【Objectives】Montmorillonite (MMT) is a kind of clay mineral having accumulation texture of nanosilicate sheets, so it has excellent mechanical, thermal and gas barrier properties. Three organic ion exchangers were tested in this paper in order to make MMT fully dispersed in polyurethane (PU) matrix, and then used for preparing polyurethane/montmorillonite (PU/MMT) composite materials with excellent mechanical and controlled-release properties.【Methods】Three organic modifiers, octadecyl trimethyl ammonium ammoniate (SA1), dodecyl dihydroxyet...