Polypropylene-clay nanocomposites

In contrast to the results above for PS-MMT nanocomposite chars from pure maleic anhydride, grafted PP (PP-g-MA) nanocomposites produce a featureless 

FLAME RETARDANT MECHANISM OF POLYMER-CLAY NANOCOMPOSITES 

FIGURE 3.12 Mass fraction (%) loss in TGA (in N2 and air) for surface region clay-chars at various gasification exposure times. See insert for color representation 

FIGURE 3.13 TEM of the combustion char of a PP-g-MA/MMT clay nanocomposite (4% mass fraction MMT), revealing the disordered structure of the clay in the residue. 

FIGURE 3.14 Digital images of nitrogen gasification residues from three nanocomposites a) PP/mass fraction 5% MMT b) PP/mass fraction 15% PP-g-MA/mass fraction 2% MMT (c) PP/mass fraction 15% PP-g-MA/mass fraction 5% MMT. 

---

Preparation and properties of polypropylene/clay nanocomposites, Journal of Materials Research 8 11-47. 

R. Kozlowski, M. Wladyka-Przybylak, and H. Rydarowski, Flammability of polypropylene/clay nanocomposites-synergism with some flame retardants, Proceedings of the 17th BCC Conference on Flame Retardancy, M. Lewin (Ed.), Business Communications Co Editions, Norwalk, CT, 2006. 

Oya A. Polypropylene clay nanocomposites. In Pinnavaia TJ, Beall GW, editors. Polymer clay nanocomposites. London Wiley 2000. 

Nam, R H., Maiti, R, Okamoto, M., Kotaka, T., Nakayama, T., Takada, M., Ohshima, M., Usuki, A., Hasegawa, N., and Okamoto, H., Foam processing and cellular structure of polypropylene/clay nanocomposites, Polym. Eng. ScL, 42, 1907-1918 (2002). Navarro-Banon, V., Vega-Baudrit, J., Vaquez, R, and Martm-Martinez, J. M., Interactions in naosilica-polyurethane composites evidenced by plate-plate rheology and DMTA, Macro-mol. Symp., 221, 1-10 (2005). 

Okamoto, M., Nam, P. H., Maiti, R, Kotaka, T., Hasegawa, N., and Usuki, A., A house of cards structure in polypropylene/clay nanocomposites under elongational flow. Nano Lett., 1, 295-298 (2001b). 

Kim, S.J. Moon, J.B. Kim, G.H. Ha, C.S. (2008). Mechanical Properties of Polypropylene/Natural Fiber Composites Comparison of Wood Fiber and Cotton Fiber. Polymer Testing, Vol.27, No. 7, (October 2008), pp. 801-806, ISSN 0142-9418 Kotek, J. Kelnar, L Studenovsky, M. Baldrian J. (2005). Chlorosulfonated polypropylene preparation and its application as a coupling agent in polypropylene-clay nanocomposites. Polymer, Vol. 46, No. 16, (June 2005), pp. 4876-4881, ISSN 0032-3861... 

Garda-Leiner, M. Lesser, A. (2004) C02-assisted polymer processing A new alternative for intractable polymers.. Appl. Polym. Sci. Vol.93, No.4, pp.1501-1511 Garcia-Lop>ez, D. Picazo, O. Merino, J. Pastor, J. (2003) Polypropylene Clay Nanocomposites Effed of Compatibilizing Agents on Clay Dispjersion. Ew. Polym.. Vol.39, No.5, p>p.945-950... 

Zhao, Y. Huang, H. (2008) Dynamic rheology and microstructure of polypropylene/ clay nanocomposites prepared under SC-CO2 by melt compounding. Polym. Test. Vol.27, No.l, pp.129-134... 

Nam P. H. Okamoto M. Kotaka T. Hasegawa N. Usuki, A. A hierarchical structure and properties of intercalated polypropylene/ clay nanocomposites. Polymer, vol.42, (2001), 9633-9640... 

The mechanism of the improvement of thermal stability in polymer nanocomposites is not fully understood. It is often stated [126-129] that enhanced thermal stabihty is due to improved barrier properties and the torturous path for volatile decomposition products, which hinders their diffusion to the surface material where they are combusted. Other mechanisms have been proposed, for example, Zhu et al. [130] recently proposed that for polypropylene-clay nanocomposites, it was the structural iron in the dispersed clay that improved thermal stability by acting as a trap for radicals at high temperatures. 

Physical Properties of the Modified Polypropylene-Clay Nanocomposites. 169... 

A nanocomposite made using modified polypropylene and Cl8-Mt is called a Polypropylene-Clay Nanocomposite (PPCN). Because clay min-... 

This section describes the mechanical characteristics, dynamic viscoelasticity characteristics, and gas permeability characteristics of a modified polypropylene-clay nanocomposite [35]. C18-Mt was used as the organophihc clay, and P01015 was used as the maleic anhydride-modified polypropylene. 

The two factors shown below affect the physical properties of a polypropylene clay nanocomposite made by compoimding polypropylene and organo-phiUc clay using modified polypropylene as a compatibihzer [16,36]. They also affect the dispersibility of sihcate layers in this nanocomposite ... 

This section describes how the dispersed state of the silicate layers in a polypropylene clay nanocomposite and the physical properties of this nanocomposite are affected by the type of clay used. Two types of clay were used in this experiment organophihc montmorillonite and organophiUc mica. 

Garcia-Lopez, D., Picazo, O., Merino, J. C., and Pastor, J. M. 2003. Polypropylene-clay nanocomposites Effect of compatibilizing agents on clay dispersion. European Polymer Journal 39 945-950. 

Ratnayake, U. N. and Haworth, B. 2006. Polypropylene-clay nanocomposites Influence of low molecular weight polar additives on intercalation and exfoliation behavior. Polymer Engineering and Science 46 1009-1015. 

The first polypropylene/clay nanocomposite made by intercalative polymerization was reported by Qi et al. Sodium montmorillonite was ion exchanged with (hexadecyl/ octadecyl)trimethylammonium, then vacuum-dried at llO C. The organoclay was ground... 

Ramazani, A. 2010. Synthesis of polypropylene/clay nanocomposites using bisupported Ziegler-Natta catalyst. Journal of Applied Polymer Science 115 308-314. 

Sun, T. and Garces, J. M. 2002. High-performance polypropylene-clay nanocomposites by in-situ polymerization with metallocene/clay catalysts. Advanced Materials 14 128-130. 

TEM micrograph of polypropylene clay nanocomposites with 2wt% of PP-b-PPG compatibilizer. (Reproduced from Mittal, V., J. Thermoplast. Compos. Mater., 22, 453, 2009. With permission from Sage Publishers.)... 

Jang, L. W., Kim, E. S., Kim, H. S., and Yoon, J.-S. 2005. Preparation and characterization of polypropylene/ clay nanocomposites with polypropylene-graft-maleic anhydride. Journal of Applied Polymer Science 98 1229-1234. 

Wang, Y., Chen, F.-B., Li, Y.-C., and Wu, K.-C. 2004. Melt processing of polypropylene/clay nanocomposites modified with maleated polypropylene compatibilizers. Composites Part B 35 111-124. 

Perrin-Sarazin, F., Ton-That, M.-T., Bureau, M. N., and Denault, J. 2005. Micro- and nano-structure in polypropylene/clay nanocomposites. Polymer 46 11624-11634. 

Kotek, J., Kebiar, I., Studenovsky, M., and Baldrian, J. 2005. Chlorosulfonated pol5q)ropylene Preparation and its applications as a coupling agent in polypropylene-clay nanocomposites. Polymer 46 4876-4881. 

---