Polymer/layered clay nanocomposites: 2 polyurethane nanocomposites

A kind of novel polyurethane/Na+-montmorillonite nanocomposites has been sy nthesised using modified 4,4'-di-phenymethylate diisocyanate (M-MDI), modif ied polyether polyol (MPP) and Na+-montmorillonite (layered clay). Here, MP P was used as a swelling agent to treat the layered clay. Experimental resu lts indicated that with increasing the amount of layered clay, the strength and strain-at-break increased. The storage modulus below the glass transit ion temperature of the soft segments in the polyurethane was increased by m ore than 350%. With increased loading of layered clay, the thermal conducti vity decreased slightly rather than increased. This finding will provide va luable information for polyurethane industry. (C) 2001 Published by Elsevie r Science Ltd.