Effect of Shear Flow on Crystallization of Sydiotactic Polypropylene/Clay Composites

N. Ahmad, E. Fouad, F. Ahmad

Abstract


The high sensitivity of crystallization to shear flow is a subject of great research interest the last several years. A set of syndiotactic polypropylene/clay composite samples were used to examine the effect of shear flow on crystallization kinetics. This phenomenon alters both processing and material final properties. In the present work, the effects of clay contents and shear flow on the rate of flow induced crystallization were investigated using rheological technique. Small amplitude oscillatory shear experiments were performed using advanced rheometric expansion system (ARES). The crystallization rate is found to alter by both shear and clay contents in the polymer composites.


Keywords


shear flow; flow induced crystallization; syndiotactic polypropylene/clay composites; induction time; Deborah number; crystallization kinetics

Full Text:

PDF

References


H. Janeschitz-Kriegl, E. Ratajski, M. Stadlbauer, “Flow as an effective promotor of nucleation in polymer melts: A quantitative evaluation”, Rheological Acta, Vol. 42, No. 4, pp. 355–364, 2003

R. H. Somani, L. Yang, B. S. Hsiao, T. Sun, N. V. Pogodina, A. Lustiger, “Shear-induced molecular orientation and crystallization in isotactic polypropylene: Effects of the deformation rate and strain”, Macromolecules, Vol. 38, No. 4, pp. 1244–1255, 2005

R. H. Somani, L. Yang, L. Zhu, B. S. Hsiao, “Flow-induced shish-kebab precursor structures in entangled polymer melts”, Polymer, Vol. 46, No. 20, pp. 8587–8623, 2005

E. W. Fischer, M. Stamm, M. Dettenmair, “Organization of the Macromolecules in the condensed Phase”, in: Faraday Discussions of the Royal Society of Chemistry, Vol. 68, 1980

J. Stejny, J. Dlugosz, A. Keller, “Electron microscope diffraction characterization of the fibrous structure of poly (sulphur nitride) crystals”, Journal of Materials Science, Vol. 14, No. 6, pp. 1291–1300, 1979

S. T. Milner, T. C. B. Mc Leish, “Reptation and contour-length fluctuations in melts of linear polymers”, Physical Review Letters, Vol. 81, No. 3, pp. 725–728, 1998

J. I. Lauritzen Jr, J. D. Hoffman, “Formation of polymer crystals with folded chains from dilute solution”, The Journal of Chemical Physics, Vol. 31, No. 6, pp. 1680–1681, 1959

S. Acierno, N. Grizzuti, H. H. Winter, “Effects of Molecular Weight on the Isothermal Crystallization of Poly(1-butene)”, Macromolecules, Vol. 35, No. 13, pp. 5043–5048, 2002

S. Acierno, N. Grizzuti, “Flow-induced crystallization of polymer: theory and experiments”, International Journal of Material Forming, Vol. 1, pp. 583–586, 2008

C. Duplay, B. Monasse, J. M. Haudin, J. L. Costa, “Shear-induced crystallization of polypropylene: Influence of molecular weight”, Journal of Materials Science, Vol. 35, No. 24, pp. 6093–6103, 2000

S. Vleeshouwers, H. E. H. Meijer, “A rheological study of shear induced crystallization”, Rheological Acta, Vol. 35, No. 5, pp. 391–399, 1996

M. Khalil, P. Hebraud, A. Mcheik, H. Mortada, H. Lakiss, T. Hamieh, “Elongational flow-induced crystallization in polypropylene/talc nanocomposites”, Physics Procedia, Vol. 55, pp. 259–264, 2014

L. Zhang, Y. Qin, G. Zheng, K. Dai, C. Liu, X. Yan, J. Guo, C. Shen, Z. Guo, “Interfacial crystallization and mechanical property of isotactic polypropylene based single-polymer composites”, Polymer (UK), Vol. 90, pp. 18–25, 2016

F. Hernandez Sanchez, L. F. del Castillo, R. Vera-Graziano, “Isothermal crystallization kinetics of polypropylene by differential scanning calorimetry, I. Experimental conditions”, Journal of Applied Polymer Science, Vol. 92, pp. 970-978, 2004




eISSN: 1792-8036     pISSN: 2241-4487