Abstract
The morphology development in dilute and semi-concentrated blends (2 and 15 wt% disperse phase) of viscoelastic polymers is studied during flow in dies. In the entrance region the droplets deform into fibrils. In the die itself some of the fibrils can break up depending on their shear history and hence on their radial position. The morphology at the exit of the die is investigated by quenching the extrudate and visualizing the structure via scanning electron microscopy (SEM). For fibrils moving along the die axis, the theory of Tomotika for break-up of a fibril in a quiescent matrix describes the observations satisfactorily. Fibrils flowing off center undergo a shearing flow in the die, which could have an effect on the growth of the Rayleigh disturbances that cause break-up. It is observed that during flow break-up still occurs via Rayleigh instabilities. As a first approximation the theory of Tomotika also predicts the break-up of fibrils flowing off center, if the viscosity at the relevant shear rate is used.
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References
Alle N, Lyngaae-Jorgensen J (1980a) Polypropylene and polyethylene blends. 1. Flow behavior in capillaries. Rheol Acta 19:94–103
Alle N, Lyngaae-Jorgensen J (1980b) Polypropylene-polyethylene blends. 2. Relationship between rheology and morphology in capillary-flow. Rheol Acta 19:104–110
Alle N, Andersen FE, Lyngaae-Jorgensen J (1981) Polypropylene-polyethylene blends. 3. Die swell behavior and morphology after capillary-flow. Rheol Acta 20:222–230
de Bruijn R (1989) Deformation and break-up of drops in simple shear flows. Ph.D. thesis, T.U. Eindhoven
Elemans PHM, Bos HL, Janssen JMH, Meijer HEH (1993) Transient phenomena in dispersive mixing. Chem Eng Sci 48:267–276
Elemans PHM, van Wunnik JM, van Dam RA (1997) Development of morphology in blends of immiscible polymers. AIChE J 43:1649–1651
Grace HP (1982) Dispersion phenomena in high-viscosity immiscible fluid systems and application of static mixers as dispersion devices in such systems. Chem Eng Commun 14:225–277
Gramespacher H, Meissner J (1992) Interfacial-tension between polymer melts measured by shear oscillations of their blends. J Rheol 36:1127–1141
Gramespacher H, Meissner J (1997) Melt elongation and recovery of polymer blends, morphology, and influence of interfacial tension. J Rheol 41:27–44
Han JH, Chin CF, Li DJ, Han CD (1995) Effect of flow geometry on the rheology of dispersed 2-phase blends of polystyrene and poly(methyl-methacrylate). Polymer 36:2451–2462
Huneault MA, Champagne MF, Luciani A (1996) Polymer blend mixing and dispersion in the kneading section of a twin-screw extruder. Polym Eng Sci 36:1694–1706
Incropera F, Dewitt W (1996) Fundamentals of heat and mass transfer, 4th edn. Wiley, New York
Janssen JMH, Meijer HEH (1993) Droplet breakup mechanisms—stepwise equilibrium versus transient dispersion. J Rheol 37:597–608
Khakhar DV, Ottino JM (1987) Breakup of liquid threads in linear flows. Int J Multiph Flow 13:71–86
Knops YMM, Slot JJM, Elemans PHM, Bulters MJH (2001) Simultaneous breakup of multiple viscous threads surrounded by viscous liquid. AIChE J 47:1740–1745
Kuhn W (1953) Spontane aufteilung von fluessigkeitszylindern in kleine kugeln. Kolloid Z 132:84–99
Lacroix C, Grmela M, Carreau PJ (1999) Morphological evolution of immiscible polymer blends in simple shear and elongational flows. J Non-Newt Fluid Mech 86:37–59
Lyngaae-Jorgensen J, Andersen F, Alle N (1983) Domain stability during capillary flow of well dispersed two phase polymer blends. Polystyrene/polymethylmethacrylate blends. In: Klempner D, Frisch K (eds) Polymer alloys III. Plenum, New York, pp 105–147
Mikami T, Cox R, Mason S (1975) Breakup of extending liquid threads. Int J Multiphase Flow 2:113–138
Palierne JF (1990) Linear rheology of viscoelastic emulsions with interfacial- tension. Rheol Acta 29:204–214
Tomotika S (1935) On the instability of a cylindrical thread of a viscous liquid surrounded by another viscous fluid. Proc Roy Soc (London) A150:322–337
Tomotika S (1936) Breaking of a drop of a viscous liquid immersed in another viscous fluid which is extending at a uniform rate. Proc Roy Soc (London) A153:302–318
Utracki LA, Shi ZH (1992) Development of polymer blend morphology during compounding in a twin-screw extruder. 1. Droplet dispersion and coalescence—a review. Pol Eng Sci 32:1824–1833
Van Puyvelde P (1999) Flow-induced morphology changes in immiscible polymer blends: a rheo-optical study. Ph.D. thesis, K.U. Leuven
Van Puyvelde P, Yang H, Mewis J, Moldenaers P (2000) Breakup of filaments in blends during simple shear flow. J Rheol 44:1401–1415
Vinckier I, Mewis J, Moldenaers P (1997) Stress relaxation as a microstructural probe for immiscible polymer blends. Rheol Acta 36:513–523
Vinckier I, Moldenaers P, Terracciano AM, Grizzuti N (1998) Droplet size evolution during coalescence in semiconcentrated model blends. AIChE J 44:951–958
Wagner MH, Stephenson SE (1979) Irreversibility assumption of network disentanglement in flowing polymer melts and its effects on elastic recoil predictions. J Rheol 23:489–504
Wu S (1970) Polymer interface and adhesion. ii polymethylmethacrylate, poly-n-butylmethacrylate and polystyrene. J Phys Chem 74:632–638
Acknowledgements
We like to thank BASF Aktiengesellschaft for providing the materials and for financial support. Research financed with a scholarship of the Flemish Institute for the advancement of scientific–technological research in industry (IWT) and the Research Council of the K.U.Leuven (GOA 98/06 and 03/06). Gerhard Schmidt of BASF Aktiengesellschaft is kindly thanked for the Polyflow calculations.
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Oosterlinck, F., Vinckier, I., Mours, M. et al. Morphology development of a PS/PMMA polymer blend during flow in dies. Rheol Acta 44, 631–643 (2005). https://doi.org/10.1007/s00397-005-0445-4
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DOI: https://doi.org/10.1007/s00397-005-0445-4