Band formation upon cessation of flow in liquid-crystalline polymers

Journal of Rheology

Volumn 38, Issue 5, 1994, Pages 1571-1589

  Picken, S J ^b   Moldenaers, P ^a   Mewis, J ^a  

^a UNIVERSITY OF LEUVEN   (Belgium)

^b AKZO NOBEL CENTRAL RESEARCH   (Netherlands)

Author keywords

[No Author keywords available]

Indexed keywords

FLOW OF FLUIDS; KINETIC THEORY; LIQUID CRYSTALS; POLYMERS; SOLUTIONS; TEXTURES;

BAND FORMATION; CESSATION; LIQUID CRYSTALLINE POLYMERS; SHEAR RATE;

RHEOLOGY;

EID: 0028514251     PISSN: 01486055     EISSN: 15208516     Source Type: Journal    
DOI: 10.1122/1.550560     Document Type: Article

References (46)

1. Burghardt, W. R. and G. G. Fuller, ‘Transient shear flow of nematic liquid crystals: Manifestations of director tumbling’ J. Rheol. 34, 959–992 (1990).
2. Chan, P. K. and A. D. Rey, “Simulation of transient banded textures of sheared nematic polymers’ Liq. Cryst. 12, 1025–1028 (1992).
3. Chan, P. K. and A. D. Rey, “A study on the relaxation phenomena of nematic polymers after cessation of flow,” Liq. Cryst. 13, 775–795 (1993).
4. Dobb, M. G., D. J. Johnson, and B. P. Saville, “Direct observation of structure in high-modulus aromatic fiber,” J. Polym. Sci. Polym. Symp. 58, 237–251 (1977a).
5. Dobb, M. G., D. J. Johnson, and B. P. Saville, “Supramolecular structure of a polyaromatic fiber (Kevlar 49),” J. Polym. Sci. Polym. Phys. Ed. 15, 2201–2211 (1977b).
6. Donald, A. M., C. Viney, and A. H. Windle, “Banded structures in oriented thermotropic polymers,” Polymer 24, 155–159 (1983).
7. Donald, A. M. and A. H. Windle, “Electron Microscopy of banded structures in oriented thermotropic polymers,” J. Mater. Sci. 18, 1143–1150 (1983).
8. Donald, A. M., C. Viney, and A. P. Ritter, “The parabolic focal conic texture in a lyotropic liquid crystalline polymer,” Liq. Cryst. 1, 287–300 (1986).
9. Ernst, B. and P. Navard, “Band textures in mesomorphic (hydroxypropyl)cellulose solutions,” Macromolecules 22, 1419–1422 (1989).
10. Fincher, C. R., “Light diffraction studies of the banded texture in hydroxypropylcellulose,” Mol. Cryst. Liq. Cryst. 155, 559–570 (1988).
11. Gleeson, J. T., R. G. Larson, D. W. Mead, G. Kiss, and P. E. Cladis, “Image analysis of shear-induced textures in liquid crystalline polymers’ Liq. Cryst. 11, 341—364 (1992).
12. Graziano, D. J. and M. R. Mackley, “Shear induced optical structures and their relaxation behavior in thermotropic liquid crystalline polymers,” Mol. Cryst. Liq. Cryst. 106, 73–93 (1984).
13. Grizzuti, N., P. Moldenaers, M. Mortier, and J. Mewis, “On the time-dependency of the flow-induced dynamic moduli of a liquid crystalline hydroxypropylcellulose solution’ Rheol. Acta 32, 218–226 (1993).
14. Hongladarom, K. and W. R. Burghardt, “Molecular alignment of polymer liquid crystals in shear flows. 2. Transient flow behavior in poly(benzyl glutamate) solutions” Macromolecules 26, 785–794 (1993).
15. Hoho, M., S. Ishikawa, and K. Oda, “Fine structure of fibers and films made from lyotropic liquid crystals of polymers’ J. Appl. Polym. Sci. Appl. Polym. Symp. 41, 269–292 (1985).
16. Kiss, G. and R. S. Porter, “Rheo-optical studies of liquid crystalline solutions of helical polypeptides’ Mol. Cryst. Liq. Cryst. 60, 267–280 (1980).
17. Larson, R. G. and D. W. Mead, “Time and shear-rate scaling laws for liquid crystal polymers,” J. Rheol. 33, 1251–1281 (1989).
18. Larson, R. G. and D. W. Mead, “Development of orientation and texture during shearing of liquid-crystalline polymers,” Liq. Cryst. 12, 751–768 (1992).
19. Larson, R. G. and D. W. Mead, “The Ericksen number and Deborah number cascades in sheared polymeric nematics, Liq. Cryst. 15, 151–169 (1993).
20. Lee, S. and R. B. Meyer, “Elastic and viscous properties of lyotropic polymernematics’ in Liquid Crystallinity in Polymers, edited by A. Ciferri (VCH, New York, 1991), Chap. 9, pp. 343–364.
21. Maffetone, P. L., N. Grizzuti, and G. Marrucci, “Band formation in HPC solutions by consecutive shears along orthogonal directions,” Liq. Cryst. 4, 385–391 (1989).
22. Marrucci, G., “Rheology of liquid crystalline polymers,” Pure Appl. Chem. 57, 1545–1552 (1985).
23. Marrucci, G., N. Grizzuti, and A. Buonaurio, “Band formation in sheared HPC solutions. Effects of sample thickness’ Mol. Cryst. Liq. Cryst. 153, 263–269 (1987).
24. Marrucci, G. and F. Greco, “The flow behavior of liquid crystalline polymers,” Adv. Chem. Phys. 86, (1993).
25. Marrucci, G. and P. L. Maffetone, “LCP defect dynamics in shear flows,” Proceedings of the Third International Workshop on LCPs, edited by C. Carfanaga (Pergamon, New York, 1994) (in press).
26. Marsano, E., L. Carpaneto, and A. Ciferri, “Formation of a banded texture in solutions of liquid crystalline polymers: 1 Hydroxypropylcellulose in H20,” Mol. Cryst. Liq. Cryst. 158b, 267–278 (1988a).
27. Marsano, E., L. Carpaneto, A. Ciferri, and Y. Wu, “Formation of a banded texture in solutions of liquid crystalline polymers: 2. Poly (n- hexyl isocyanate) in toluene,” Liq. Cryst. 3, 1561–1567 (1988b).
28. Marsano, E., L. Carpaneto, and A. Ciferri, “Formation of a banded texture in solutions of liquid crystalline polymers: 3. Poly(p-benzamide) in n, n dimethylacetamide/lithium chloride,” Mol. Cryst. Liq. Cryst. 177, 93–99 (1989).
29. Mewis, J. and P. Moldenaers, “Effect of temperature on the rheology of polymeric liquid crystals’ Chem. Eng. Commun. 53, 33–47 (1987).
30. Moldenaers, P. and J. Mewis, “Transient behavior of liquid crystalline solutions of poly(benzylglutamate),” J. Rheol. 30, 567–584 (1986).
31. Moldenaers, P. (1994) (to be published).
32. Navard, P., “Formation of band textures in hydroxypropylcellulose liquid crystals,” J, Polym. Sci. Polym. Phys. Ed. 24, 435–442 (1986).
33. Navard, P., paper presented at he Xlth International Congress on Rheology, Brussels, 1992 (unpublished).
34. Odell, J. A., G. Ungar, and J. L. Feijoo, “A rheological, optical and x-ray study of the relaxation of orientation of nematic PBZT,” J, Polym. Sci. Part B: 31, 141–155 (1993).
35. Picken, S. J., J. Aerts, H. L. Doppert, A. J. Reuvers, and M. G. Northolt, “Structure and rheology of aramid solutions: Transient rheological and rheo-optical measurements,” Macromolecules 24, 1366–1375 (1991).
36. Picken, S. J., P. Moldenaers, S. Berghmans, and J. Mewis, “Experimental and theoretical analysis of band formation in polymeric liquid crystals upon cessation of flow,” Macromolecules 25, 4759–4767 (1992).
37. Qian, R. and S. Chen, “Band texture formation of sheared polymeric liquid crystalline state,” Makromol. Chem., Macromol. Symp. 53, 345–354 (1992).
38. Takebe, T., T. Hashimoto, B. Ernst, P. Navard, and R. S. Stein, “Small-angle light scattering of polymer liquid crystals under shear flow,” J. Chem. Phys. 92, 1386–1396 (1990).
39. Takeuchi, Y., Y. Shuto, and F. Yamamoto, “Band pattern development in shear-oriented thermotropic copolyester extrudates,” Polymer 29, 605–611 (1988).
40. Vermant, J., P. Moldenaers, S. Picken, and J. Mewis, “A comparison between texture and rheological behavior of lyotropic liquid crystalline polymers during flow’ J. Non-Newt. Fluid Mech. (1994) (in press).
41. Viney, C., A. M. Donald, and A. H. Windle, “Optical microscopy of banded structures in oriented thermotropic polymers’ J. Mater. Sci. 18, 1136–1142 (1983).
42. Viney, C., “Light microscopy of liquid crystalline polymers,” in Liquid Crystalline Polymers, edited by R. A. Weiss and C. K. Ober, ACS Symp. Series 435 (American Chemical Society, Washington, DC, 1989).
43. Wang, J. and M. M. Labes, “Control of the anisotropic properties of liquid crystal polymer films by variations in their banded texture,” Macromolecules 25, 5790—5793 (1992).
44. Xu, G., W. Wu, M. Xu, and Q. Zhou, “Banded texture in oriented films of a sidechain liquid-crystalline polymer,” J. Polym. Sci. Part B 31, 229–230 (1993a).
45. Xu, G., W. Wu, D. Shen, J. Hou, S. Zhang, M. Xu, and Q. Zhou, “Morphological study of oriented films obtained from side-chain liquid crystalline polymers, Polymer 34, 1818–1822 (1993b).
46. Zachariades, A., P. Navard, and J. A. Logan, “Deformation studies of liquid cjystalline polymers,” Mol. Cryst. Lia. Crvst. 110, 93–107 (1984).