Polypropylene layered silicate properties

Lee, S. H., and Youn, J. R., Properties of polypropylene/layered-silicate nanocomposites and melt-spun fibers, J. Appl. Polym. Sci, 109, 1221-1231 (2008). 

Mittal, V. 2007. Polypropylene-layered silicate nanocomposites Filler matrix interactions and mechanical properties. Journal of Thermoplastic Composite Materials 20 575-599. 

Parija, S., Nayak, S. K., Verma, S. K., and Tripathy, S. S. 2004. Studies on physico-mechanical properties and thermal characteristics of polypropylene/layered silicate nanocomposites. Polymer Composites 25 646-652. 

Dubnikova, I. L., Berezina, S. M., Korolev, Y. M., Kim, G. M., and Lomakin, S. M. 2007. Morphology, deformation behavior and thermomechanical properties of polypropylene/maleic anhydride grafted polypropylene/layered silicate nanocomposites. 

L. Cauvin, D. Kondo, M. Brieu, N. Bhatnagar, Mechanical properties of polypropylene layered silicate nanocomposites characterization and micro-macro modelling. Polymer Testing 29 (2) (2010) 245-250. 

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Koo CM, Kim MJ, Choi MH, Kim SO, Chung IJ (2003) Mechanical and rheological properties of the maleated polypropylene-layered silicate nanocomposites with different morphology. J ApplPolym Sci 88(6) 1526-1535... 

Even after organic modification of the clays, polypropylene does not wet the surface of clays because it is nonpolar. It is necessary to blend in a functionalized polymer such as maleated polypropylene (PP-g-MA) that wets the modified clay surface more readily and is also miscible with the bulk polymer. Okada and coworkers were the first to produce polypropylene layered silicate nanocomposites by melt compounding the modified elay with PP-g-MA and PP. The progress made since then in preparing and characterizing polypropylene layered silicate nanocomposites is reviewed in this chapter. We discuss advances in formulations, preparation methods and characterization then proceed to effects of the dispersion state (intercalated vs. exfoliated) and of silicate loading on crystallinity, mechanical performance and other properties, and end with a summary of progress to date with these composites. All the results presented in this chapter refer to isotactic polypropylene nanocomposites with layered or smectite clays. 

New trends involve the use of nanoparticles in synthetic fibers. Polymer-layered silicates, nanotubes, and POSS have been successfully introduced in a number of textile fibers, mainly poly-amide-6, polypropylene, and polyester. Although they reduce the flammability of these fibers, but on their own are not effective enough to confer flame retardancy to a specified level. However, in presence of small amounts of selected conventional FRs (5-10 wt %), synergistic effect can be achieved. With this approach fibers having multifunctional properties can also be obtained, e.g., water repellency or antistatic properties along with fire retardancy. Most of the work in this area at present is on the lab scale and there is a potential to take this forward to a commercial scale. 

Gilman, J.W. Jackson, C.L. Morgan, A.B. Harris, R. Manias, E. Giannelis, E.P. Wuthenow, M. Hilton, D. Phillips, S.H. Flammability properties of polymer-layered-silicate nanocomposites. Polypropylene and polystyrene nanocomposites. Chem. Mater. 2000, 12, 1866-1873. 

J.W. Gilman, C.L. Jackson, A.B. Morgan, R. Harris Jr., Flammabihty properties of polymer— layered silicate nanocomposites polypropylene and polyst3 rene nanocomposites. Chem. Mater. 12, 1866-1873 (2000)... 

Gorras, G., Tortora, M., Vittoria, V., Kaempfer, D., and Mulhaupt, R. 2003. Transport properties of organic vapors in nanocomposites of organophilic layered silicate and syndiotactic polypropylene. Polymer 44 3679-3685. 

Sumita M, Tsukumo Y, Miyasaka K et al (1983) Tensile yield stress of polypropylene composites filled with ultrafine particles. J Mater Sci 18 1758—1764 Thellen C, Orroth C, Froio D et al (2005) Influence of montmorillonite layered silicate on plasticized poly(l-lactide) blown films. Polymer 46 1716-11727 Uyama H, Kuwabara M, Tsujimoto T et al (2003) Green nanocomposites from renewable resources plant oil-clay hybrid materials. Chem Mater 15 2492-2494 Wang SF, Shen L, Zhang WD et al (2005a) Preparation and mechanical properties of chitosan/ carhon nanotuhes composites. Biomactomolecules 6 3067—3072... 

P. Motamedi, R. Bagheri, Investigation of the nanostructure and mechanical properties of polypropylene/polyamide 6/layered silicate ternary nanocomposites. Materials and Design 31 (4) (2010) 1776-1784. 

J. W. Gilman, C. L. Jackson, A. B. Morgan, R. Harris, Jr., E. Manias, E. P. Giannelis, M. Wuthenow, D. Hilton, and S. H. Phillips, Flammability properties of polymer-layered-silicate nanocomposites Polypropylene and polystyrene nanocomposites. Chemistry... 

Lee S, Hong J-Y, Jang J (2003) The effect of graphene nanofiller on the crystallization behavior and mechanical properties of poly(vinyl alcohol). Polym Int 62 901-908 Lele A, Mackley M, Galgali G, Ramesh C (2002) In situ rheo-x-ray investigation of flow-induced orientation in layered silicate-syndiotactic polypropylene nanocomposite melt. J Rheol 46 1091-1110... 

Gilman J. W., Jackson C. L., Morgan A. B., Hayyis R., Jr, Manias E. et al. (2000), Flammability Properties of Polymer-Layered-Silicate Nanocomposites and Polypropylene and Polystyrene Nanocomposites. C/rcw Mater, 12,1866-73. 

Intercalated nanocomposites are usually formed by mixing in the melt or in situ polymerisation whereas exfoliation may require more complex processing depending on the properties of the clay (Usuki et al, 1993). However, such layered silicate-based polymer nanocomposites have attracted considerable recent interest after the commercialisation of polypropylene-and nylon-6-based materials (Krishnamoorti and Yurekli, 2001, Kiersnowski and Piglowski, 2004). The major barrier to commercialisation has been developing techniques to ensure a reliable and reproducible product which has now been addressed for clay-based composites some thirty or so years after they were first developed. 

The structure and properties of layered silicate polypropylene nanocomposites... 

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