1
|
Wen YH, Wang CC, Cyue GS, Kuo RH, Hsu CH, Chang RY. Retrieving Equivalent Shear Viscosity for Molten Polymers from 3-D Nonisothermal Capillary Flow Simulation. Polymers (Basel) 2021; 13:polym13234094. [PMID: 34883598 PMCID: PMC8659291 DOI: 10.3390/polym13234094] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/17/2021] [Accepted: 11/22/2021] [Indexed: 11/16/2022] Open
Abstract
For highly viscous polymer melts, considerable fluid temperature rises produced by viscous heating can be a disturbing factor in viscosity measurements. By scrutinizing the experimental and simulated capillary pressure losses for polymeric liquids, we demonstrate the importance of applying a viscous heating correction to the shear viscosity, so as to correct for large errors introduced by the undesirable temperature rises. Specifically, on the basis of a theoretical derivation and 3-D nonisothermal flow simulation, an approach is developed for retrieving the equivalent shear viscosity in capillary rheometry, and we show that the shear viscosity can be evaluated by using the average fluid temperature at the wall, instead of the bulk temperature, as previously assumed. With the help of a viscous Cross model in analyzing the shear-dominated capillary flow, it is possible to extract the viscous heating contribution to capillary pressure loss, and the general validity of the methodology is assessed using the experiments on a series of thermoplastic melts, including polymers of amorphous, crystalline, and filler-reinforced types. The predictions of the viscous model based on the equivalent viscosity are found to be in good to excellent agreement with experimental pressure drops. For all the materials studied, a near material-independent scaling relation between the dimensionless temperature rise (Θ) and the Nahme number (Na) is found, Θ ~ Na0.72, from which the fluid temperature rise due to viscous heating as well as the resultant viscosity change can be predicted.
Collapse
|
2
|
Schramm S, Weiß D. Fluorescent heterocycles: Recent trends and new developments. ADVANCES IN HETEROCYCLIC CHEMISTRY 2019. [DOI: 10.1016/bs.aihch.2018.10.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
|
3
|
Battisti A, Ambrosetti M, Ruggeri G, Cappelli C, Pucci A. A 4,4'-bis(2-benzoxazolyl)stilbene luminescent probe: assessment of aggregate formation through photophysics experiments and quantum-chemical calculations. Phys Chem Chem Phys 2018; 20:26249-26258. [PMID: 30324198 DOI: 10.1039/c8cp04450c] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
A combination of experimental and quantum mechanical investigations is applied to the study of the optical features of 4,4'-bis(2-benzoxazolyl)stilbene (BBS) dissolved in solution or in a poly(l-lactic acid) (PLA) thermoplastic matrix at different concentrations. The experimental analyses allow the characterization of BBS solutions and dispersions in terms of absorption and emission features, along with the collection of some key parameters such as fluorescence quantum yield, anisotropy and lifetime, while the computational approach gives a detailed description of the photophysical behavior of BBS in the different environments. For the 10-5 M BBS solution, the fluorescence spectra show the expected peaks at 425 and 455 nm of the non-interacting BBS molecules with a single fluorescence lifetime of 0.85 ns without revealing any aggregation phenomena, prevented by the short lifetime and fast diffusion rate of the monomer. Moreover, the calculated spectra are in excellent agreement with the experiments, thus showing the reliability of the computational approach. In time-resolved emission experiments (TRES) on more concentrated solutions (10-4 M) and on BBS crystals, the presence of an excimer is revealed by the appearance of a broad peak around 540 nm, followed by the disappearance of the two main peaks at 460 nm on a time scale of about 10 ns. The computational analysis attributes this behavior to the formation of aggregates of different geometries. The BBS dispersions in PLA reveal the presence of different BBS architectures depending on the fluorophore content. Even at low concentrations, BBS is mainly dispersed as a monomer in the matrix, spheroid aggregates of about 800-900 nm in diameter are also present and the relevant fluorescence spectra arise from the combination of monomer and aggregate contributions. At higher concentrations, BBS starts forming crystals of a peculiar helicoidal shape, with a diameter of about 2 μm, variable length up to several hundreds of μm and emission spectra similar to those of isolated BBS crystals.
Collapse
Affiliation(s)
- Antonella Battisti
- NEST - Scuola Normale Superiore and Istituto Nanoscienze - CNR (CNR-NANO), Piazza San Silvestro 12, I-56127 Pisa, Italy. and M3-Village, Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali - INSTM, p.zza San Silvestro 12, I-56127 Pisa, Italy
| | - Matteo Ambrosetti
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy.
| | - Giacomo Ruggeri
- Dipartimento di Chimica e Chimica Industriale, Universitá di Pisa, Via Moruzzi 13, I-56124 Pisa, Italy.
| | - Chiara Cappelli
- Scuola Normale Superiore, Piazza dei Cavalieri 7, I-56126 Pisa, Italy.
| | - Andrea Pucci
- Dipartimento di Chimica e Chimica Industriale, Universitá di Pisa, Via Moruzzi 13, I-56124 Pisa, Italy.
| |
Collapse
|
4
|
Carayon C, Fery-Forgues S. 2-Phenylbenzoxazole derivatives: a family of robust emitters of solid-state fluorescence. Photochem Photobiol Sci 2017; 16:1020-1035. [DOI: 10.1039/c7pp00112f] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In addition to thermal, chemical and photochemical stability, the 2-phenylbenzoxazole fragment exhibits attractive emission properties in the solid state, thus leading to highly photoluminescent materials and sensors.
Collapse
Affiliation(s)
- Chantal Carayon
- SPCMIB
- UMR5068
- CNRS-Université de Toulouse III Paul Sabatier
- Toulouse
- France
| | | |
Collapse
|
5
|
Cassagnau P, Bounor-Legaré V, Fenouillot F. Reactive Processing of Thermoplastic Polymers: A Review of the Fundamental Aspects. INT POLYM PROC 2013. [DOI: 10.3139/217.2032] [Citation(s) in RCA: 83] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
The review is devoted to the fundamental aspects of the reactive processing of thermoplastic polymers. First of all, some reactive processing examples, including polymer grafting (vinyl silane, maleic anhydride) and/or functionalization, bulk polymerization (urethane, lactams, acrylate, ∊-capolactone), polyester modification and new copolymers synthesis, are presented. From a fundamental point of view, the review covers the state of the art in the domains of rheology (specifically modelling of rheo-kinetics), diffusion and mixing in highly viscous reactive or non reactive media. Finally, 1, 2 and 3-D simulation of the reactive extrusion process in twin-screw extruder is reported at the end of the review.
Collapse
Affiliation(s)
- P. Cassagnau
- Université de Lyon, Lyon, France, IML/LMPB UMR-CNRS #5223, Ingénierie des Matériaux Polymères: Laboratoire desMatériaux Polymères et Biomatériaux, Villeurbanne, France
| | - V. Bounor-Legaré
- Université de Lyon, Lyon, France, IML/LMPB UMR-CNRS #5223, Ingénierie des Matériaux Polymères: Laboratoire desMatériaux Polymères et Biomatériaux, Villeurbanne, France
| | - F. Fenouillot
- Ingénierie des Matériaux Polymères: Laboratoire des Matériaux Macromoléculaires, IMP/LMM UMR-CNRS #5223, INSA-Lyon, 69621 Villeurbanne cedex – France
| |
Collapse
|
6
|
Fourati MA, Skene WG, Bazuin CG, Prud’homme RE. Photophysical and Electrochemical Investigations of the Fluorescent Probe, 4,4′-Bis(2-benzoxazolyl)stilbene. J Phys Chem A 2013; 117:836-44. [DOI: 10.1021/jp312598c] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. Amine Fourati
- Département
de Chimie, Université de
Montréal, CP 6128, Succ. Centre-Ville, Montréal, Québec,
Canada, H3C 3J7
| | - W. G. Skene
- Département
de Chimie, Université de
Montréal, CP 6128, Succ. Centre-Ville, Montréal, Québec,
Canada, H3C 3J7
| | - C. Géraldine Bazuin
- Département
de Chimie, Université de
Montréal, CP 6128, Succ. Centre-Ville, Montréal, Québec,
Canada, H3C 3J7
| | - Robert E. Prud’homme
- Département
de Chimie, Université de
Montréal, CP 6128, Succ. Centre-Ville, Montréal, Québec,
Canada, H3C 3J7
| |
Collapse
|
7
|
Fourati MA, Maris T, Skene WG, Bazuin CG, Prud’homme RE. Photophysical, Electrochemical and Crystallographic Investigations of the Fluorophore 2,5-Bis(5-tert-butyl-benzoxazol-2-yl)thiophene. J Phys Chem B 2011; 115:12362-9. [DOI: 10.1021/jp207136k] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- M. Amine Fourati
- Département de Chimie, Centre de recherche sur les matériaux auto-assemblés (CRMAA/CSACS), Université de Montréal, CP 6128, Succ. Centre-Ville, Montréal, Québec, Canada, H3C 3J7
| | - Thierry Maris
- Département de Chimie, Centre de recherche sur les matériaux auto-assemblés (CRMAA/CSACS), Université de Montréal, CP 6128, Succ. Centre-Ville, Montréal, Québec, Canada, H3C 3J7
| | - W. G. Skene
- Département de Chimie, Centre de recherche sur les matériaux auto-assemblés (CRMAA/CSACS), Université de Montréal, CP 6128, Succ. Centre-Ville, Montréal, Québec, Canada, H3C 3J7
| | - C. Géraldine Bazuin
- Département de Chimie, Centre de recherche sur les matériaux auto-assemblés (CRMAA/CSACS), Université de Montréal, CP 6128, Succ. Centre-Ville, Montréal, Québec, Canada, H3C 3J7
| | - Robert E. Prud’homme
- Département de Chimie, Centre de recherche sur les matériaux auto-assemblés (CRMAA/CSACS), Université de Montréal, CP 6128, Succ. Centre-Ville, Montréal, Québec, Canada, H3C 3J7
| |
Collapse
|
8
|
Paeng K, Lee HN, Swallen SF, Ediger MD. Temperature-ramping measurement of dye reorientation to probe molecular motion in polymer glasses. J Chem Phys 2011; 134:024901. [DOI: 10.1063/1.3507255] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- Keewook Paeng
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Hau-Nan Lee
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - Stephen F. Swallen
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| | - M. D. Ediger
- Department of Chemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706, USA
| |
Collapse
|
9
|
Fourati MA, Maris T, Bazuin CG, Prud'homme RE. (E)-4,4′-Bis(1,3-benzoxazol-2-yl)stilbene at 150 and 375 K. Acta Crystallogr C 2009; 66:o11-4. [DOI: 10.1107/s0108270109050379] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2009] [Accepted: 11/23/2009] [Indexed: 11/10/2022] Open
|
10
|
Kelly AL, Gough T, Whiteside BR, Coates PD. High shear strain rate rheometry of polymer melts. J Appl Polym Sci 2009. [DOI: 10.1002/app.30552] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
11
|
Li J, Sun Z, Tatibouët J, Jen CK. An in-process ultrasonic approach to investigating the relaxation of orientation and disorientation of polymer melts. POLYM ENG SCI 2008. [DOI: 10.1002/pen.21023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
12
|
Pucci A, Di Cuia F, Signori F, Ruggeri G. Bis(benzoxazolyl)stilbene excimers as temperature and deformation sensors for biodegradable poly(1,4-butylene succinate) films. ACTA ACUST UNITED AC 2007. [DOI: 10.1039/b612033d] [Citation(s) in RCA: 175] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
13
|
Pucci A, Bertoldo M, Bronco S. Luminescent Bis(benzoxazolyl)stilbene as a Molecular Probe for Poly(propylene) Film Deformation. Macromol Rapid Commun 2005. [DOI: 10.1002/marc.200500227] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|