TY - GEN
T1 - Transition metal ion modified organoclays as fire retardant fillers for polymer nanocomposites
AU - Nawani, Pranav
AU - Desai, Priya
AU - Gelfer, Mikhail Y.
AU - Hsiao, Benjamin S.
AU - Gilman, Jeffrey W.
PY - 2007
Y1 - 2007
N2 - In this study, transition metal ion (TMI) modified organoclays and their polymer nanocomposites with ethylene-vinyl acetate (EVA) were investigated for their morphology, thermal and flame retardant properties, using scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo gravimetric analysis (TGA), limited oxygen index (LOI) and standard UL-94 techniques. The content of TMI in modified clays was characterized by elemental analysis and the results were found to be close to the limiting value of cation exchange capacity (CEC). Scanning electron microscopy confirmed that transition metal ions were located between the mineral layers instead of being adsorbed on the surface of clay particles. TGA results of TMI modified clays indicated that the TMI treatment of organoclays could significantly increase the thermal stability and hence these can be used as flame retardant fillers. TGA measurements also revealed that the presence of TMI increased the onset temperature of structural degradation. The higher thermal stability of TMImodified organoclays can be attributed to the change in the thermal degradation mechanism, including the decrease in the yield of volatile products and the enhanced formation of char facilitated by catalytically active TMI. The corresponding TMImodified clay nanocomposites exhibited significantly improved thermal stability and fire retardation properties, but similar morphology (i.e., an intercalated-exfoliated structure). The improved fire retardation properties can be explained by the enhanced carbonaceous char formation during combustion.
AB - In this study, transition metal ion (TMI) modified organoclays and their polymer nanocomposites with ethylene-vinyl acetate (EVA) were investigated for their morphology, thermal and flame retardant properties, using scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo gravimetric analysis (TGA), limited oxygen index (LOI) and standard UL-94 techniques. The content of TMI in modified clays was characterized by elemental analysis and the results were found to be close to the limiting value of cation exchange capacity (CEC). Scanning electron microscopy confirmed that transition metal ions were located between the mineral layers instead of being adsorbed on the surface of clay particles. TGA results of TMI modified clays indicated that the TMI treatment of organoclays could significantly increase the thermal stability and hence these can be used as flame retardant fillers. TGA measurements also revealed that the presence of TMI increased the onset temperature of structural degradation. The higher thermal stability of TMImodified organoclays can be attributed to the change in the thermal degradation mechanism, including the decrease in the yield of volatile products and the enhanced formation of char facilitated by catalytically active TMI. The corresponding TMImodified clay nanocomposites exhibited significantly improved thermal stability and fire retardation properties, but similar morphology (i.e., an intercalated-exfoliated structure). The improved fire retardation properties can be explained by the enhanced carbonaceous char formation during combustion.
UR - https://www.scopus.com/pages/publications/84893280730
M3 - Conference contribution
AN - SCOPUS:84893280730
SN - 1596233214
SN - 9781596233218
T3 - Proceedings of the 18th Annual Conference on Recent Advances in Flame Retardancy of Polymeric Materials
SP - 205
EP - 217
BT - Proceedings of the 18th Annual Conference on Recent Advances in Flame Retardancy of Polymeric Materials
T2 - 18th Annual BCC Research Conference on Recent Advances in Flame Retardancy of Polymeric Materials 2007
Y2 - 21 May 2007 through 23 May 2007
ER -