Nanocomposite polymers, fire

Jang, B. N., Costache, M., and Wilkie, C. A. The relationship between thermal degradation behavior of polymer and the fire retardancy of polymer/clay nanocomposites, Polymer (2005), 46, 10678-10687. 

B. Schartel, M. Bartholmai, and U. Knoll, Some comments on the main fire retardancy mechanisms in polymer nanocomposites, Polym. Adv. Technol., 2006, 17 772-777. 

Marosi, G., Keszei, S., Matko, S., and Bertalan, G. 2006. Effect of interfaces in metal hydroxide-type and intumescent flame retarded nanocomposites. In Fire and Polymers TV Materials and Concepts for Hazard Prevention, Vol. 922, eds. Wilkie, C. and Nelson, G. Washington, DC ACS, pp. 117-30. 

Lewin, M. 2003. Some comments on the modes of action of nanocomposites in the flame retardancy of polymers. Fire and Materials 27 1-7. 

Micro- to Mesoscale Testing and Modeling for Nanocomposite Polymers in Fires... 

The materials included in this chapter for illustration are nanocomposite polymers combined with intumescent commercial phosphorous fire retardants. In this chapter, different base polymers (e.g., PA6, PBT, PP, and EVA) are mentioned for illustrating the methodology but the focus will be on PA6. For the present purpose, the composition of a PA6 nanocomposite is described next to make the development of the present methodology more clear. 

The dynamic viscosity and storage modulus of the melt polymer can characterize (1) the degree of dispersity (i.e., intercalation) of the nanocomposite polymer [1,2], (2) the dripping tendency in mesoscale or large-scale fires [3,4], and (3) the structure of the char layer formed during pyrolysis in mesoscale or large-scale fires [5-7]. 

Charles A. Wilkie is currently Professor Emeritus of Chemistry at Marquette University. He received his B.S. degree from the University of Detroit and his Ph.D. in Inorganic Chemistry from Wayne State University, following which he joined Marquette University. He has been assistant, associate, and full professor and retired as the Habermarm-Pfletschinger Professor in 2009. His main areas of interest for the past several years have been polymer nanocomposites and fire retardancy. 

Keywords nanocomposite, organoelay, fire retardant polymer. 

Schartel B, Braun U, Knoll U, Bartholmai M, Goering H, Neubert D and Potschke P (2008) Mechanical, thermal, and fire behavior of bisphenol a polycarbonate/multiwall carbon nanotube nanocomposites, Polym Eng Sci 48 149-158. 

J. Zhang and C. A. Wilkie, Fire retardancy of polypropylene-metal hydroxide nanocomposite. In Fire and Polymers, A.C.S. Symposium Series 922, ed. C. Wilkie and G. Nelson (Washington, DC American Chemical Society, 2006), pp. 61-74. 

Three main mechanisms for the effects of polymer/LDH nanocomposites on fire properties involve barrier formation during combustion, melt viscosity increase, and nanodispersed LDH layers. 

These qualitative effects can be described quantitatively within the framework of percolation model of reinforcement and multifractal model of gas transport processes for nanocomposites polymer/organoclay [3, 4]. It has been supposed that two structural components are created for a barrier effect to fire spreading actually organoclay and densely packed regions on its surface with relative volume fractions (p and (p respectively. In other words, it has been supposed, that the value should be a diminishing function of the sum ((p -l-(pp. For this supposition verification let us estimate the values (p and (p The value (p is determined according to the well-known equation [5] ... 

Yang, F. Yngard, R. Nelson, G.L. Flammability of polymer-clay and polymer-silica nanocomposites. J. Fire Sci. 2005, 23(3), 209. 

Jash, P. Wilkie, C.A. Effects of surfactants on the thermal and fire properties of poly(methyl methacrylate)/clay nanocomposites. Polym. Degrad. Stab. 2005, 88 (3), 401. 

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