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De Nicola A, Touloupidis V, Kanellopoulos V, Albunia AR, Milano G. A combined experimental and molecular simulation study on stress generation phenomena during the Ziegler-Natta polyethylene catalyst fragmentation process. NANOSCALE ADVANCES 2022; 4:5178-5188. [PMID: 36504732 PMCID: PMC9680958 DOI: 10.1039/d2na00406b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Accepted: 10/14/2022] [Indexed: 06/17/2023]
Abstract
The morphology of particles obtained under different pre-polymerization conditions has been connected to the stress generation mechanism at the polymer/catalyst interface. A combination of experimental characterization techniques and atomistic molecular dynamics simulations allowed a systematic investigation of experimental conditions leading to a certain particle morphology, and hence to a final polymer with specific features. Atomistic models of nascent polymer phases in contact with magnesium dichloride surfaces have been developed and validated. Using these detailed models, in the framework of McKenna's hypothesis, the pressure increase due to the polymerization reaction has been calculated under different conditions and is in good agreement with experimental scenarios. This molecular scale knowledge and the proposed investigation strategy would allow the pre-polymerization conditions to be better defined and the properties of the nascent polymer to be tuned, ensuring proper operability along the whole polymer production process.
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Affiliation(s)
- Antonio De Nicola
- Scuola Superiore Meridionale Largo San Marcellino 10 80132 Napoli Italy
| | - Vasileios Touloupidis
- Innovation & Technology, Borealis Polyolefine GmbH St. Peter Strasse 25 4021 Linz Austria
| | | | - Alexandra R Albunia
- Innovation & Technology, Borealis Polyolefine GmbH St. Peter Strasse 25 4021 Linz Austria
| | - Giuseppe Milano
- Dipartimento di Ingegneria Chimica dei Materiali e della Produzione Industriale, Università degli Studi di Napoli Federico II Piazzale V. Tecchio 80 80125 Napoli Italy
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2
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Yamamoto T. Chiral selecting crystallization of helical polymers: A molecular dynamics simulation for the POM-like bare helix. J Chem Phys 2022; 157:014901. [DOI: 10.1063/5.0097112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Polymer crystallization has long been a fascinating problem and is still attracting many researchers. Most of the previous simulations are concentrated on clarifying the universal aspects of polymer crystallization using model linear polymers such as polyethylene. We are recently focusing on a nearly untouched but very interesting problem of chiral selecting crystallization in helical polymers. We previously proposed a stepwise approach using two kinds of helical polymers, simple "bare" helical polymers made of backbone atoms only such as polyoxymethylene (POM) and "general" helical polymers containing complicated side groups such as isotactic polypropylene (iPP). We have already reported on the crystallization in oligomeric POM-like helix but have observed only weak chiral selectivity during crystallization. In the present paper, we investigate the crystallization of sufficiently long POM-like polymer both from the isotropic melt and from the highly stretched melt. We find in both cases that the polymer shows a clear chiral selecting crystallization. Especially the observation of a single crystal growing from the isotropic melt is very illuminating. It shows that the crystal thickness and the crystal chirality is closely correlated; thicker crystals show definite chirality while thinner ones are mostly mixtures of the R- and the L- handed stems. The single crystal is found to have a marked lenticular shape, where the thinner growth front, since being made of the mixture, shows no chiral selectivity. Final chiral crystal is found to be completed through helix reversal processes within thicker regions.
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Affiliation(s)
- Takashi Yamamoto
- Department of Physics and Informatics, Yamaguchi University, Japan
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3
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Olkhov AA, Mastalygina EE, Ovchinnikov VA, Monakhova TV, Vetcher AA, Iordanskii AL. Thermo-Oxidative Destruction and Biodegradation of Nanomaterials from Composites of Poly(3-hydroxybutyrate) and Chitosan. Polymers (Basel) 2021; 13:polym13203528. [PMID: 34685287 PMCID: PMC8541602 DOI: 10.3390/polym13203528] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 09/28/2021] [Accepted: 10/07/2021] [Indexed: 12/24/2022] Open
Abstract
A complex of structure-sensitive methods of morphology analysis was applied to study film materials obtained from blends of poly(3-hydroxybutyrate) (PHB) and chitosan (CHT) by pouring from a solution, and nonwoven fibrous materials obtained by the method of electrospinning (ES). It was found that with the addition of CHT to PHB, a heterophase system with a nonequilibrium stressed structure at the interface was formed. This system, if undergone accelerated oxidation and hydrolysis, contributed to the intensification of the growth of microorganisms. On the other hand, the antimicrobial properties of CHT led to inhibition of the biodegradation process. Nonwoven nanofiber materials, since having a large specific surface area of contact with an aggressive agent, demonstrated an increased ability to be thermo-oxidative and for biological degradation in comparison with film materials.
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Affiliation(s)
- Anatoly A. Olkhov
- Scientific Laboratory “Advanced Composite Materials and Technologies”, Plekhanov Russian University of Economics, 36 Stremyanny Ln, 117997 Moscow, Russia; (A.A.O.); (E.E.M.); (V.A.O.)
- N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygin St., 119991 Moscow, Russia;
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 4 Kosygin St. 4, 119334 Moscow, Russia;
| | - Elena E. Mastalygina
- Scientific Laboratory “Advanced Composite Materials and Technologies”, Plekhanov Russian University of Economics, 36 Stremyanny Ln, 117997 Moscow, Russia; (A.A.O.); (E.E.M.); (V.A.O.)
- N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygin St., 119991 Moscow, Russia;
| | - Vasily A. Ovchinnikov
- Scientific Laboratory “Advanced Composite Materials and Technologies”, Plekhanov Russian University of Economics, 36 Stremyanny Ln, 117997 Moscow, Russia; (A.A.O.); (E.E.M.); (V.A.O.)
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 4 Kosygin St. 4, 119334 Moscow, Russia;
| | - Tatiana V. Monakhova
- N.M. Emanuel Institute of Biochemical Physics, Russian Academy of Sciences, 4 Kosygin St., 119991 Moscow, Russia;
| | - Alexandre A. Vetcher
- Institute of Biochemical Technology and Nanotechnology (IBTN), Peoples’ Friendship University of Russia (RUDN), 6 Miklukho-Maklaya St., 117198 Moscow, Russia
- Complementary and Integrative Health Clinic of Dr. Shishonin, 5 Yasnogorskaya St., 117588 Moscow, Russia
- Correspondence:
| | - Alexey L. Iordanskii
- N.N. Semenov Federal Research Center for Chemical Physics, Russian Academy of Sciences, 4 Kosygin St. 4, 119334 Moscow, Russia;
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Hall KW, Sirk TW, Percec S, Klein ML, Shinoda W. Divining the shape of nascent polymer crystal nuclei. J Chem Phys 2019; 151:144901. [PMID: 31615257 DOI: 10.1063/1.5123983] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
We demonstrate that nascent polymer crystals (i.e., nuclei) are anisotropic entities with neither spherical nor cylindrical geometry, in contrast to previous assumptions. In fact, cylindrical, spherical, and other high symmetry geometries are thermodynamically unfavorable. Moreover, postcritical transitions are necessary to achieve the lamellae that ultimately arise during the crystallization of semicrystalline polymers. We also highlight how inaccurate treatments of polymer nucleation can lead to substantial errors (e.g., orders of magnitude discrepancies in predicted nucleation rates). These insights are based on quantitative analysis of over four million crystal clusters from the crystallization of prototypical entangled polyethylene melts. New comprehensive bottom-up models are needed to capture polymer nucleation.
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Affiliation(s)
- Kyle Wm Hall
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Timothy W Sirk
- U.S. Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, Maryland 21005, USA
| | - Simona Percec
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Michael L Klein
- Department of Chemistry, Temple University, Philadelphia, Pennsylvania 19122, USA
| | - Wataru Shinoda
- Department of Materials Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan
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5
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Xiong J, Gong DP, Sun YM, Zhao XP. Effect of sulfur phase transition on polypropylene crystallization. POLYM-PLAST TECH MAT 2018. [DOI: 10.1080/03602559.2018.1552707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Affiliation(s)
- Jun Xiong
- College of Materials and Chemical Engineering, Hubei University of Technology, Wuhan, Hubei, China
- Hubei Province Key Laboratory of Green Light Industry Materials, Hubei University of Technology, Wuhan, Hubei, China
| | - De-Peng Gong
- College of Materials and Chemical Engineering, Hubei University of Technology, Wuhan, Hubei, China
- Hubei Province Key Laboratory of Green Light Industry Materials, Hubei University of Technology, Wuhan, Hubei, China
| | - Yi-Ming Sun
- College of Materials and Chemical Engineering, Hubei University of Technology, Wuhan, Hubei, China
- Hubei Province Key Laboratory of Green Light Industry Materials, Hubei University of Technology, Wuhan, Hubei, China
| | - Xi-Po Zhao
- College of Materials and Chemical Engineering, Hubei University of Technology, Wuhan, Hubei, China
- Hubei Province Key Laboratory of Green Light Industry Materials, Hubei University of Technology, Wuhan, Hubei, China
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7
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Luo C, Kröger M, Sommer JU. Entanglements and Crystallization of Concentrated Polymer Solutions: Molecular Dynamics Simulations. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b02124] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Chuanfu Luo
- Leibniz-Institut
für Polymerforschung Dresden e.V., Hohe Strasse 6, 01069 Dresden, Germany
- Max Planck Institute
of Colloids and Interfaces, Am Mühlenberg
1, 14476 Potsdam, Germany
| | - Martin Kröger
- Polymer
Physics, Department of Materials, ETH Zurich, CH-8093 Zurich, Switzerland
| | - Jens-Uwe Sommer
- Leibniz-Institut
für Polymerforschung Dresden e.V., Hohe Strasse 6, 01069 Dresden, Germany
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8
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Romanos NA, Theodorou DN. Melting Point and Solid–Liquid Coexistence Properties of α1 Isotactic Polypropylene as Functions of Its Molar Mass: A Molecular Dynamics Study. Macromolecules 2016. [DOI: 10.1021/acs.macromol.6b00819] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Nikolaos A. Romanos
- School of Chemical Engineering, Department of Materials Science & Engineering, National Technical University of Athens, 9 Heroon Polytechniou Street, Zografou Campus, 157 80 Athens, Greece
| | - Doros N. Theodorou
- School of Chemical Engineering, Department of Materials Science & Engineering, National Technical University of Athens, 9 Heroon Polytechniou Street, Zografou Campus, 157 80 Athens, Greece
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9
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Yamamoto T. Molecular Dynamics of Crystallization in a Helical Polymer Isotactic Polypropylene from the Oriented Amorphous State. Macromolecules 2014. [DOI: 10.1021/ma500307h] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Takashi Yamamoto
- Department of Physics and Informatics, Yamaguchi University, Yamaguchi 753-8512, Yamaguchi, Japan
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10
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Nonisothermal crystallization kinetics of PA6 and PA6/SEBS-g-MA blends. JOURNAL OF POLYMER RESEARCH 2012. [DOI: 10.1007/s10965-012-9926-1] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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11
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Yang H, Zhao XJ, Sun M. Induced crystallization of single-chain polyethylene on a graphite surface: molecular dynamics simulation. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2011; 84:011803. [PMID: 21867201 DOI: 10.1103/physreve.84.011803] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2010] [Revised: 01/26/2011] [Indexed: 05/31/2023]
Abstract
Molecular dynamics (MD) simulations have been carried out on the crystallization of single-chain polyethylene (PE) which was adsorbed on a graphite (001) surface on one side and exposed to vacuum on the other at different temperatures. The MD simulation data have been analyzed to provide information about the crystallization process of polymer adsorbed on the solid substrate. The isothermal crystallization of PE proceeds in two steps: (1) adsorption and (2) orientation. The results detail the radial density distribution function, ordered parameters, local bond-orientational order parameters, and the local properties displayed in layers of the polymer parallel to the graphite and vacuum interfaces. It was also shown that the film thickness affected the critical crystallization temperature of the adsorbed polymer on the substrate surface. Furthermore, the influence of the graphite surface area on the crystallization of PE is discussed by comparing the crystallinity evolution of PE on graphite with different coverage.
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Affiliation(s)
- Hua Yang
- College of Chemistry, Tianjin Key Laboratory of Structure and Performance for Functional Molecule, Tianjin Normal University, Tianjin 300387, People's Republic of China.
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12
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Luo C, Sommer JU. Growth Pathway and Precursor States in Single Lamellar Crystallization: MD Simulations. Macromolecules 2011. [DOI: 10.1021/ma102380m] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Chuanfu Luo
- Leibniz Institute of Polymer Research Dresden, Hohe Str 6, 01069 Dresden, Germany
| | - Jens-Uwe Sommer
- Leibniz Institute of Polymer Research Dresden, Hohe Str 6, 01069 Dresden, Germany
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13
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Yamamoto T. Molecular Dynamics of Reversible and Irreversible Melting in Chain-Folded Crystals of Short Polyethylene-like Polymer. Macromolecules 2010. [DOI: 10.1021/ma101777d] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Affiliation(s)
- Takashi Yamamoto
- Department of Physics and Informatics, Yamaguchi University, Yamaguchi 753-8512, Japan
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14
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Yamamoto T. Molecular dynamics simulations of polymer crystallization in highly supercooled melt: Primary nucleation and cold crystallization. J Chem Phys 2010; 133:034904. [DOI: 10.1063/1.3463393] [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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15
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Romanos NA, Theodorou DN. Crystallization and Melting Simulations of Oligomeric α1 Isotactic Polypropylene. Macromolecules 2010. [DOI: 10.1021/ma100677f] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Nikolaos A. Romanos
- School of Chemical Engineering, Department of Materials Science & Engineering, National Technical University of Athens, Heroon Polytechniou 9, Zografou Campus, 157 80 Athens, Greece
| | - Doros N. Theodorou
- School of Chemical Engineering, Department of Materials Science & Engineering, National Technical University of Athens, Heroon Polytechniou 9, Zografou Campus, 157 80 Athens, Greece
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16
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17
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Yamamoto T. Molecular dynamics simulations of steady-state crystal growth and homogeneous nucleation in polyethylene-like polymer. J Chem Phys 2008; 129:184903. [DOI: 10.1063/1.3009229] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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18
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Mao W, Kong B, Yang X, Nies E. Nascent crystallization of a growing chain on a catalyst surface: a nonequilibrium molecular dynamics simulation study. J Phys Chem B 2008; 112:6753-61. [PMID: 18461990 DOI: 10.1021/jp8002245] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The growing chain molecular dynamics (GCMD) simulation method, a new nonequilibrium molecular dynamics code, is proposed to simulate the polymer chain aggregation behavior during polymerization on a catalyst surface. We found that the growing chain crystallizes on the surface in two stages: the nucleation stage and the crystal growth stage. In the first part of the nucleation period, the short polymerizing chain first absorbs on the surface and can be in either an ordered or disordered structure. Still in the nucleation period, when the chain reaches a degree of polymerization, about 100 bonds, the chain folds into a stable nucleus on the substrate with 3-5 stems. In the crystal growth stage where the polymerization also proceeds, we observed a stem elongation process in combination with a chain folding process. In the stem elongation step, the number of stems in the nucleus remains constant, and all the stems expand together to a length of ca. 5-25 ns. In the subsequent chain folding step, the stem length decreases about 20 bonds within a period of ca. 0.1-0.5 ns. During chain growth, the elongation process and the folding process occur in an alternating and repeated fashion. The crystallization mechanism of the polymerizing chain was discussed.
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Affiliation(s)
- Wei Mao
- Beijing National Laboratory for Molecular Sciences, Joint Laboratory of Polymer Science and Materials, State Key Laboratory of Polymer Physics and Chemistry, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100080, China
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19
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Cheng S, Hu W, Ma Y, Yan S. Epitaxial polymer crystal growth influenced by partial melting of the fiber in the single-polymer composites. POLYMER 2007. [DOI: 10.1016/j.polymer.2007.05.030] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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20
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Yamamoto T. Molecular Dynamics Simulation of Polymer Crystallization from the Melt. J MACROMOL SCI B 2007. [DOI: 10.1081/mb-120021594] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Takashi Yamamoto
- a Department of Physics, Biology, and Informatics, Faculty of Science , Yamaguchi University , Yamaguchi, Japan
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21
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Balamurugan GP, Maiti SN. Nonisothermal crystallization kinetics of polyamide 6 and ethylene-co-butyl acrylate blends. J Appl Polym Sci 2007. [DOI: 10.1002/app.27377] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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22
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Yamamoto T. Crystallization of helical oligomers with chirality selection. I. A molecular dynamics simulation for bare helix. J Chem Phys 2006; 125:64902. [PMID: 16942307 DOI: 10.1063/1.2234475] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Helical polymers often exhibit pronounced chirality recognition during crystallization. By molecular dynamics simulation, we have already shown that the helical polymers crystallize with or without marked chirality selection depending on structural details of the polymer molecules. We have there classified the helical polymers into two categories: the bare helices made of only backbone atoms which show rather tolerant chirality selection, and the general helices with large side groups showing strict chirality recognition. Polymer crystallization is in general largely hampered and retarded by slow dynamics of the entangled chains, and therefore short helical oligomers are very suitable models for studying the chiral crystallization. We here report on molecular simulations of crystallization in the bare helical oligomer molecules by the use of Monte Carlo and molecular dynamics simulations. First we confirm the low temperature chiral crystal phase and the reversible order-disorder transition. We also observe frequent inversions of the helical sense, and the helix reversal defects propagating along the chains. Then we investigate crystallization from the melt into the chiral crystal phase. We find that the crystallization rate depends very sensitively on the degree of undercooling. The crystallization is found to be the first order transition that conforms well to the traditional picture of crystal growth in small molecules. Even when the crystallization directly into the chiral crystal phase is conducted, marked chirality selections are not observed at the early stage of crystallization; the chains adhere to the crystal surfaces selecting their helical senses rather at random resulting in racemic crystallites. The isothermal crystallization for a sufficiently long time, however, yields lamellar crystals composed of well-developed chiral domains, the growth of which seems to be accomplished through the transition back into the ordered chiral crystal phase.
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Affiliation(s)
- Takashi Yamamoto
- Department of Physics and Informatics, Yamaguchi University, Yamaguchi 753-8512, Japan.
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23
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Yang J, McCoy BJ, Madras G. Distribution kinetics of polymer crystallization and the Avrami equation. J Chem Phys 2006; 122:064901. [PMID: 15740402 DOI: 10.1063/1.1844373] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Cluster distribution kinetics is adopted to explore the kinetics of polymer crystallization. Population balance equations based on crystal size distribution and concentration of amorphous polymer segments are solved numerically and the related dynamic moment equations are also solved. The model accounts for heterogeneous or homogeneous nucleation and crystal growth. Homogeneous nucleation rates follow the classical surface-energy nucleation theory. Different mass dependences of growth and dissociation rate coefficients are proposed to investigate the fundamental features of nucleation and crystal growth. A comparison of moment solutions with numerical solutions examines the validity of the model. The proposed distribution kinetics model provides a different interpretation of the familiar Avrami equation.
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Affiliation(s)
- Jiao Yang
- Department of Chemical Engineering, Louisiana State University, Baton Rouge, Louisiana 70803, USA
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24
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Yamamoto T, Sawada K. Molecular-dynamics simulation of crystallization in helical polymers. J Chem Phys 2005; 123:234906. [PMID: 16392948 DOI: 10.1063/1.2137715] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The molecular mechanism of crystallization in helical polymers is a fascinating but very difficult subject of research. We here report our recent efforts toward better understanding of the crystallization in helical polymers by use of molecular-dynamics simulation. With straightforward approaches to the problem being quite difficult, we adopt a different strategy of categorizing the helical polymers into two distinct types: one type is a simple bare helix which is essentially made of backbone atomic groups only and has smoother molecular contours, and the other is a more general helix having large side groups that would considerably hamper molecular motion and crystallization. Both types of helical polymers are here constructed by use of the united atom model, but they show quite distinct crystallization behavior; the crystallization of the former-type polymer is rather fast, while that of the latter-type polymer is extremely slow. We find that the bare helix, when rapidly cooled in free three-dimensional space, freezes into partially ordered state with limited intramolecular and intermolecular orders, and that remarkable improvement of order and growth of an ordered chain-folded crystallite occurs by very long-time annealing of the partially ordered state around the apparent freezing temperature. We also study crystallization of the bare helix upon a growth surface; the crystallization in this case proceeds much faster through highly cooperative process of the intermolecular and the intramolecular degrees of freedom. On the other hand, crystallization of the realistic model of isotactic polypropylene (iPP) having pendant methylene groups is found to be extremely sluggish. By restricting the spatial dimension of the system thereby fully disentangling the chain, we observe that the molecule of iPP crystallizes very quickly onto the crystal substrate made of the same iPP chain. Quite remarkable is that the molecule of iPP strictly recognizes the helical sense of the substrate chain and efficiently selects its chirality during crystallization.
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Affiliation(s)
- Takashi Yamamoto
- Department of Physics, Biology and Informatics, Faculty of Science, Yamaguchi University, Yamaguchi 753-8512, Japan.
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25
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Hobbs JK, Vasilev C, Humphris AD. Real time observation of crystallization in polyethylene oxide with video rate atomic force microscopy. POLYMER 2005. [DOI: 10.1016/j.polymer.2005.08.042] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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26
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Yang J, McCoy BJ, Madras G. Temperature effects for isothermal polymer crystallization kinetics. J Chem Phys 2005; 122:244905. [PMID: 16035814 DOI: 10.1063/1.1924502] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
We adopt the cluster size distribution model to investigate the effect of temperature on homogeneous nucleation and crystal growth for isothermal polymer crystallization. The model includes the temperature effects of interfacial energy, nucleation rate, growth and dissociation rate coefficients, and equilibrium solubility. The time dependencies of polymer concentration, number and size of crystals, and crystallinity (in Avrami plots) are presented for different temperatures. The denucleation (Ostwald ripening effect) is also investigated by comparing moment and numerical solutions of the population balance equations. Agreement between the model results and temperature-sensitive experimental measurements for different polymer systems required strong temperature dependence for the crystal-melt interfacial energy.
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Affiliation(s)
- Jiao Yang
- Department of Chemical Engineering, Louisiana State University, Baton Rouge, 70803, USA
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27
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Daoulas KC, Harmandaris VA, Mavrantzas VG. Detailed Atomistic Simulation of a Polymer Melt/Solid Interface: Structure, Density, and Conformation of a Thin Film of Polyethylene Melt Adsorbed on Graphite. Macromolecules 2005. [DOI: 10.1021/ma050176r] [Citation(s) in RCA: 171] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Kostas Ch. Daoulas
- Department of Chemical Engineering, University of Patras, GR 26504, Patras, Greece, and Institute of Chemical Engineering and High-Temperature Chemical Processes (FORTH-ICE/HT), GR 26504, Patras, Greece
| | - Vagelis A. Harmandaris
- Department of Chemical Engineering, University of Patras, GR 26504, Patras, Greece, and Institute of Chemical Engineering and High-Temperature Chemical Processes (FORTH-ICE/HT), GR 26504, Patras, Greece
| | - Vlasis G. Mavrantzas
- Department of Chemical Engineering, University of Patras, GR 26504, Patras, Greece, and Institute of Chemical Engineering and High-Temperature Chemical Processes (FORTH-ICE/HT), GR 26504, Patras, Greece
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28
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Ungar G, Putra EGR, de Silva DSM, Shcherbina MA, Waddon AJ. The Effect of Self-Poisoning on Crystal Morphology and Growth Rates. ADVANCES IN POLYMER SCIENCE 2005. [DOI: 10.1007/b107232] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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29
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30
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Toda A. Kinetic barrier of pinning in polymer crystallization: Rate equation approach. J Chem Phys 2003. [DOI: 10.1063/1.1565998] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Lavine MS, Waheed N, Rutledge GC. Molecular dynamics simulation of orientation and crystallization of polyethylene during uniaxial extension. POLYMER 2003. [DOI: 10.1016/s0032-3861(03)00017-x] [Citation(s) in RCA: 152] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Yamamoto T. Molecular dynamics simulation of polymer ordering. II. Crystallization from the melt. J Chem Phys 2001. [DOI: 10.1063/1.1410377] [Citation(s) in RCA: 62] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Jang JH, Mattice WL. A Monte Carlo Simulation for the Effect of Compression on an Amorphous Polyethylene Melt in Very Thin Confined Geometry. Macromolecules 2000. [DOI: 10.1021/ma991605m] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Jee Hwan Jang
- Institute of Polymer Science, University of Akron, Akron, Ohio 44325-3909
| | - Wayne L. Mattice
- Institute of Polymer Science, University of Akron, Akron, Ohio 44325-3909
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Doye JPK, Frenkel D. Kinetic Monte Carlo simulations of the growth of polymer crystals. J Chem Phys 1999. [DOI: 10.1063/1.477992] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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