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Structure and properties of polypropylene/organic rectorite nanocomposites

Published online by Cambridge University Press:  09 July 2018

Yun Huang*
Affiliation:
School of Materials Science and Engineering, Southwest Petroleum University, Chengdu, Sichuan, 610500, China
Xiaoyan Ma
Affiliation:
Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
Guozheng Liang
Affiliation:
Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
Hongxia Yan
Affiliation:
Department of Applied Chemistry, School of Science, Northwestern Polytechnical University, Xi'an, Shaanxi, 710072, China
*

Abstract

Melt blending using a twin-screw extruder was used to prepare composites of polypropylene (PP)/organic rectorite (PR). The organic rectorite (OREC) was modified with dodecyl benzyl dimethyl ammonium bromide (1227). Wide-angle X-ray diffraction (WAXD) and transmission electron microscopy were used to investigate the dispersion of OREC in the composites. The d spacings of OREC in PR composites was greater than in OREC itself. The dispersion of OREC particles in the PP polymer matrix was fine and uniform when the clay content was small (2 wt.%). The rheology was characterized using a capillary rheometer. The processing behaviour of the PR system improved as the amount of OREC added increased. Non-isothermal crystallization kinetics were analysed using differential scanning calorimetry. It was shown that the addition of OREC had a heterogeneous nucleation effect on PP, and can accelerate the crystallization. However, only when fine dispersion was achieved, and at lower rates of temperature decrease, was the crystallinity greater. Wide-angle X-ray diffraction and polarized light microscopy were used to observe the crystalline form and crystallite size. The PP in the PR composites exhibited an a-monoclinic crystal form, as in pure PP, and in both cases a spherulite structure was observed. However, the smaller spherulite size in the PR systems indicated that addition of OREC can reduce the crystal size significantly, which might improve the ‘toughness’ of the PP. The mechanical properties (tensile and impact strength) improved when the amount of OREC added was appropriate. Dynamic mechanical analysis showed that the storage modulus (E′) and loss modulus (E″) of the nanocomposites were somewhat greater than those of pure PP when an appropriate amount of OREC was added. Finally, thermogravimetric analysis showed that the PR systems exhibited a greater thermal stability than was seen with pure PP.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2009

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References

Causin, V., Marigo, A., Ferrara, G. & Ferraro, A. (2006) Morphological and structural characterization of polypropylene/conductive graphite nanocomposites. European Polymer Journal, 42, 31533161.CrossRefGoogle Scholar
Chiu, F.C. (2004) Combined effects of clay modifications and compatibilizers on the formation and physical properties of melt-mixed polypropylene/clay nanocomposites. Journal of Polymer Science, B: Polymer Physics, 42, 41394150.CrossRefGoogle Scholar
Chung, M.J. (2005) Preparation and characterization of maleic anhydride-γ-polypropylene/diamine-modified clay nanocomposites. Journal of Applied Polymer Science, 95, 307311.CrossRefGoogle Scholar
Deshmane, C., Yuan, Q. & Misra, R.D.K. (2007) On the fracture characteristics of impact tested high density polyethylene—calcium carbonate nanocomposites. Materials Science and Engineering A, 452-453, 592601.CrossRefGoogle Scholar
Ding, N.X. (2004) Magnetostrictive properties of carbon black filled polypropylene composites. Polymer Testing, 23, 523526.Google Scholar
Fornes, T.D., Hunter, D.L.. & Paul, D.R. (2004) Nylon-6 nanocomposites from alkylammonium-modified clay: the role of alkyl tails on exfoliation. Macromolecules, 37, 17931798.CrossRefGoogle Scholar
Hong, C.H. (2005) Preparation and mechanical properties of polypropylene/clay nanocomposites for automotive parts application. Journal of Applied Polymer Science, 98, 427433.Google Scholar
Jang, L.W. (2005) Preparation and characterization of polypropylene/clay nanocomposites with polypropylene-graft-maleic anhydride. Journal of Applied Polymer Science, 98, 12291234.Google Scholar
Ma, X.Y., Lu, H.J., Liang, G.Z. & Yan, H.X. (2004) Rectorite/thermoplastic polyurethane nanocomposites: preparation, characteriazation, and properties. Journal of Applied Polymer Science, 93, 608614.Google Scholar
Ma, X.Y., Lu, H.J., Liang, G.Z., Zhao, J.C. & Lu, T.L. (2005) Rectorite/thermoplastic polyurethane nanocomposites: II. Improvement of thermal and oil resistant properties. Journal of Applied Polymer Science, 96, 11651169.CrossRefGoogle Scholar
Park, C., Smith, J.G. & Connell, J.W. (2005) Polyimide/silica hybrid-clay nanocomposites. Polymer, 46, 96949701.Google Scholar
Rosa, D.S., Agnelli, J.A.M. & Mei, L.H.I. (2005) The use of optical microscopy to follow the degradation of isotactic polypropylene (iPP) subjected to natural and accelerated ageing. Polymer Testing, 24, 10221026.CrossRefGoogle Scholar
Shelley, J.S. & DeVries, K.L. (2001) Reinforcement and environmental degradation of nylon-6/clay nanocomposites. Polymer, 42, 58495858.Google Scholar
Tang, Y. (2003) Preparation and thermal stability of polypropylene/montmorillonite nanocomposites. Polymer Degradation and Stability, 82,127-131.Google Scholar
Vaia, R.A., Ishii, H. & Giannelis, E.P. (1993) Synthesis and properties of two-dimensional nano structures by direct intercalation of polymer melts in layered silicates. Chemistry of Materials, 5, 16941696.Google Scholar
Vaia, R.A., Ruth, P.N., Nguyen, H.T. & Lichtenhan, J. (1999) Polymer/layered silicate nanocomposites as high performance ablative materials. Applied Clay Science, 15, 6792.Google Scholar
Varela, C. (2006) Functionalized polypropylenes in the compatibilization and dispersion of clay nanocomposites. Polymer Composites, 27, 451460.CrossRefGoogle Scholar
Voskoboinikov, R.E. (1999) Degradation of mechanical properties of structural reactor materials induced by formation of stress concentrators. Journal of Nuclear Materials, 270, 309314.Google Scholar
Wang, Y., Chen, F.B. & Wu, K.C. (2005) Melt intercalation and exfoliation of maleated polypropylene modified polypropylene nanocomposites. Composite Interfaces, 12, 341363.Google Scholar
Weng, W.G., Chen, G.H. & Wu, D.J. (2003) Crystallization kinetics and melting behaviors of nylon 6/foliated graphite nanocomposites. Polymer, 44, 81198132.Google Scholar
Xiang, Y.Q. & Chen, D.J. (2006) A new polymer/clay nano-composite hydrogel with improved response rate and tensile mechanical properties. European Polymer Journal, 42, 21252132.Google Scholar
Xu, T., Lei, H. & Xie, C.S. (2003) The effect of nucleating agent on the crystalline morphology of polypropylene (PP). Materials & Design, 24, 227230.CrossRefGoogle Scholar
Yuana, Q. & Misra, R.D.K. (2006) Impact fracture behavior of clay-reinforced polypropylene nanocomposites. Polymer, 47, 44214433.CrossRefGoogle Scholar
Zhang, J.G., Wang, D.Y. & Wilkie, C.A. (2006) Styrenic polymer nanocomposites based on an oligomerically-modified clay with high inorganic content. Polymer Degradation and Stability, 91, 26652674.Google Scholar
Zhang, Q.X., Yu, Z.Z., Xie, X.L.. & Mai, Y.W. (2004) Crystallization and impact energy of polypropylene/CaCO3 nanocomposites with nonionic modifier. Polymer, 45, 59855994.Google Scholar