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

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