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Liparoti S, Sofia D, Romano A, Marra F, Pantani R. Fused Filament Deposition of PLA: The Role of Interlayer Adhesion in the Mechanical Performances. Polymers (Basel) 2021; 13:399. [PMID: 33513767 PMCID: PMC7865617 DOI: 10.3390/polym13030399] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 01/22/2021] [Accepted: 01/23/2021] [Indexed: 11/21/2022] Open
Abstract
A set of criteria to enhance mechanical performances of standard specimens (Type V, ANSI D368) made of polylactic acid (PLA) were proposed. Fused PLA deposition was conducted with nozzle temperature ranging from 180 to 230 °C and deposition plate temperature ranging from 70 to 110 °C. Optical microscopy, elastic modulus analysis and density measurement allowed emphasizing the effect of temperature field, also measured during the process, on the morphology and the mechanical characteristics of the specimen. Atomic force microscopy revealed a morphology typical of amorphous samples with globular structures. Poor interlayer adhesion was detected in the part of the specimen located at larger distance from the deposition plate, showing an elastic modulus lower than those measured in the central part (220 MPa vs. 500 MPa). The specimen crystallinity degree was below 3%. The molecular weight between entanglements was adopted as a measure of the interlayer molecular diffusion. A successful diffusion and re-entanglement of the polymer melt at the interface was the key to improving mechanical performance. A mathematical model describing the transient heat transfer during the fused PLA deposition and accounting for solidification and the nonisothermal crystallization kinetics was introduced. Simulated temperature evolutions were consistent with the experimental ones. They were related to the mechanical performances, the morphology, and the molecular weight between entanglements of the parts.
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Affiliation(s)
| | | | | | - Francesco Marra
- Department of Industrial Engineering, University of Salerno, Via Giovanni Paolo II, 132, 84084 Fiscian, SA, Italy; (S.L.); (D.S.); (A.R.); (R.P.)
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Ramos J, Vega J, Martínez-Salazar J. Predicting experimental results for polyethylene by computer simulation. Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2017.12.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Padding JT, Briels WJ. Systematic coarse-graining of the dynamics of entangled polymer melts: the road from chemistry to rheology. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2011; 23:233101. [PMID: 21613700 DOI: 10.1088/0953-8984/23/23/233101] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
For optimal processing and design of entangled polymeric materials it is important to establish a rigorous link between the detailed molecular composition of the polymer and the viscoelastic properties of the macroscopic melt. We review current and past computer simulation techniques and critically assess their ability to provide such a link between chemistry and rheology. We distinguish between two classes of coarse-graining levels, which we term coarse-grained molecular dynamics (CGMD) and coarse-grained stochastic dynamics (CGSD). In CGMD the coarse-grained beads are still relatively hard, thus automatically preventing bond crossing. This also implies an upper limit on the number of atoms that can be lumped together (up to five backbone carbon atoms) and therefore on the longest chain lengths that can be studied. To reach a higher degree of coarse-graining, in CGSD many more atoms are lumped together (more than ten backbone carbon atoms), leading to relatively soft beads. In that case friction and stochastic forces dominate the interactions, and action must be undertaken to prevent bond crossing. We also review alternative methods that make use of the tube model of polymer dynamics, by obtaining the entanglement characteristics through a primitive path analysis and by simulation of a primitive chain network. We finally review super-coarse-grained methods in which an entire polymer is represented by a single particle, and comment on ways to include memory effects and transient forces.
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Affiliation(s)
- J T Padding
- Institut de la Matière Condensée et des Nanosciences, Université Catholique de Louvain, Croix du Sud 1, B-1348 Louvain-la-Neuve, Belgium.
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Lahmar F, Tzoumanekas C, Theodorou DN, Rousseau B. Onset of Entanglements Revisited. Dynamical Analysis. Macromolecules 2009. [DOI: 10.1021/ma9011329] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- F. Lahmar
- Laboratoire de Chimie Physique, Université Paris-Sud 11, UMR 8000 CNRS, Orsay, France
| | - C. Tzoumanekas
- National Technical University of Athens, School of Chemical Engineering, Zografou Campus, GR-15780 Athens, Greece
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - D. N. Theodorou
- National Technical University of Athens, School of Chemical Engineering, Zografou Campus, GR-15780 Athens, Greece
- Dutch Polymer Institute (DPI), P.O. Box 902, 5600 AX Eindhoven, The Netherlands
| | - B. Rousseau
- Laboratoire de Chimie Physique, Université Paris-Sud 11, UMR 8000 CNRS, Orsay, France
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Lee WB, Kremer K. Entangled Polymer Melts: Relation between Plateau Modulus and Stress Autocorrelation Function. Macromolecules 2009. [DOI: 10.1021/ma9008498] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Won Bo Lee
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
| | - Kurt Kremer
- Max Planck Institute for Polymer Research, Ackermannweg 10, 55128 Mainz, Germany
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Padding JT, Boek ES, Briels WJ. Dynamics and rheology of wormlike micelles emerging from particulate computer simulations. J Chem Phys 2008; 129:074903. [DOI: 10.1063/1.2970934] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Kindt P, Briels WJ. A single particle model to simulate the dynamics of entangled polymer melts. J Chem Phys 2007; 127:134901. [DOI: 10.1063/1.2780151] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Evaluation of different methods for the determination of the plateau modulus and the entanglement molecular weight. POLYMER 2006. [DOI: 10.1016/j.polymer.2006.04.054] [Citation(s) in RCA: 253] [Impact Index Per Article: 14.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Blanchard A, Graham RS, Heinrich M, Pyckhout-Hintzen W, Rciher D, Likhtman AE, McLeish TCB, Read DJ, Straube E, Kohlbrecher J. Small angle neutron scattering observation of chain retraction after a large step deformation. PHYSICAL REVIEW LETTERS 2005; 95:166001. [PMID: 16281325 DOI: 10.1103/physrevlett.95.166001] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The process of retraction in entangled linear chains after a fast nonlinear stretch was detected from time-resolved but quenched small angle neutron scattering (SANS) experiments on long, well-entangled polyisoprene chains. The statically obtained SANS data cover the relevant time regime for retraction, and they provide a direct, microscopic verification of this nonlinear process as predicted by the tube model. Clear, quantitative agreement is found with recent theories of contour length fluctuations and convective constraint release, using parameters obtained mainly from linear rheology. The theory captures the full range of scattering vectors once the crossover to fluctuations on length scales below the tube diameter is accounted for.
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Affiliation(s)
- A Blanchard
- Jülich, Institut für Festkörperforschung, Germany
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León S, van der Vegt N, Delle Site L, Kremer K. Bisphenol A Polycarbonate: Entanglement Analysis from Coarse-Grained MD Simulations. Macromolecules 2005. [DOI: 10.1021/ma050943m] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S. León
- Max-Planck-Institute for Polymer Research, P.O. Box 3148, D-55021 Mainz, Germany, and Departamento de Ingeniería Química, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, E-28006 Madrid, Spain
| | - N. van der Vegt
- Max-Planck-Institute for Polymer Research, P.O. Box 3148, D-55021 Mainz, Germany, and Departamento de Ingeniería Química, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, E-28006 Madrid, Spain
| | - L. Delle Site
- Max-Planck-Institute for Polymer Research, P.O. Box 3148, D-55021 Mainz, Germany, and Departamento de Ingeniería Química, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, E-28006 Madrid, Spain
| | - K. Kremer
- Max-Planck-Institute for Polymer Research, P.O. Box 3148, D-55021 Mainz, Germany, and Departamento de Ingeniería Química, Universidad Politécnica de Madrid, José Gutiérrez Abascal 2, E-28006 Madrid, Spain
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Likhtman AE. Single-Chain Slip-Link Model of Entangled Polymers: Simultaneous Description of Neutron Spin−Echo, Rheology, and Diffusion. Macromolecules 2005. [DOI: 10.1021/ma050399h] [Citation(s) in RCA: 232] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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