Aluminum Trihydroxide (ATH) as a Filler for Polymer Composites: Comparative Evaluation of Precipitation and Grinding on Thermal Stability and Dehydration Kinetics

摘要

Aluminum trihydroxide (ATH), Al(OH)_3, is a preferred filler for a variety of thermoset and thermoplastic resin composite systems, owing largely to its flame retardant and smoke suppressant properties. The fire retardant properties of ATH arise from the high ehat capacity of ATH and its endothermic release of water at elevated temperatures (> 220-230 deg C). This latter property is a double edged sword however, given that polymer processes such as extrusion and lamination often subject polymer-filler systems to elevated temperatures for short periods of time. Filler thermal stability is an important concern for these applications since filler decomposition (release of bound hydroxyls or physisorbed water) initiated by manufacturing process conditions could increase entrained free moisture, giving rise to processign problems, apperance or surface defects in the final product and/or possible degradation of end use performance properties.