International Journal of Materials and Chemistry 2017, 7(1): 14-19 DOI: 10.5923/j.ijmc.20170701.03 Synthesis and Application of Polylactic Acid/Kaolin Nanocomposite as a Flame Retardant in Flexible Polyurethane Foam Rifkatu D. Kambel 1 , Buba A. Aliyu 2 , Jeffery T. Barminas 2 , Ayodele Akinterinwa 2,* 1 Department of Chemistry Gombe State University, Nigeria 2 Department of Chemistry, Moddibo Adama University of Technology Yola, Nigeria Abstract Polyurethane foam is flammable. Incorporating flame retardants in the material minimize this property and hence combustion susceptibility. Here, we developed a flame retardant as we synthesis a nanocomposite from polylactic acid (PLA) and kaolin. This was incorporate into flexible polyurethane foam. FTIR of incorporated foam shows peaks at 1099.26 cm -1 and 1267.51 cm -1 attributable to oxysilicane (Si-O-) and organosilicone (Si-C) respectively, suggesting an interaction between the foam and the nanocomposite. SEM was used to present the morphology of the foam formed, while the effect of the nanocomposite on the flame characteristics of polyurethane was studied at varying amount for optimum effect. The results showed that the flame propagation rate, flame duration, and after glow of foams formed decrease while ignition time and char formation increases with increase in the amount of PLA/kaolin nanocomposite incorporated. These results potentially presents PLA/kaolin nanocomposite as a good flame retardant for flexible polyurethane foam. Keywords Polylactic acid (PLA), Kaolin, Nanocomposite, Flame retardant, Polyurethane foam 1. Introduction Loss of materials due to fire disaster may be efficiently checked if the combustion affinity of the materials can be suppressed to the barest minimum. Prior to burning, the surface of a material must receive a significant amount of heat (Onuegbu and Ejimofor, 2011). Polymers on exposure to heat undergo thermal degradation to yield volatile combustible products which interact with atmospheric oxygen, initiating and propagating flame (Camino et al., 1993). The easiest and cheapest way to control or reduce the flammability of polymer is by incorporating flame-resistant additives (Eboatu et al., 1996). Polyurethanes are versatile polymeric material with various functional properties such as; excellent abrasion resistance, high toughness, chemical resistance, and low film-forming temperatures. They have also been used in coating, foam-making, adhesives, composites etc. (Chaoqun, 2014). In recent years, flame retardants containing melamine and halophosphate have been developed to retard the flammability of polyurethane (Dennis et al., 2013). During thermal decomposition, halophosphate breaks down to releases chlorine molecules which combine with the highly * Corresponding author: ayoterinwa@yahoo.com (Ayodele Akinterinwa) Published online at http://journal.sapub.org/ijmc Copyright © 2017 Scientific & Academic Publishing. All Rights Reserved reactive radicals released by the foam to form non-volatile inactive molecules that inhibit the fire (Dennis et al, 2013). Ahmadreza and Zahed, (2012) reported that expandable graphite has been used in an effort to create an environmentally-friendly flame retardant system for rigid polyurethane foams. Expandable graphite is an intercalated graphite compound in which some oxidants like sulfuric acid and potassium permanganate are inserted between the carbon layers of graphite. Phosphonamides additives have drawn much attention in the last decade as a result of their excellent flame retardant properties (Ahmadreza and Zahed, 2012). These compounds predominantly act through a gas phase-inhibition mechanism during combustion. They decompose and release low molecular weight phosphorus containing fragments that are able to recombine with H + and OH - radicals and thus interrupt the combustion process (Ahmadreza and Zahed, 2012). Polymer-layered silicate nanocomposites have also been recently reported to offer great potentials, providing superior properties, when compared to pure polymers and conventional filled composites (Brehme et al., 2011). These properties include high dimensional stability, high heat deflection temperature, reduced gas permeability, improved flame retardancy, and enhanced mechanical properties (Brehme et al., 2011; Xia et al., 2005). Effects of various organoclays of nano sizes on the thermo mechanical properties and morphology of polyurethane foam have been investigated (Ganiyu et al., 2010). This has shown that most clay layers were dispersed