Preparation and properties of in‐situ polymerized polyurethane/stearate intercalated layer double hydroxide nanocomposites

The present work deals with the effect of stearate intercalated layered double hydroxide (St‐LDH) loadings on the morphological, mechanical, thermal, adhesive and flame retardant properties of polyurethane (PU)/St‐LDH nanocomposites prepared by the in situ polymerization method. X‐ray diffraction and transmission electron microscopy studies confirmed that exfoliation takes place at 3 wt% loading followed by intercalation at higher filler loadings in the PU matrix. The exfoliated structure has been further verified by atomic force microscopy. The measurements of stress‐strain, thermogravimetric analysis, dynamic mechanical analysis, lap shear strength and peel strength analysis showed that the nanocomposites containing 3 wt% St‐LDH exhibit excellent improvement in tensile strength ( ca 175%) and log storage modulus ( ca 14%), while PU/St‐LDH (5 wt%) possesses optimum improvement in glass transition temperature ( ca 6 °C), lap shear strength (200%) and peel strength (130%) over neat PU. In addition, the gradual improvements in limiting oxygen index value with St‐LDH loading indicated the higher effectiveness in providing better barrier properties as well as better flame retardant behavior.