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Billon N, Castellani R, Bouvard JL, Rival G. Viscoelastic Properties of Polypropylene during Crystallization and Melting: Experimental and Phenomenological Modeling. Polymers (Basel) 2023; 15:3846. [PMID: 37765698 PMCID: PMC10534810 DOI: 10.3390/polym15183846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 09/01/2023] [Accepted: 09/03/2023] [Indexed: 09/29/2023] Open
Abstract
This paper deals with the viscoelastic behavior during crystallization and melting of semicrystalline polymers, with the aim of later modeling the residual stresses after processing in cases where crystallization occurs in quasi-static conditions (in additive manufacturing for example). Despite an abundant literature on polymer crystallization, the current state of scientific knowledge does not yet allow ab initio modeling. Therefore, an alternative and pragmatic way has been explored to propose a first approximation of the impact of crystallization and melting on the storage and loss moduli during crystallization-melting-crystallization cycles. An experimental approach, combining DSC, optical microscopy and oscillatory shear rheology, was used to define macroscopic parameters related to the microstructure. These parameters have been integrated into a phenomenological model. Isothermal measurements were used to describe the general framework, and crystallization at a constant cooling rate was used to evaluate the feasibility of a general approach. It can be concluded that relying solely on the crystalline fraction is inadequate to model the rheology. Instead, accounting for the microstructure at the spherulitic level could be more useful. Additionally, the results obtained from the experiments help to enhance our understanding of the correlations between crystallization kinetics and its mechanical effects.
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Affiliation(s)
- Noëlle Billon
- Mines Paris, PSL University, Centre for Material Forming (CEMEF), UMR CNRS 7635, 06904 Sophia Antipolis, France; (R.C.); (J.-L.B.); (G.R.)
| | - Romain Castellani
- Mines Paris, PSL University, Centre for Material Forming (CEMEF), UMR CNRS 7635, 06904 Sophia Antipolis, France; (R.C.); (J.-L.B.); (G.R.)
| | - Jean-Luc Bouvard
- Mines Paris, PSL University, Centre for Material Forming (CEMEF), UMR CNRS 7635, 06904 Sophia Antipolis, France; (R.C.); (J.-L.B.); (G.R.)
| | - Guilhem Rival
- Mines Paris, PSL University, Centre for Material Forming (CEMEF), UMR CNRS 7635, 06904 Sophia Antipolis, France; (R.C.); (J.-L.B.); (G.R.)
- Lyon University, INSA-Lyon, LGEF, EA682, 69621 Villeurbanne, France
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Boyer SAE, Haudin J, Song V, Bourassier V, Navard P, Barron C. Transcrystallinity in maize tissues/polypropylene composites: First focus of the heterogeneous nucleation and growth stages versus tissue type. POLYMER CRYSTALLIZATION 2021. [DOI: 10.1002/pcr2.10155] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Séverine A. E. Boyer
- Mines ParisTech, PSL‐Research University, CEMEF‐Centre de Mise en Forme des Matériaux (Member of the European Polysaccharide Network of Excellence (EPNOE), www.epnoe.eu), UMR CNRS 7635 CS 10207, Rue Claude Daunesse, 06904,Sophia Antipolis Cedex France
| | - Jean‐Marc Haudin
- Mines ParisTech, PSL‐Research University, CEMEF‐Centre de Mise en Forme des Matériaux (Member of the European Polysaccharide Network of Excellence (EPNOE), www.epnoe.eu), UMR CNRS 7635 CS 10207, Rue Claude Daunesse, 06904,Sophia Antipolis Cedex France
| | - Vivian Song
- Mines ParisTech, PSL‐Research University, CEMEF‐Centre de Mise en Forme des Matériaux (Member of the European Polysaccharide Network of Excellence (EPNOE), www.epnoe.eu), UMR CNRS 7635 CS 10207, Rue Claude Daunesse, 06904,Sophia Antipolis Cedex France
| | - Vincent Bourassier
- Mines ParisTech, PSL‐Research University, CEMEF‐Centre de Mise en Forme des Matériaux (Member of the European Polysaccharide Network of Excellence (EPNOE), www.epnoe.eu), UMR CNRS 7635 CS 10207, Rue Claude Daunesse, 06904,Sophia Antipolis Cedex France
| | - Patrick Navard
- Mines ParisTech, PSL‐Research University, CEMEF‐Centre de Mise en Forme des Matériaux (Member of the European Polysaccharide Network of Excellence (EPNOE), www.epnoe.eu), UMR CNRS 7635 CS 10207, Rue Claude Daunesse, 06904,Sophia Antipolis Cedex France
| | - Cécile Barron
- IATE, University Montpellier, Cirad, INRAE, Institut Agro Montpellier France
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Kotula AP, Migler KB. Percolation Implications in the Rheology of Polymer Crystallization. POLYMER CRYSTALLIZATION 2021; 4:10.1002/pcr2.10162. [PMID: 34124594 PMCID: PMC8193685 DOI: 10.1002/pcr2.10162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 10/14/2020] [Indexed: 11/06/2022]
Abstract
The rheology of polymer crystallization is an old problem that often defies explanation due to the complex interrelationships between crystallization and flow properties. Although separate measurements of rheology and crystallinity can give some information on their relationship, it is only through simultaneous measurements that ideas on the rheology of polymer crystallization can be tested and developed. This Perspective details recent experimental developments in simultaneous crystallinity and rheology measurements as well as continuum modeling efforts for the case of quiescent and isothermal crystallization. Experimental results reveal that the rheology is dominated initially by growth of individual spherulites that evolve into spherulitic superstructures that eventually span the measurement geometry. A generalized effective medium model based on this concept of percolation can explain both the growth of the viscoelastic modulus during crystallization and the changes in the relaxation spectrum of the crystallizing polymer, including a critical gel response at percolation. The success of the combined measurement techniques and percolation concepts motivate research to extend the semicrystalline polymer materials space where these methods are applied as well as further develop novel techniques to gain additional insight into the evolution of structure and relaxation dynamics during crystallization.
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Affiliation(s)
- Anthony P. Kotula
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899
| | - Kalman B. Migler
- Materials Science and Engineering Division, National Institute of Standards and Technology, Gaithersburg, MD 20899
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Minale M, Carotenuto C, Paduano LP, Grassia L. Nonisothermal Crystallization Kinetics of an Ethylene‐Vinyl‐Acetate: I Calorimetry Versus Rheology. POLYM ENG SCI 2019. [DOI: 10.1002/pen.25248] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Affiliation(s)
- Mario Minale
- Department of EngineeringUniversity of Campania “Luigi Vanvitelli” 81031 Aversa Caserta Italy
| | - Claudia Carotenuto
- Department of EngineeringUniversity of Campania “Luigi Vanvitelli” 81031 Aversa Caserta Italy
| | - Liana P. Paduano
- Department of EngineeringUniversity of Campania “Luigi Vanvitelli” 81031 Aversa Caserta Italy
| | - Luigi Grassia
- Department of EngineeringUniversity of Campania “Luigi Vanvitelli” 81031 Aversa Caserta Italy
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Drzeżdżon J, Jacewicz D, Sielicka A, Chmurzyński L. Characterization of polymers based on differential scanning calorimetry based techniques. Trends Analyt Chem 2019. [DOI: 10.1016/j.trac.2018.10.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Billon N, Giraudeau J, Bouvard JL, Robert G. Mechanical Behavior-Microstructure Relationships in Injection-Molded Polyamide 66. Polymers (Basel) 2018; 10:polym10101047. [PMID: 30960972 PMCID: PMC6403566 DOI: 10.3390/polym10101047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2018] [Revised: 09/10/2018] [Accepted: 09/17/2018] [Indexed: 11/18/2022] Open
Abstract
Clear relationships between the semi-crystalline microstructure of injection molding polymers and their mechanical behavior are not yet totally established for all polymers. Part of this relative lack of understanding is because an unambiguous scientific approach is difficult to build up. The processing of samples promotes a microstructure which is not uniform and can be described in various ways on different scales. This introduces uncertainty in the correlations. Most completed studies were conducted on polyolefin, which exhibits an evolution of microstructure that is quite easy to observe and to correlate to mechanical properties. This paper intends to illustrate a more diffuse case. To achieve this, combined characterizations along the flow path and throughout the thickness of a plaque as well as characterizations of the local microstructure and tensile behavior of polyamide 66 are described. The microstructure was explored in terms of skin-core structure, spherulites sizes, crystallinity ratio and lamellae organization. Mechanical properties were addressed with non-monotonic tests with the use of DIC (Digital Image Correlation) to assess true behavior. The effect of humidity is also accounted for. It is demonstrated that small changes in lamellae or interlamellar amorphous phase are likely to be responsible for non-uniform mechanical properties, whereas more macroscopic levels (skin core structure, spherulites level of crystallinity ratio) appeared to be irrelevant levels of description. Consequently, the usual simplified analyses based on optical microscopy and differential scanning calorimetry (DSC) can be inefficient in improving knowledge in that field.
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Affiliation(s)
- Noëlle Billon
- MINES ParisTech, PSL Research University, CEMEF, CNRS UMR 7635, CS 10207, CEDEX, 06904 Sophia Antipolis, France.
| | - Joan Giraudeau
- MINES ParisTech, PSL Research University, CEMEF, CNRS UMR 7635, CS 10207, CEDEX, 06904 Sophia Antipolis, France.
| | - Jean Luc Bouvard
- MINES ParisTech, PSL Research University, CEMEF, CNRS UMR 7635, CS 10207, CEDEX, 06904 Sophia Antipolis, France.
| | - Gilles Robert
- Solvay Engineering Plastics, Technyl Innovation Center, Avenue Ramboz-BP64, 69192 Saint Fons, France.
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Hondros V, Vincent M, Freire L, Boyer SAE, Haudin JM, Royer V, François G, Ville L. Analysis of the No-Flow Criterion Based on Accurate Crystallization Data for the Simulation of Injection Molding of Semi-Crystalline Thermoplastics. INT POLYM PROC 2018. [DOI: 10.3139/217.3593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
It is well known in practice that the shape and dimensions of injected parts are highly dependent on the packing-holding stage. A major problem in semi-crystalline polymers is the prediction of the solidified layer, whose thickness has an important effect on shrinkage and warpage. We propose a pragmatic approach based on the concept of no-flow temperature. This temperature should be related to crystallization temperature, but the choice is not easy because it depends on cooling rate and pressure which are functions of time and position. The objective of the work is to evaluate the sensitivity of an injection molding computation to the no-flow temperature and to evaluate the relevance of its choice. The crystallization temperature of an isotactic polypropylene is determined as a function of cooling rate and pressure in laboratory experiments. The pressure dependence is measured using the original Cristapress cell. As a case study, we simulate the filling and post-filling of a plate mold using Rem3D, a 3D code for injection molding. Three no-flow temperatures and two sets of parameters for temperature dependence of viscosity are tested. Their respective influences on the pressure evolution are shown, and the crystallization temperature calculated a posteriori using the experimental material data is compared to the “arbitrary” no-flow temperature.
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Affiliation(s)
- V. Hondros
- MINES ParisTech , PSL Research University, CEMEF, CNRS, Sophia Antipolis , France
| | - M. Vincent
- MINES ParisTech , PSL Research University, CEMEF, CNRS, Sophia Antipolis , France
| | - L. Freire
- MINES ParisTech , PSL Research University, CEMEF, CNRS, Sophia Antipolis , France
| | - S. A. E. Boyer
- MINES ParisTech , PSL Research University, CEMEF, CNRS, Sophia Antipolis , France
| | - J.-M. Haudin
- MINES ParisTech , PSL Research University, CEMEF, CNRS, Sophia Antipolis , France
| | - V. Royer
- Transvalor S. A. , Sophia Antipolis , France
| | - G. François
- Transvalor S. A. , Sophia Antipolis , France
| | - L. Ville
- Transvalor S. A. , Sophia Antipolis , France
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