Study of the Thermal Stability, Degradation Mechanisms and Properties of Polymer/Organically Modified Layered Silicate Nanocomposites

摘要

PS-MMT nanocomposites were prepared via suspension free radical polymerization of styrene in the dispersed organo-MMT. The results of XRD and TEM indicated that exfoliated nanocomposites were achieved. The effect of surfactants on the properties of then synthesized nanocomposites was studied. It is found that PS MMT nanocomposite with 5% wt% of organo-MMT gave the greatest improvement in the thermal stability, and PS-MMT nanocomposites with 7.5% of organo- MMT showed the greatest improvement in mechanical properties, comparing with that of pure PS in our experimental conditions. The alkyl chain length of surfactant used in fabricating organo-MMT affects the synthesized PS nanocomposites, the longer the alkyl chain length that the surfactant possesses, the higher glass transition temperature PS nanocomposite. It is found that the organoclay in the nanocomposites seems to play a dual role: (a) as nanofiller leading to the increase of storage modulus and (b) as plasticizer leading to the decrease of storage modulus.