Thermal behaviour of poly(propylene) layered silicate nanocomposites

The thermal degradation behaviour of nanocomposites based upon poly(propyle ne)/organoclay, modified with protonated octadecyl amine (C18) in compariso n to that of non-exfoliated microcomposites based upon organoclay, modified with protonated butyl amine (C4), was studied by thermogravimetry. In the case of the nanocomposite, the temperature at which volatilisation occurs i ncreases as compared of the microcomposite. Moreover, the thermal oxidation process of the polymer is strongly slowed down in the nanocomposite with h igh char yield both by a physical barrier effect, enhanced by ablative reas sembling of the silicate, and by a chemical catalytic action due to the sil icate and to the strongly acid sites created by thermal decomposition of th e protonated amine silicate modifier.