Morphology, Microhardness, and Flammability of Compatibilized Polyethylene/Clay Nanocomposites

摘要

Morphology, thermal properties, and microhardness of ethylene-glycidyl methacrylate copolymer (EGMA)/clay and ethylene-acrylic ester-glycidyl methacrylate terpolymer (EAGMA)/clay nanocomposites with different clay concentrations have been studied. The results have shown that EGMA and EAGMA are highly compatible with the organoclays Cloisite ®20A (CI20A) and Cloisite ®3oB (CI30B). Intercalated structures are formed in the whole range of CI20A loadings investigated, whereas partial degradation of the CI30B organoclay was observed. The thermal characteristics and microhardness of EGMA/clay nanocomposites suggest that the filler dispersion deteriorates at high concentration. The concentrated EGMA/CI20A nanocomposites have been used as masterbatches to prepare ternary high density polyethylene (HDPE)/CI20A and low density polyethylene (LDPE)/CI20A nanocomposites. Diffractometric characterization and scanning electron microscopy observations of these materials have shown that the intercalated structure of the starting EGMA/CI20A masterbatches is preserved after dilution with the polyolefins. The results suggest that the silicate platelets remain localized within the EGMA droplets in the diluted nanocomposites. The latter display improved microhardness, whereas the mechanical properties, including elongation at break, are comparable with those of the neat polyolefins. Considerable enhancement of the flame retardant properties has been observed for the ternary nanocomposites. [PUBLICATION ABSTRACT]