51
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Rossi G, Giannakopoulos I, Monticelli L, Rostedt NKJ, Puisto SR, Lowe C, Taylor AC, Vattulainen I, Ala-Nissila T. A MARTINI Coarse-Grained Model of a Thermoset Polyester Coating. Macromolecules 2011. [DOI: 10.1021/ma200788a] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Giulia Rossi
- Department of Applied Physics, Aalto University School of Science, P.O. Box 11000, FI-00076 AALTO, Helsinki, Finland
| | - Ioannis Giannakopoulos
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London 6 SW7 2AZ, United Kingdom
| | - Luca Monticelli
- INSERM, UMR-S 665, DSIMB, 6 rue Alexandre Cabanel, 75015 Paris, France
- Université Paris Diderot −Paris 7, UFR Sciences du Vivant, Paris, France
- INTS, Paris, France
| | - Niko K. J. Rostedt
- Matox Ltd., Pembroke House, 36-37 Pembroke Street, Oxford OX1 1BP, United Kingdom
| | - Sakari R. Puisto
- Matox Ltd., Pembroke House, 36-37 Pembroke Street, Oxford OX1 1BP, United Kingdom
| | - Chris Lowe
- Becker Industrial Coatings Ltd., Goodlass Road, Speke, Liverpool L24 9HJ, United Kingdom
| | - Ambrose C. Taylor
- Department of Mechanical Engineering, Imperial College London, South Kensington Campus, London 6 SW7 2AZ, United Kingdom
| | - Ilpo Vattulainen
- Department of Physics, Tampere University of Technology, P.O. Box 692, FI-33101, Tampere, Finland
- MEMPHYS, Center of Biomembrane Physics, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark
| | - Tapio Ala-Nissila
- Department of Applied Physics, Aalto University School of Science, P.O. Box 11000, FI-00076 AALTO, Helsinki, Finland
- Department of Physics, Brown University, P.O. Box 1843, Providence, Rhode Island 02912-1843, United States
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52
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Chen K, Schweizer KS. Theory of Yielding, Strain Softening, and Steady Plastic Flow in Polymer Glasses under Constant Strain Rate Deformation. Macromolecules 2011. [DOI: 10.1021/ma200436w] [Citation(s) in RCA: 97] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kang Chen
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China
| | - Kenneth S. Schweizer
- Department of Materials Science, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801, United States
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53
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Warren M, Rottler J. Deformation-induced accelerated dynamics in polymer glasses. J Chem Phys 2010; 133:164513. [DOI: 10.1063/1.3505149] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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54
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55
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Hoy RS, O'Hern CS. Viscoplasticity and large-scale chain relaxation in glassy-polymeric strain hardening. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 82:041803. [PMID: 21230304 DOI: 10.1103/physreve.82.041803] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2010] [Revised: 08/06/2010] [Indexed: 05/30/2023]
Abstract
A simple theory for glassy-polymeric mechanical response that accounts for large-scale chain relaxation is presented. It captures the crossover from perfect-plastic response to Gaussian strain hardening as the degree of polymerization N increases, without invoking entanglements. By relating hardening to interactions on the scale of monomers and chain segments, we correctly predict its magnitude. Strain-activated relaxation arising from the need to maintain constant chain contour length reduces the characteristic relaxation time by a factor ~εN during active deformation at strain rate ε. This prediction is consistent with results from recent experiments and simulations, and we suggest how it may be further tested experimentally.
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Affiliation(s)
- Robert S Hoy
- Department of Mechanical Engineering and Materials Science, Yale University, New Haven, Connecticut 06520-8286, USA.
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56
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Chen K, Schweizer KS. Theory of aging, rejuvenation, and the nonequilibrium steady state in deformed polymer glasses. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2010; 82:041804. [PMID: 21230305 DOI: 10.1103/physreve.82.041804] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Indexed: 05/30/2023]
Abstract
The nonlinear Langevin equation theory of segmental relaxation, elasticity, and mechanical response of polymer glasses is extended to describe the coupled effects of physical aging, mechanical rejuvenation, and thermal history. The key structural variable is the amplitude of density fluctuations, and segmental dynamics proceeds via stress-modified activated barrier hopping on a dynamic free-energy profile. Mechanically generated disorder (rejuvenation) is quantified by a dissipative work argument and increases the amplitude of density fluctuations, thereby speeding up relaxation beyond that induced by the landscape tilting mechanism. The theory makes testable predictions for the time evolution and nonequilibrium steady state of the alpha relaxation time, density fluctuation amplitude, elastic modulus, and other properties. Model calculations reveal a rich dependence of these quantities on preaging time, applied stress, and temperature that reflects the highly nonlinear competition between physical aging and mechanical disordering. Thermal history is "erased" in the long-time limit, although the nonequilibrium steady state is not the literal "fully rejuvenated" freshly quenched glass. The present work provides the conceptual foundation for a quantitative treatment of the nonlinear mechanical response of polymer glasses under a variety of deformation protocols.
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Affiliation(s)
- Kang Chen
- Center for Soft Condensed Matter Physics and Interdisciplinary Research, Soochow University, Suzhou 215006, China
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57
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Lee HN, Ediger MD. Interaction between physical aging, deformation, and segmental mobility in poly(methyl methacrylate) glasses. J Chem Phys 2010; 133:014901. [DOI: 10.1063/1.3450318] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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58
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Lee HN, Ediger MD. Mechanical Rejuvenation in Poly(methyl methacrylate) Glasses? Molecular Mobility after Deformation. Macromolecules 2010. [DOI: 10.1021/ma1006649] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hau-Nan Lee
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - M. D. Ediger
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
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59
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Warren M, Rottler J. Microscopic view of accelerated dynamics in deformed polymer glasses. PHYSICAL REVIEW LETTERS 2010; 104:205501. [PMID: 20867036 DOI: 10.1103/physrevlett.104.205501] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/28/2009] [Indexed: 05/29/2023]
Abstract
A molecular level analysis of segmental trajectories obtained from molecular dynamics simulations is used to obtain the full relaxation time spectrum in aging polymer glasses subject to three different deformation protocols. As in experiments, dynamics can be accelerated by several orders of magnitude, and a narrowing of the distribution of relaxation times during creep is directly observed. Additionally, the acceleration factor describing the transformation of the relaxation time distributions is computed and found to obey a universal dependence on the strain, independent of age and deformation protocol.
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Affiliation(s)
- Mya Warren
- Department of Physics and Astronomy, The University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia, V6T 1Z1, Canada
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60
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Hoy RS, Robbins MO. Strain hardening in bidisperse polymer glasses: Separating the roles of chain orientation and interchain entanglement. J Chem Phys 2009; 131:244901. [DOI: 10.1063/1.3276800] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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61
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Chen K, Saltzman EJ, Schweizer KS. Segmental dynamics in polymers: from cold melts to ageing and stressed glasses. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:503101. [PMID: 21836211 DOI: 10.1088/0953-8984/21/50/503101] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Recent progress in developing statistical mechanical theories of supercooled polymer melts and glasses is reviewed. The focus is on those approaches that are either explicitly formulated for polymers, or are applications of more generic theories to interpret polymeric phenomena. These include two configurational entropy theories, a percolated free volume distribution model, and the activated barrier hopping nonlinear Langevin theory. Both chemically-specific and universal aspects are discussed. After a brief summary of classic phenomenological approaches, a discussion of the relevant length scales and key experimental phenomena in both the supercooled liquid and glassy solid state is presented including ageing and nonlinear mechanical response. The central concepts that underlie the theories in the molten state are then summarized and key predictions discussed, including the glass transition in oriented polymer liquids and deformed rubber networks. Physical ageing occurs in the nonequilibrium glass, and theories for its consequences on the alpha relaxation are discussed. Very recent progress in developing a segment scale theory for the dramatic effects of external stress on polymer glasses, including acceleration of relaxation, yielding, plastic flow and strain hardening, is summarized. The article concludes with a discussion of outstanding theoretical challenges.
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62
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Rottler J. Fracture in glassy polymers: a molecular modeling perspective. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2009; 21:463101. [PMID: 21715863 DOI: 10.1088/0953-8984/21/46/463101] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Over the past 25 years, molecular modeling and simulations have provided important insights into the physics of deformation and fracture of glassy polymers. This review presents an overview of key results discussed in the context of experimentally observed polymer behavior. Both atomistic and coarse-grained polymer models have been used in different deformation protocols to study elastic properties, shear yielding, creep, physical aging, strain hardening and crazing. Simulations reproduce most of the macroscopic features of plasticity in polymer glasses such as stress-strain relations and creep response, and reveal information about the underlying atomistic processes. Trends of the shear yield stress with loading conditions, temperature and strain rate, and the atomistic dynamics under load have been systematically explored. Most polymers undergo physical aging, which leads to a history-dependent mechanical response. Simulations of strain hardening and crazing demonstrate the nature of polymer entanglements in the glassy state and the role of local plasticity and provide insight into the origin of fracture toughness of amorphous polymers.
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Affiliation(s)
- Jörg Rottler
- Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, BC, V6T 1Z1, Canada
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63
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Lee HN, Paeng K, Swallen SF, Ediger MD, Stamm RA, Medvedev GA, Caruthers JM. Molecular mobility of poly(methyl methacrylate) glass during uniaxial tensile creep deformation. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/polb.21774] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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64
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Lee HN, Riggleman RA, de Pablo JJ, Ediger MD. Deformation-Induced Mobility in Polymer Glasses during Multistep Creep Experiments and Simulations. Macromolecules 2009. [DOI: 10.1021/ma900394n] [Citation(s) in RCA: 95] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hau-Nan Lee
- Department of Chemistry
- Department of Chemical and Biological Engineering
- University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Robert A. Riggleman
- Department of Chemistry
- Department of Chemical and Biological Engineering
- University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - Juan J. de Pablo
- Department of Chemistry
- Department of Chemical and Biological Engineering
- University of Wisconsin-Madison, Madison, Wisconsin 53706
| | - M. D. Ediger
- Department of Chemistry
- Department of Chemical and Biological Engineering
- University of Wisconsin-Madison, Madison, Wisconsin 53706
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65
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Riggleman RA, Toepperwein GN, Papakonstantopoulos GJ, de Pablo JJ. Dynamics of a Glassy Polymer Nanocomposite during Active Deformation. Macromolecules 2009. [DOI: 10.1021/ma802865n] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Robert A. Riggleman
- Department of Chemical Engineering; University of California, Santa Barbara, California 93106; Department of Chemical and Biological Engineering, University of Wisconsin, Madison, Wisconsin 53706; and Analytical and Systems Division, Arkema Inc. R&D Center, King of Prussia, Pennsylvania 19406
| | - Gregory N. Toepperwein
- Department of Chemical Engineering; University of California, Santa Barbara, California 93106; Department of Chemical and Biological Engineering, University of Wisconsin, Madison, Wisconsin 53706; and Analytical and Systems Division, Arkema Inc. R&D Center, King of Prussia, Pennsylvania 19406
| | - George J. Papakonstantopoulos
- Department of Chemical Engineering; University of California, Santa Barbara, California 93106; Department of Chemical and Biological Engineering, University of Wisconsin, Madison, Wisconsin 53706; and Analytical and Systems Division, Arkema Inc. R&D Center, King of Prussia, Pennsylvania 19406
| | - Juan J. de Pablo
- Department of Chemical Engineering; University of California, Santa Barbara, California 93106; Department of Chemical and Biological Engineering, University of Wisconsin, Madison, Wisconsin 53706; and Analytical and Systems Division, Arkema Inc. R&D Center, King of Prussia, Pennsylvania 19406
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66
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Liu J, Cao D, Zhang L, Wang W. Time−Temperature and Time−Concentration Superposition of Nanofilled Elastomers: A Molecular Dynamics Study. Macromolecules 2009. [DOI: 10.1021/ma802744e] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Jun Liu
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, and Division of Molecular and Materials Simulation, Key Laboratory for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, P. R. China
| | - Dapeng Cao
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, and Division of Molecular and Materials Simulation, Key Laboratory for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, P. R. China
| | - Liqun Zhang
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, and Division of Molecular and Materials Simulation, Key Laboratory for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, P. R. China
| | - Wenchuan Wang
- Key Laboratory of Beijing City on Preparation and Processing of Novel Polymer Materials, and Division of Molecular and Materials Simulation, Key Laboratory for Nanomaterials, Ministry of Education, Beijing University of Chemical Technology, Beijing 100029, P. R. China
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67
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Chen K, Schweizer KS. Suppressed segmental relaxation as the origin of strain hardening in polymer glasses. PHYSICAL REVIEW LETTERS 2009; 102:038301. [PMID: 19257400 DOI: 10.1103/physrevlett.102.038301] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2008] [Indexed: 05/27/2023]
Abstract
A nanometer scale dynamical theory is proposed for the large amplitude strain hardening phenomenon in polymer glasses. The new physical picture is that external deformation induces anisotropic chain conformations, which modifies interchain packing, resulting in density fluctuation suppression and intensification of localizing dynamical constraints and activation barriers. The resulting stresses are of intermolecular origin and arise primarily from prolongation of segmental relaxation, not single chain entropic rubber elasticity. Theoretical predictions for the magnitude, temperature, and deformation rate dependence of the hardening modulus are consistent with experiments and simulations.
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Affiliation(s)
- Kang Chen
- Department of Materials Science, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801, USA
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68
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Lee HN, Paeng K, Swallen SF, Ediger MD. Direct Measurement of Molecular Mobility in Actively Deformed Polymer Glasses. Science 2009; 323:231-4. [DOI: 10.1126/science.1165995] [Citation(s) in RCA: 235] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
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69
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Chen K, Schweizer KS, Stamm R, Lee E, Caruthers JM. Theory of nonlinear creep in polymer glasses. J Chem Phys 2008; 129:184904. [DOI: 10.1063/1.3008059] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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70
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Chen K, Schweizer KS. Microscopic Constitutive Equation Theory for the Nonlinear Mechanical Response of Polymer Glasses. Macromolecules 2008. [DOI: 10.1021/ma800778v] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Kang Chen
- Department of Materials Science and Engineering, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801
| | - Kenneth S. Schweizer
- Department of Materials Science and Engineering, University of Illinois, 1304 West Green Street, Urbana, Illinois 61801
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