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Martini F, Carignani E, Nardelli F, Rossi E, Borsacchi S, Cettolin M, Susanna A, Geppi M, Calucci L. Glassy and Polymer Dynamics of Elastomers by 1H Field-Cycling NMR Relaxometry: Effects of Cross-Linking. Macromolecules 2020; 53:10028-10039. [PMID: 33250523 PMCID: PMC7690040 DOI: 10.1021/acs.macromol.0c01439] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 10/20/2020] [Indexed: 11/28/2022]
Abstract
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1H spin lattice relaxation
rate (R1) dispersions were acquired by
field-cycling (FC) NMR relaxometry
between 0.01 and 35 MHz over a wide temperature range on polyisoprene
(IR), polybutadiene (BR), and poly(styrene-co-butadiene)
(SBR) rubbers, obtained by vulcanization under different conditions,
and on the corresponding uncured elastomers. By exploiting the frequency–temperature
superposition principle, χ″(ωτs) master curves were constructed by shifting the total FC NMR susceptibility,
χ″(ω) = ωR1(ω),
curves along the frequency axis by the correlation times for glassy
dynamics, τs. Longer τs values and,
correspondingly, higher glass transition temperatures were determined
for the sulfur-cured elastomers with respect to the uncured ones,
which increased by increasing the cross-link density, whereas no significant
changes were found for fragility. The contribution of polymer dynamics,
χpol″(ω), to χ″(ω)
was singled out by subtracting the contribution of glassy dynamics,
χglass″(ω), well represented using a
Cole–Davidson spectral density. For all elastomers, χpol″(ω) was found to represent a small fraction, on the order of
0.05–0.14, of the total χ″(ω), which did
not show a significant dependence on cross-link density. In the investigated
temperature and frequency ranges, polymer dynamics was found to encompass
regimes I (Rouse dynamics) and II (constrained Rouse dynamics) of
the tube reptation model for the uncured elastomers and only regime
I for the vulcanized ones. This is clear evidence that chemical cross-links
impose constraints on chain dynamics on a larger space and time scale
than free Rouse modes.
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Affiliation(s)
- Francesca Martini
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.,Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Elisa Carignani
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.,Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Francesca Nardelli
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.,Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Elena Rossi
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy
| | - Silvia Borsacchi
- Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
| | | | | | - Marco Geppi
- Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via G. Moruzzi 13, 56124 Pisa, Italy.,Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
| | - Lucia Calucci
- Istituto di Chimica dei Composti OrganoMetallici, Consiglio Nazionale Delle Ricerche, Via G. Moruzzi 1, 56124 Pisa, Italy
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Robertson CG, Vaikuntam SR, Heinrich G. A Nonequilibrium Model for Particle Networking/Jamming and Time-Dependent Dynamic Rheology of Filled Polymers. Polymers (Basel) 2020; 12:E190. [PMID: 31936848 PMCID: PMC7023509 DOI: 10.3390/polym12010190] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/02/2020] [Accepted: 01/05/2020] [Indexed: 11/16/2022] Open
Abstract
We describe an approach for modeling the filler network formation kinetics of particle-reinforced rubbery polymers-commonly called filler flocculation-that was developed by employing parallels between deformation effects in jammed particle systems and the influence of temperature on glass-forming materials. Experimental dynamic viscosity results were obtained concerning the strain-induced particle network breakdown and subsequent time-dependent reformation behavior for uncross-linked elastomers reinforced with carbon black and silica nanoparticles. Using a relaxation time function that depends on both actual dynamic strain amplitude and fictive (structural) strain, the model effectively represented the experimental data for three different levels of dynamic strain down-jump with a single set of parameters. This fictive strain model for filler networking is analogous to the established Tool-Narayanaswamy-Moynihan model for structural relaxation (physical aging) of nonequilibrium glasses. Compared to carbon black, precipitated silica particles without silane surface modification exhibited a greater overall extent of filler networking and showed more self-limiting behavior in terms of network formation kinetics in filled ethylene-propylene-diene rubber (EPDM). The EPDM compounds with silica or carbon black filler were stable during the dynamic shearing and recovery experiments at 160 °C, whereas irreversible dynamic modulus increases were noted when the polymer matrix was styrene-butadiene rubber (SBR), presumably due to branching/cross-linking of SBR in the rheometer. Care must be taken when measuring and interpreting the time-dependent filler networking in unsaturated elastomers at high temperatures.
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Affiliation(s)
| | - Sankar Raman Vaikuntam
- Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany; (S.R.V.); (G.H.)
| | - Gert Heinrich
- Leibniz-Institut für Polymerforschung Dresden e.V., 01069 Dresden, Germany; (S.R.V.); (G.H.)
- Institut für Textilmaschinen und Textile Hochleistungswerkstofftechnik, Technische Universität Dresden, 01069 Dresden, Germany
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Warasitthinon N, Robertson CG. INTERPRETATION OF THE TANδ PEAK HEIGHT FOR PARTICLE-FILLED RUBBER AND POLYMER NANOCOMPOSITES WITH RELEVANCE TO TIRE TREAD PERFORMANCE BALANCE. RUBBER CHEMISTRY AND TECHNOLOGY 2018. [DOI: 10.5254/rct.18.82608] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
ABSTRACT
The aim of this research is to clarify the meaning of the peak height for the viscoelastic loss tangent (tanδ) in the glass transition region of particle-filled rubber, polymer nanocomposites, and polymer systems in general. Filler, oil, and curative loadings were systematically varied in a model styrene-butadiene rubber formulation with carbon black as the reinforcing filler. The dynamic mechanical responses of these compounds enabled a detailed study of the glass-to-rubber softening transition, which is known to play an important role with respect to the balance of traction, handling, and rolling resistance characteristics of tire treads. From the temperature-dependent viscoelastic results that were acquired at fixed frequency and small dynamic strain, it was demonstrated that a higher peak value for tanδ was correlated with a lower dynamic modulus in the rubbery state. Adjusting filler volume fraction was found to be an effective way of changing the rubbery modulus and hence the tanδ peak height. It was furthermore verified that such a correlation is a universal material-independent viscoelastic effect by mathematically producing a similar trend by varying the rubbery modulus parameter in the Havriliak–Negami viscoelastic model. This investigation also showed why glass transition temperature should be determined from the position of the loss modulus peak and not the tanδ peak. Cure behavior, tensile stress–strain properties, and extent of filler networking (Payne effect) for these rubber compounds will additionally be discussed.
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Patil PN, Roilo D, Brusa RS, Miotello A, Aghion S, Ferragut R, Checchetto R. Free volumes and gas transport in polymers: amine-modified epoxy resins as a case study. Phys Chem Chem Phys 2016; 18:3817-24. [PMID: 26762568 DOI: 10.1039/c5cp07149f] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The CO2 transport process was studied in a series of amine-modified epoxy resins having different cross-linking densities but the same chemical environment for the penetrant molecules. Positron Annihilation Lifetime Spectroscopy (PALS) was used to monitor the free volume structure of the samples and experimentally evaluate their fractional free volume fh(T) and its temperature evolution. The analysis of the free volume hole size distribution showed that all the holes have a size large enough to accommodate the penetrant molecules at temperatures T above the glass transition temperature Tg. The measured gas diffusion constants at T > Tg have been reproduced in the framework of the free volume theory of diffusion using a novel procedure based on the use of fh(T) as an input experimental parameter.
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Affiliation(s)
- Pushkar N Patil
- Department of Physics, University of Trento, via Sommarive 14, I-38123 Povo, TN, Italy.
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Xie SJ, Qian HJ, Lu ZY. The glass transition of polymers with different side-chain stiffness confined in free-standing thin films. J Chem Phys 2015; 142:074902. [DOI: 10.1063/1.4908047] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Shi-Jie Xie
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Hu-Jun Qian
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
| | - Zhong-Yuan Lu
- State Key Laboratory of Supramolecular Structure and Materials, Institute of Theoretical Chemistry, Jilin University, Changchun 130023, China
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Rath SK, Aswal VK, Sharma C, Joshi K, Patri M, Harikrishnan G, Khakhar DV. Mechanistic origins of multi-scale reinforcements in segmented polyurethane-clay nanocomposites. POLYMER 2014. [DOI: 10.1016/j.polymer.2014.08.035] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Stathopoulos AT, Kyritsis A, Ferrer GG, Gómez Ribelles JL, Christodoulides C, Pissis P. Cooperative Segmental Motions in Ethyl Acrylate/Triethylene Glycol Dimethacrylate Copolymer Networks Studied by Dielectric Techniques. Macromolecules 2011. [DOI: 10.1021/ma201755y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Andreas T. Stathopoulos
- Department of Physics, National Technical University of Athens, Zografou Campus, 15780 Athens, Greece
| | - Apostolos Kyritsis
- Department of Physics, National Technical University of Athens, Zografou Campus, 15780 Athens, Greece
| | - Gloria Gallego Ferrer
- Centro de Biomateriales e Ingeniería Tisular, Universidad Politecnica de Valencia, P.O. Box 22012, E-46071 Valencia, Spain
- Regenerative Medicine Unit, Centro de Investigación Príncipe Felipe, Autopista del Saler 16, 46013 Valencia, Spain
- CIBER en Bioingeniería, Biomateriales y Nanomedicina, Valencia, Spain
| | - José Luis Gómez Ribelles
- Centro de Biomateriales e Ingeniería Tisular, Universidad Politecnica de Valencia, P.O. Box 22012, E-46071 Valencia, Spain
- Regenerative Medicine Unit, Centro de Investigación Príncipe Felipe, Autopista del Saler 16, 46013 Valencia, Spain
- CIBER en Bioingeniería, Biomateriales y Nanomedicina, Valencia, Spain
| | - Costas Christodoulides
- Department of Physics, National Technical University of Athens, Zografou Campus, 15780 Athens, Greece
| | - Polycarpos Pissis
- Department of Physics, National Technical University of Athens, Zografou Campus, 15780 Athens, Greece
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Tonpheng B, Yu J, Andersson O. Effects of cross-links, pressure and temperature on the thermal properties and glass transition behaviour of polybutadiene. Phys Chem Chem Phys 2011; 13:15047-54. [DOI: 10.1039/c1cp20785g] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Robertson CG, Hogan TE, Rackaitis M, Puskas JE, Wang X. Effect of nanoscale confinement on glass transition of polystyrene domains from self-assembly of block copolymers. J Chem Phys 2010; 132:104904. [DOI: 10.1063/1.3337910] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Putz KW, Palmeri MJ, Cohn RB, Andrews R, Brinson LC. Effect of Cross-Link Density on Interphase Creation in Polymer Nanocomposites. Macromolecules 2008. [DOI: 10.1021/ma800830p] [Citation(s) in RCA: 193] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Karl W. Putz
- Department of Mechanical Engineering, Department of Materials Science and Engineering, and MRSEC−REU Program, Northwestern University, Evanston, Illinois 60208, and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506
| | - Marc J. Palmeri
- Department of Mechanical Engineering, Department of Materials Science and Engineering, and MRSEC−REU Program, Northwestern University, Evanston, Illinois 60208, and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506
| | - Rachel B. Cohn
- Department of Mechanical Engineering, Department of Materials Science and Engineering, and MRSEC−REU Program, Northwestern University, Evanston, Illinois 60208, and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506
| | - Rodney Andrews
- Department of Mechanical Engineering, Department of Materials Science and Engineering, and MRSEC−REU Program, Northwestern University, Evanston, Illinois 60208, and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506
| | - L. Catherine Brinson
- Department of Mechanical Engineering, Department of Materials Science and Engineering, and MRSEC−REU Program, Northwestern University, Evanston, Illinois 60208, and Center for Applied Energy Research, University of Kentucky, Lexington, Kentucky 40506
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Tran TA, Saïd S, Grohens Y. Nanoscale Characteristic Length at the Glass Transition in Confined Syndiotactic Poly(methyl methacrylate). Macromolecules 2005. [DOI: 10.1021/ma0487296] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tuan Anh Tran
- Laboratoire Polymères, Propriétés aux Interfaces et Composites (L2PIC), Centre de Recherche BP 92116, Rue de Saint Maudé, 56321 Lorient Cedex, France
| | - Sylvère Saïd
- Laboratoire Polymères, Propriétés aux Interfaces et Composites (L2PIC), Centre de Recherche BP 92116, Rue de Saint Maudé, 56321 Lorient Cedex, France
| | - Yves Grohens
- Laboratoire Polymères, Propriétés aux Interfaces et Composites (L2PIC), Centre de Recherche BP 92116, Rue de Saint Maudé, 56321 Lorient Cedex, France
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Robertson CG, Rademacher CM. Coupling Model Interpretation of Thermorheological Complexity in Polybutadienes with Varied Microstructure. Macromolecules 2004. [DOI: 10.1021/ma0482415] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Christopher G. Robertson
- Bridgestone Americas Center for Research and Technology, 1200 Firestone Parkway, Akron, Ohio 44317-0001
| | - Christine M. Rademacher
- Bridgestone Americas Center for Research and Technology, 1200 Firestone Parkway, Akron, Ohio 44317-0001
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