS) and carbonyl iron particles (CIP) into PLA/PETG were developed and tested for elastic modulus. The CIP produced a larger reinforcement in elastic modulus than the MS, with similar increases in elastic modulus between PLA/CIP and PETG/CIP at 7.77 vol % CIP. The micromechanics-based mechanical predictions compare excellently with the experimental values, validating the integrated micromechanical/MD simulation-based approach.
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Affiliation(s)
- William
A. Pisani
- Oak
Ridge Institute for Science and Education, Oak Ridge, Tennessee 37831, United States
- Environmental
Laboratory, US Army Engineer Research and
Development Center, Vicksburg, Mississippi 39180, United States
| | - Dane N. Wedgeworth
- Geotechnical
and Structures Laboratory, US Army Engineer
Research and Development Center, Vicksburg, Mississippi 39180, United States
| | - Jedadiah F. Burroughs
- Geotechnical
and Structures Laboratory, US Army Engineer
Research and Development Center, Vicksburg, Mississippi 39180, United States
| | - Travis L. Thornell
- Geotechnical
and Structures Laboratory, US Army Engineer
Research and Development Center, Vicksburg, Mississippi 39180, United States
| | - J. Kent Newman
- Geotechnical
and Structures Laboratory, US Army Engineer
Research and Development Center, Vicksburg, Mississippi 39180, United States
| | - Manoj K. Shukla
- Environmental
Laboratory, US Army Engineer Research and
Development Center, Vicksburg, Mississippi 39180, United States
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4
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Kashmari K, Al Mahmud H, Patil SU, Pisani WA, Deshpande P, Maiaru M, Odegard GM. Multiscale Process Modeling of Semicrystalline PEEK for Tailored Thermomechanical Properties. ACS APPLIED ENGINEERING MATERIALS 2023; 1:3167-3177. [PMID: 38037665 PMCID: PMC10682963 DOI: 10.1021/acsaenm.3c00586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2023] [Revised: 10/18/2023] [Accepted: 10/18/2023] [Indexed: 12/02/2023]
Abstract
Polyether ether ketone (PEEK) is a semicrystalline thermoplastic that is used in high-performance composites for a wide range of applications. Because the crystalline phase has a higher mass density than that of the amorphous phase, the evolution of the crystalline phase during high-temperature annealing processing steps results in the formation of residual stresses and laminate deformations, which can adversely affect the composite laminate performance. Multiscale process modeling, utilizing molecular dynamics, micromechanics, and phenomenological PEEK crystal kinetic laws, is used to predict the evolution of volumetric shrinkage, elastic properties, and thermal properties, as a function of crystalline phase evolution, and thus annealing time, in the 306-328 °C temperature range. The results indicate that lower annealing temperatures in this range result in a faster evolution of thermomechanical properties and shrinkage toward the pure crystalline values. Therefore, from the perspective of composite processing, it may be more advantageous to choose the higher annealing rates in this range to slow the volumetric shrinkage and allow PEEK stress relaxation mechanisms more time to relax internal residual stresses in PEEK composite laminates and structures.
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Affiliation(s)
- Khatereh Kashmari
- Michigan
Technological University, Houghton, Michigan 49931, United States
| | | | - Sagar U. Patil
- Michigan
Technological University, Houghton, Michigan 49931, United States
| | - William A. Pisani
- Michigan
Technological University, Houghton, Michigan 49931, United States
| | | | - Marianna Maiaru
- University
of Massachusetts Lowell, Lowell, Massachusetts 01854, United States
| | - Gregory M. Odegard
- Michigan
Technological University, Houghton, Michigan 49931, United States
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5
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Odegard GM, Patil SU, Gaikwad PS, Deshpande P, Krieg AS, Shah SP, Reyes A, Dickens T, King JA, Maiaru M. Accurate predictions of thermoset resin glass transition temperatures from all-atom molecular dynamics simulation. SOFT MATTER 2022; 18:7550-7558. [PMID: 36149371 DOI: 10.1039/d2sm00851c] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
To enable the design and development of the next generation of high-performance composite materials, there is a need to establish improved computational simulation protocols for accurate and efficient prediction of physical, mechanical, and thermal properties of thermoset resins. This is especially true for the prediction of glass transition temperature (Tg), as there are many discrepancies in the literature regarding simulation protocols and the use of cooling rate correction factors for predicting values using molecular dynamics (MD) simulation. The objectives of this study are to demonstrate accurate prediction the Tg with MD without the use of cooling rate correction factors and to establish the influence of simulated conformational state and heating/cooling cycles on physical, mechanical, and thermal properties predicted with MD. The experimentally-validated MD results indicate that accurate predictions of Tg, elastic modulus, strength, and coefficient of thermal expansion are highly reliant upon establishing MD models with mass densities that match experiment within 2%. The results also indicate the cooling rate correction factors, model building within different conformational states, and the choice of heating/cooling simulation runs do not provide statistically significant differences in the accurate prediction of Tg values, given the typical scatter observed in MD predictions of amorphous polymer properties.
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Affiliation(s)
| | - Sagar U Patil
- Michigan Technological University, Houghton, MI 49931, USA.
| | | | | | - Aaron S Krieg
- Michigan Technological University, Houghton, MI 49931, USA.
| | - Sagar P Shah
- University of Massachusetts Lowell, MA 01854, USA
| | - Aspen Reyes
- Florida A&M University, Tallahassee, FL 32306, USA
| | | | - Julia A King
- Michigan Technological University, Houghton, MI 49931, USA.
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6
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Thermal decomposition behavior and flame retardancy of bioepoxies, their blends and composites: A comprehensive review. Eur Polym J 2022. [DOI: 10.1016/j.eurpolymj.2021.110904] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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7
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Pisani WA, Newman JK, Shukla MK. Multiscale Modeling of Polyamide 6 Using Molecular Dynamics and Micromechanics. Ind Eng Chem Res 2021. [DOI: 10.1021/acs.iecr.1c02440] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- William A. Pisani
- Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee 37830, United States
- Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, Mississippi 39180, United States
| | - John K. Newman
- Geotechnical and Structures Laboratory, US Army Engineer Research and Development Center, Vicksburg, Mississippi 39180, United States
| | - Manoj K. Shukla
- Environmental Laboratory, US Army Engineer Research and Development Center, Vicksburg, Mississippi 39180, United States
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8
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Multiscale Modeling of Epoxy-Based Nanocomposites Reinforced with Functionalized and Non-Functionalized Graphene Nanoplatelets. Polymers (Basel) 2021; 13:polym13121958. [PMID: 34199152 PMCID: PMC8231540 DOI: 10.3390/polym13121958] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/05/2021] [Accepted: 06/08/2021] [Indexed: 12/28/2022] Open
Abstract
The impact on the mechanical properties of an epoxy resin reinforced with pristine graphene nanoplatelets (GNP), highly concentrated graphene oxide (GO), and functionalized graphene oxide (FGO) has been investigated in this study. Molecular dynamics (MD) using a reactive force field (ReaxFF) has been employed in predicting the effective mechanical properties of the interphase region of the three nanocomposite materials at the nanoscale level. A systematic computational approach to simulate the reinforcing nanoplatelets and probe their influence on the mechanical properties of the epoxy matrix is established. The modeling results indicate a significant degradation of the in-plane elastic Young’s (decreased by ~89%) and shear (decreased by ~72.5%) moduli of the nanocomposite when introducing large amounts of oxygen and functional groups to the robust sp2 structure of the GNP. However, the wrinkled morphology of GO and FGO improves the nanoplatelet-matrix interlocking mechanism, which produces a significant improvement in the out-of-plane shear modulus (increased by 2 orders of magnitudes). The influence of the nanoplatelet content and aspect ratio on the mechanical response of the nanocomposites has also been determined in this study. Generally, the predicted mechanical response of the bulk nanocomposite materials demonstrates an improvement with increasing nanoplatelet content and aspect ratio. The results show good agreement with experimental data available from the literature.
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Demir B, Perli G, Chan KY, Duchet-Rumeau J, Livi S. Molecular-Level Investigation of Cycloaliphatic Epoxidised Ionic Liquids as a New Generation of Monomers for Versatile Poly(Ionic Liquids). Polymers (Basel) 2021; 13:polym13091512. [PMID: 34067227 PMCID: PMC8125863 DOI: 10.3390/polym13091512] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 04/30/2021] [Accepted: 05/03/2021] [Indexed: 11/16/2022] Open
Abstract
Recently, a new generation of polymerised ionic liquids with high thermal stability and good mechanical performances has been designed through novel and versatile cycloaliphatic epoxy-functionalised ionic liquids (CEILs). From these first promising results and unexplored chemical structures in terms of final properties of the PILs, a computational approach based on molecular dynamics simulations has been developed to generate polymer models and predict the thermo–mechanical properties (e.g., glass transition temperature and Young’s modulus) of experimentally investigated CEILs for producing multi-functional polymer materials. Here, a completely reproducible and reliable computational protocol is provided to design, test and tune poly(ionic liquids) based on epoxidised ionic liquid monomers for future multi-functional thermoset polymers.
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Affiliation(s)
- Baris Demir
- Centre for Theoretical and Computational Molecular Science, The Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
- Correspondence:
| | - Gabriel Perli
- Ingénierie des Matériaux Polymères, Université de Lyon, CNRS, UMR 5223, INSA Lyon, F-69621 Villeurbanne, France; (G.P.); (J.D.-R.); (S.L.)
| | - Kit-Ying Chan
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China;
| | - Jannick Duchet-Rumeau
- Ingénierie des Matériaux Polymères, Université de Lyon, CNRS, UMR 5223, INSA Lyon, F-69621 Villeurbanne, France; (G.P.); (J.D.-R.); (S.L.)
| | - Sébastien Livi
- Ingénierie des Matériaux Polymères, Université de Lyon, CNRS, UMR 5223, INSA Lyon, F-69621 Villeurbanne, France; (G.P.); (J.D.-R.); (S.L.)
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10
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Preparation, Properties and Mechanisms of Carbon Fiber/Polymer Composites for Thermal Management Applications. Polymers (Basel) 2021; 13:polym13010169. [PMID: 33466509 PMCID: PMC7796458 DOI: 10.3390/polym13010169] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 12/30/2020] [Accepted: 12/31/2020] [Indexed: 11/17/2022] Open
Abstract
With the increasing integration and miniaturization of electronic devices, heat dissipation has become a major challenge. The traditional printed polymer circuit board can no longer meet the heat dissipation demands of microelectronic equipment. If the heat cannot be removed quickly and effectively, the efficiency of the devices will be decreased and their lifetime will be shortened. In addition, the development of the aerospace, automobiles, light emitting diode (LED{ TA \1 "LED; lightemitting diode" \s "LED" \c 1 }) and energy harvesting and conversion has gradually increased the demand for low-density and high thermal conductive materials. In recent years, carbon fiber (CF{ TA \1 "CF; carbon fiber" \c 1 }) has been widely used for the preparation of polymer composites due to its good mechanical property and ultra-high thermal conductivity. CF materials easily form thermal conduction paths through polymer composites to improve the thermal conductivity. This paper describes the research progress, thermal conductivity mechanisms, preparation methods, factors influencing thermal conductivity and provides relevant suggestions for the development of CF composites for thermal management.
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11
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Surblys D, Matsubara H, Kikugawa G, Ohara T. Application of atomic stress to compute heat flux via molecular dynamics for systems with many-body interactions. Phys Rev E 2019; 99:051301. [PMID: 31212446 DOI: 10.1103/physreve.99.051301] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Indexed: 06/09/2023]
Abstract
Although the computation of heat flux and thermal conductivity either via Fourier's law or the Green-Kubo relation has become a common task in molecular dynamics simulation, contributions of three-body and larger many-body interactions have always proved problematic to compute. In recent years, due to the success when applying to pressure tensor computation, atomic stress approximation has been widely used to calculate heat flux, where the lammps molecular dynamics package is the most prominent propagator. We demonstrated that the atomic stress approximation, while adequate for obtaining pressure, produces erroneous results in the case of heat flux when applied to systems with many-body interactions, such as angle, torsion, or improper potentials. This also produces incorrect thermal conductivity values. To remedy this deficiency, by starting from a strict formulation of heat flux with many-body interactions, we reworked the atomic stress definition which resulted in only a simple modification. We modified the lammps package accordingly to demonstrate that the new atomic stress approximation produces excellent results close to that of a rigid formulation.
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Affiliation(s)
- Donatas Surblys
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Hiroki Matsubara
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Gota Kikugawa
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
| | - Taku Ohara
- Institute of Fluid Science, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai 980-8577, Japan
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12
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Xue Y, Li X, Wang H, Zhang D, Chen Y. Thermal conductivity improvement in electrically insulating silicone rubber composites by the construction of hybrid three-dimensional filler networks with boron nitride and carbon nanotubes. J Appl Polym Sci 2018. [DOI: 10.1002/app.46929] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Affiliation(s)
- Yang Xue
- University of Chinese Academy of Sciences; Beijing 100049 China
- State Key Laboratory of Multi-Phase Complex Systems; Institute of Process Engineering, Chinese Academy of Sciences; Beijing 100190 China
| | - Xiaofei Li
- University of Chinese Academy of Sciences; Beijing 100049 China
- State Key Laboratory of Multi-Phase Complex Systems; Institute of Process Engineering, Chinese Academy of Sciences; Beijing 100190 China
| | - Haosheng Wang
- State Key Laboratory of Multi-Phase Complex Systems; Institute of Process Engineering, Chinese Academy of Sciences; Beijing 100190 China
| | - Donghai Zhang
- State Key Laboratory of Multi-Phase Complex Systems; Institute of Process Engineering, Chinese Academy of Sciences; Beijing 100190 China
| | - Yunfa Chen
- State Key Laboratory of Multi-Phase Complex Systems; Institute of Process Engineering, Chinese Academy of Sciences; Beijing 100190 China
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13
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Yu C, Xu Z, Wang Y, Chen S, Miao M, Zhang D. Synthesis and Degradation Mechanism of Self-Cured Hyperbranched Epoxy Resins from Natural Citric Acid. ACS OMEGA 2018; 3:8141-8148. [PMID: 31458951 PMCID: PMC6644903 DOI: 10.1021/acsomega.8b01216] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/02/2018] [Accepted: 07/11/2018] [Indexed: 05/09/2023]
Abstract
Rapid and highly efficient degradation of cured thermoset epoxy resins is a major challenge to scientists. Here, degradable self-cured hyperbranched epoxy resins (DSHE-n, n = 1, 2, and 3) were synthesized by a reaction between 3-isocyanato-4-methyl-epoxy-methylphenylcarbamate and degradable epoxy-ended hyperbranched polyester (DEHP-n) prepared from maleicanhydride, citric acid, and epichlorohydrin. The chemical structure of DSHE-n was characterized by Fourier transform infrared and 1H NMR spectra. With an increase in DSHE-n molecular weight, the adhesion strength of self-cured DSHE-n films increases distinctly from class 1 to 4, and their pencil hardness remains about class B-2B. The study on the self-cured behavior and mechanism of DSHE-n shows that the carbamate group of the DSHE-n is decomposed into diamine group to react with epoxy group and form a cross-linked structure. The self-cured DSHE-n films were degraded completely in 2 h at 90 °C in the mixed solution of hydrogen peroxide (H2O2) and N,N-dimethylformamide under atmospheric pressure and produced the raw material citric acid, indicating good degradation performance and recyclable property of DSHE-n.
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Affiliation(s)
- Chenglong Yu
- Key
Laboratory of Catalysis and Materials Science of the State Ethnic
Affairs Commission & Ministry of Education, South-Central University for Nationalities, Wuhan, Hubei 430074, China
| | - Zejun Xu
- Key
Laboratory of Catalysis and Materials Science of the State Ethnic
Affairs Commission & Ministry of Education, South-Central University for Nationalities, Wuhan, Hubei 430074, China
| | - Yimei Wang
- Key
Laboratory of Catalysis and Materials Science of the State Ethnic
Affairs Commission & Ministry of Education, South-Central University for Nationalities, Wuhan, Hubei 430074, China
| | - Sufang Chen
- Key
Laboratory for Green Chemical Process of Ministry of Education, Wuhan Institute of Technology, Wuhan, Hubei 430073, China
| | - Menghe Miao
- CSIRO
Manufacturing, 75 Pigdons
Road, Waurn Ponds, Victoria 3216, Australia
| | - Daohong Zhang
- Key
Laboratory of Catalysis and Materials Science of the State Ethnic
Affairs Commission & Ministry of Education, South-Central University for Nationalities, Wuhan, Hubei 430074, China
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14
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Xie Q, Fu K, Liang S, Liu B, Lu L, Yang X, Huang Z, Lü F. Micro-Structure and Thermomechanical Properties of Crosslinked Epoxy Composite Modified by Nano-SiO₂: A Molecular Dynamics Simulation. Polymers (Basel) 2018; 10:E801. [PMID: 30960726 PMCID: PMC6403537 DOI: 10.3390/polym10070801] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 07/19/2018] [Accepted: 07/19/2018] [Indexed: 01/15/2023] Open
Abstract
Establishing the relationship among the composition, structure and property of the associated materials at the molecular level is of great significance to the rational design of high-performance electrical insulating Epoxy Resin (EP) and its composites. In this paper, the molecular models of pure Diglycidyl Ether of Bisphenol A resin/Methyltetrahydrophthalic Anhydride (DGEBA/MTHPA) and their nanocomposites containing nano-SiO₂ with different particle sizes were constructed. The effects of nano-SiO₂ dopants and the crosslinked structure on the micro-structure and thermomechanical properties were investigated using molecular dynamics simulations. The results show that the increase of crosslinking density enhances the thermal and mechanical properties of pure EP and EP nanocomposites. In addition, doping nano-SiO₂ particles into EP can effectively improve the properties, as well, and the effectiveness is closely related to the particle size of nano-SiO₂. Moreover, the results indicate that the glass transition temperature (Tg) value increases with the decreasing particle size. Compared with pure EP, the Tg value of the 6.5 Å composite model increases by 6.68%. On the contrary, the variation of the Coefficient of Thermal Expansion (CTE) in the glassy state demonstrates the opposite trend compared with Tg. The CTE of the 10 Å composite model is the lowest, which is 7.70% less than that of pure EP. The mechanical properties first increase and then decrease with the decreasing particle size. Both the Young's modulus and shear modulus reach the maximum value at 7.6 Å, with noticeable increases by 12.60% and 8.72%, respectively compared to the pure EP. In addition, the thermal and mechanical properties are closely related to the Fraction of Free Volume (FFV) and Mean Squared Displacement (MSD). The crosslinking process and the nano-SiO₂ doping reduce the FFV and MSD value in the model, resulting in better thermal and mechanical properties.
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Affiliation(s)
- Qing Xie
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071000, China.
| | - Kexin Fu
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071000, China.
| | - Shaodong Liang
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071000, China.
| | - Bowen Liu
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071000, China.
| | - Lu Lu
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071000, China.
| | - Xueming Yang
- Department of Power Engineering, North China Electric Power University, Baoding 071003, China.
| | - Zhengyong Huang
- State Key Laboratory of Power Transmission Equipment & System Security and New Technology, Chongqing University, Chongqing 400044, China.
| | - Fangcheng Lü
- State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources, North China Electric Power University, Baoding 071000, China.
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