Appropriate Boundary Conditions in the Flow of Molten Polymers
-
S. G. Hatzikiriakos
Abstract
There is considerable experimental evidence that the classical no-slip boundary condition of fluid mechanics is not always a valid assumption for the flow of high molecular weight molten polymers. In fact, molten polymers slip at solid surfaces when the wall shear stress exceeds a critical value. Moreover, there exists a second critical wall shear stress value at which a transition from a weak to a strong slip takes place. The later corresponds to the case of an almost plug flow and it is accompanied by pressure oscillations in the case of capillary flow generated by a constant-speed piston-driven capillary rheometer. The two modes of slip (weak and strong) are due to flow-induced chain detachment/desorption directly from the polymer/wall interface and to chain disentanglement of the polymer chains in the bulk from a monolayer of polymer chains adsorbed at the interface. In this work, the two physical mechanisms of slip are discussed and validated on the basis of suitably analyzed experimental data. Based on these two modes of slip, the slip phenomena observed during the capillary flow of polymers (mainly polyethylenes) are explained including the absence of pressure oscillations in the capillary flow of branched polyethylenes.
References
Anastasiadis, S., Hatzikiriakos, S. G., “The Work of Adhesion of Polymer/Wall Interfaces and Its Association wth the Onset of Slip”, J. Rheol., 42, 795–812(1998), DOI: 10.1122/1.550909Suche in Google Scholar
Archer, L. A., “Chapter 4 Wall Slip: Measurement and Modelling Issues” in Polymer Processing Instabilities, Hatzikiriakos, S. G., and MiglerK. B., (Eds.), Marcel Dekker, New York, 73–120(2005)Suche in Google Scholar
Bagley, E. B., “End Corrections In the Capillary Flow of Polyethylene”, J. Appl. Phys., 28, 193–209(1957), DOI: 10.1063/1.1722814Suche in Google Scholar
Bergem, N., “Visualization Studies of Polymer Melt Flow Anomalies in Extrusion”, VIIth Int. Congr. Rheol., Swedish Soc. Rheol., 50–55(1976)Suche in Google Scholar
Bick, D. K., McLeish, T. C. B., “Topological Contributions to Nonlinear Elasticity In Branched Polymers,” Phy. Rev. Lett., 76, 2587–2590(1996), PMid:10060737, DOI: 10.1103/PhysRevLett.76.2587Suche in Google Scholar
deGennes, P. G., “Reptation of a Polymer Chain In Presence of Fixed Obstacles”, J. Chem Physics, 55, 572–579(1971), DOI: 10.1063/1.1675789Suche in Google Scholar
Brochard-Wyart, F., deGennes, P. G., “Shear-dependent Slippage at a Polymer/Solid Interface”, Langmuir, 8, 3033–3037(1992), DOI: 10.1021/la00048a030Suche in Google Scholar
Delgadillo-Velázquez, O., Hatzikiriakos, S. G., “Processability of LLDPE/LDPE Blends: Capillary Extrusion Studies”, Polym. Eng. Sci., 47, 1317–1326(2007)10.1002/pen.20811Suche in Google Scholar
Delgadillo-Velázquez, O., Hatzikiriakos, S. G., “Capillary Extrusion Studies of LLDPE/LDPE Blends: Effects of Manufacturing Technology of LLDPE and Long Chain Branching”, Int. Polym. Proc., 23, 385–394(2008), DOI: 10.3139/217.2155Suche in Google Scholar
Drda, P. A., Wang, S.-Q., “Stick-slip Transition at Polymer Melt/Solid Interfaces”, Phys. Rev. Lett., 75, 2698–2701(1995), PMid:10059382, DOI: 10.1103/PhysRevLett.75.2698Suche in Google Scholar
El Kissi, N., Piau, J. P., “The Different Capillary Flow Regimes of Entangled Polydimethylsiloxane Polymers: Macroscopic Slip at the Wall, Hysteresis and Cork Flow”, J. Non-Newtonian Fluid Mech., 37, 55–94(1990), DOI: 10.1016/0377-0257(90)80004-JSuche in Google Scholar
Hatzikiriakos, S. G., Dealy, J. M., “Wall Slip of Molten High Density Polyethylene I. Sliding Plate Rheometer Studies”, J. Rheol., 35, 497–523(1991), DOI: 10.1122/1.550178Suche in Google Scholar
Hatzikiriakos, S. G., Dealy, J. M., “Wall Slip of Molten High Density Polyethylene. II. Capillary Rheometer Studies”, J. Rheol., 36, 703–741(1992a), DOI: 10.1122/1.550313Suche in Google Scholar
Hatzikiriakos, S. G., Dealy, J. M., “Role of Slip And Fracture In The Oscillating Flow Of HDPE In A Capillary”, J. Rheol., 36, 845–884(1992b), DOI: 10.1122/1.550320Suche in Google Scholar
Hatzikiriakos, S. G., et al., “Effect of Interfacial Conditions on Wall Slip and Sharkskin Melt Fracure of HDPE”, Inter. Polym. Proc., 9, 330–335(1993)Suche in Google Scholar
Hatzikiriakos, S. G., “A Slip Model for Linear Polymers Based on Adhesive Failure”, Inter. Polym. Proc., 9, 135–142(1993)Suche in Google Scholar
Hatzikiriakos, S. G., Kalogerakis, N., “A Dynamic Slip Velocity Model for Molten Polymers Based on a Network Kinetic Theory”, Rheol. Acta, 33, 38–47(1994), DOI: 10.1007/BF00453462Suche in Google Scholar
Hatzikiriakos, S. G., et al., “Interfacial Phenomena in the Capillary Extrusion of Metallocene Polyethylenes”, J. Rheol., 41, 1299–1316(1997), DOI: 10.1122/1.550836Suche in Google Scholar
Israelachvili, J. N.: Intermolecular and Surface Forces, Academic Press, New York(1985)Suche in Google Scholar
Kalika, D., Denn, M. M., “Wall Slip and Extrudate Distortion in Linear Low Density Polyethylene”, J. Rheol., 31, 815–834(1987), DOI: 10.1122/1.549942Suche in Google Scholar
Larrazabal, H. J., et al., “On The Relationship between the Work of Adhesion and the Critical Shear Stress for the Onset of Flow Instabilities”, Rheol. Acta, 45, 705–715(2006a), DOI: 10.1007/s00397-005-0028-4Suche in Google Scholar
LarrazabalH.J., et al., “Effect of the Chemical and Morphological Conditions of the Die Wall on the Extrusion of Linear Polyolefins”, Inter. Polym. Proc., 21, 132–140(2006b)10.3139/217.0067Suche in Google Scholar
Lim, F. J., Schowalter, W. R., “Wall Slip of Narrow Molecular Weight Distribution Polybutadienes”, J. Rheol., 33, 1359–1382(1989), DOI: 10.1122/1.550073Suche in Google Scholar
Migler, K. B., et al., “Slip Transition of a Polymer Melt under Shear Stress”, Phys. Rev. Lett., 70, 287–290(1993), PMid:10054074, DOI: 10.1103/PhysRevLett.70.287Suche in Google Scholar PubMed
Ramamurthy, A. V., “Wall Slip in Viscous Fluids and Influence of Materials of Construction”, J. Rheol., 30, 337–357(1986), DOI: 10.1122/1.549852Suche in Google Scholar
Vinogradov, G. V., et al., “Viscoelastic Properties and Flow of Narrow Polybutadienes and Polyisoprenes”, J. Polym. Sci. Part A-2, 10, 1061–1075(1972)10.1002/pol.1972.160100609Suche in Google Scholar
Wang, S.-Q., Drda, P. A., “Superfluid-like Stick-slip Transition in Capillary Flow of Linear Polyethylene Melts. 1. General Features”, Macromolecules, 29, 2627–2633(1996a), DOI: 10.1021/ma950898qSuche in Google Scholar
Wang, S.-Q., Drda, P. A., “Stick-slip Transition in Capillary Flow of Polyethylene. 2. Molecular Weight Dependence and Low Temperature Anomaly”, Macromolecules, 29, 4115–4119(1996b), DOI: 10.1021/ma951512eSuche in Google Scholar
Wise, G. M., et al., “Surface Mobility and Slip of Polybutadiene Melts in Shear Flow”, J. Rheol., 44, 549–567(2000), DOI: 10.1122/1.551100Suche in Google Scholar
© 2010, Carl Hanser Verlag, Munich
Artikel in diesem Heft
- Contents
- Contents
- Editorial
- Professor James Lindsay White 1938–2009
- Regular Contributed Articles
- Effect of Clay on Thermal, Mechanical and Gas Barrier Properties of Biodegradable Poly(lactic acid)/Poly(butylene succinate) (PLA/PBS) Nanocomposites
- Thermo-mechanical Properties of Urea-based Pattern Molding Compounds for Investment Casting
- Erosion Wear Analysis of SiC Filled Glass-Epoxy Composites using Taguchi Technique
- Production and Characterization of PP/LDPE Blend Filament Yarns under Industrial Conditions
- Modelling Post-molding Warping
- Modelling Post-molding Warping
- Appropriate Boundary Conditions in the Flow of Molten Polymers
- Multiscale Simulation of Injection Molding of Parts with Low Aspect Ratio Microfeatures
- PPS-News
- PPS News
- Seikei Kakou Abstracts
- Seikei-Kakou Abstracts
- Polímeros: Ciência e Tecnologia Abstracts
- Polímeros: Ciência e Tecnologia – Abstracts
Artikel in diesem Heft
- Contents
- Contents
- Editorial
- Professor James Lindsay White 1938–2009
- Regular Contributed Articles
- Effect of Clay on Thermal, Mechanical and Gas Barrier Properties of Biodegradable Poly(lactic acid)/Poly(butylene succinate) (PLA/PBS) Nanocomposites
- Thermo-mechanical Properties of Urea-based Pattern Molding Compounds for Investment Casting
- Erosion Wear Analysis of SiC Filled Glass-Epoxy Composites using Taguchi Technique
- Production and Characterization of PP/LDPE Blend Filament Yarns under Industrial Conditions
- Modelling Post-molding Warping
- Modelling Post-molding Warping
- Appropriate Boundary Conditions in the Flow of Molten Polymers
- Multiscale Simulation of Injection Molding of Parts with Low Aspect Ratio Microfeatures
- PPS-News
- PPS News
- Seikei Kakou Abstracts
- Seikei-Kakou Abstracts
- Polímeros: Ciência e Tecnologia Abstracts
- Polímeros: Ciência e Tecnologia – Abstracts