Novel polyether polyurethane/clay nanocomposites synthesized with organicly modified montmorillonite as chain extenders

A kind of novel polyether polyurethane (PU) /clay nanocomposite was synthesized using poly(tetramethylene glycol), 4,4'-diphenylmethane diisocyanate (MDI), 1,6-hexamethylenediamine, and modified Na+-montmorillonite (MMT). Here, organicly modified MMT (O-MMT) was formed by applying 1,6-hexamethylenediamine as a swelling agent to treat the Na+-MMT. The X-ray analysis showed that exfoliation occurred for the higher O-MMT content (40 wt %) in the polymer matrix. The mechanical analysis indicated that, when the O-MMT was used as a chain extender to replace a part. of the 1,2-diaminopropane to form PU/clay nanocomposites, the strength and strain at break of the polymer was enhanced when increasing the content of O-MMT in the matrix. When the O-MMT content reached about 5%, the tensile strength and elongation at break were over 2 times that of the pure PU. The thermal stability and the glass transition of the O-MMT/PU nanocomposites also increased with increasing O-MMT content. (c) 2005 Wiley Periodicals, Inc.