PREPARATION AND PROPERTIES OF ORGANO-MODIFIER FREE PET/MMT NANO COMPOSITES VIA MONOMER INTERCALATION AND IN SITU POLYMERIZATION

In order to prevent the properties, especially transparency, color and health security, of PET/clay nanocomposites from being deteriorated due to the thermal degradation of clay organo-modifer, we had directly modified sodium montmorillonite (Na+-MMT) with PET's monomer, bis (hydroxyethyl) terephthalate (BHET) which had a degradation temperature higher than 400°C, and successfully prepared the hybrids via in situ polymerization. Nanodispersion of clay and the intercalated morphology were determined, and compared with PET/Na+-MMT hybirds in which Na+-MMT was directly added without any treatment. Improved mechanical properties and Tg were observed for the prepared PET/ BHET-modified clay composites. More importantly, the film produced from the composites had the same transparency as that of pure PET even when 2 wt% of clay was added. Non-isothermal and isothermal crystallization experiments showed a very good neculation capability of the nano-dispersed clay, particularly at higher crystallization temperatures. Copyright © 2009 John Wiley & Sons, Ltd.