Water-assisted melt compounding of nylon-6/pristine montmorillonite nanocomposites

An exploratory pioneering study on the fabrication of nylon-6/montmorillonite (MMT) nanocomposites with the aid of water as an intercalating/exfoliating agent via melt compounding in a twin-screw extruder was conducted. Commercial nylon-6 pellets and pristine MMT powder were directly fed into the hopper of the extruder. Water was then injected into the extruder downstream. After interactions with the nylon-6 melt/pristine MMT system, water was removed from the extruder further downstream via a venting gate. As such, no third-component residual was left within the extrudates. Transmission electron microscopy micrographs showed that pristine MMT was uniformly dispersed in the nylon-6 matrix. The contact time between water and the nylon-6/pristine MMT system inside the extruder was so short that nylon-6 was subjected to very little hydrolysis, if any. The resultant nanocomposites showed higher stiffness, superior tensile strength, and improved thermal stability in comparison with their counterparts obtained without water assistance and the nylon-6/organic MMT nanocomposites. (c) 2005 Wiley Periodicals, Inc.