The Degradation Mechanisms Study of the Organoclay by Using the Nitrogen Absorption/Desorption and X-ray Diffraction

Abstract

Surfactants modified organoclays are known to undergo degradation during the melt process. In this work nitrogen absorption/desorption and X-ray diffraction were applied to study the mechanic of the degradation by employing the thermal treated commercial organoclay 93A. The 93A powder samples were heated in the Muffle furnace for 2 minutes at temperature ranged from 200 Celsius from 600 Celsius (200°C, 250°C, 300°C, 350°C and 600°C). The N2 absorption/desorption results showed the BET surface area is 10.402 m2/g, 9.455 m2/g, 14.169 m2/g, 8.860 m2/g and 9.198 m2/g respectively. The XRD results showed the d-space [001] 2θ=3.8 for all the samples (200°C -350°C) which did not change compared with the original 93A while the 600°C this unique reflection disappeared. The results indicate that the silicate clay skeletons thermal resistant ability can protect the surfactant molecules from degradation in the test temperature range low 350°C and the surfactant (which intercalated in the galleries) at the edge part of the galleries is first to degrade. High heating temperature can accelerates the vapour of the surfactants in the degradation process.