Effect of Epoxy Modifier on Flame Retardancy and Rheological Behaviour of ABS/Montmorillonite Composites

Abstract

Acrylonitrile–butadiene–styrene resin (ABS) composites were prepared by melt intercalation of organically modified montmorillonite (OMMT) with or without pre-treatment by liquid epoxy resin. The morphology, flame retardancy and rheological properties of the composites were studied. Morphology observation using X-ray diffractometer (XRD) and transmission electron microscopy (TEM) reveals that the processing conditions used for epoxy modification have a great influence on the morphology and structure of the composites. With the direct addition of epoxy, the ABS/MMT composite has an intercalated structure; while with the pre-treatment of MMT with epoxy, the composite has an exfoliated structure in which MMT is well dispersed at nano-scale. Cone analysis results show that those composites with an intercalated structure have a slightly lower heat release rate (HRR) than the ones with an exfoliated structure, indicating a slight difference in flame retardancy between the two. The viscoelastic behaviour of the composites was measured by using a parallel plate rheometer. In the low frequency zone, the composites with an exfoliated structure exhibited a distinct storage modulus plateau and a solid-like response, and they had a higher storage modulus and viscosity than the ones with an intercalated structure.