Polymer/layered clay nanocomposites: 2 polyurethane nanocomposites

A kind of novel polyurethane/Na+-montmorillonite nanocomposites has been synthesised using modified 4,4'-di-phenymethylate diisocyanate (M-MDI), modified polyether polyol (MPP) and Na+-montmorillonite (layered clay). Here, MPP was used as a swelling agent to treat the layered clay. Experimental results indicated that with increasing the amount of layered clay, the strength and strain-at-break increased. The storage modulus below the glass transition temperature of the soft segments in the polyurethane was increased by more than 350%. With increased loading of layered clay, the thermal conductivity decreased slightly rather than increased. This finding will provide valuable information for polyurethane industry. (C) 2001 Published by Elsevier Science Ltd.