Synthesis and properties of a millable polyurethane nanocomposite based on castor oil and halloysite nanotubes

Abstract

The use of bio-based materials has recently attracted a lot of attention in the area of polymer synthesis. In this work, a bio-based millable polyurethane (MPU) based on castor oil and its nanocomposites containing a very low content of halloysite nanotubes have been successfully prepared. These MPU/HNT nanocomposites showed higher tensile strength and elongation at break compared with the pristine MPU material. The tensile strength and Young’s modulus of the MPU/HNT nanocomposites were improved by 35% and 63% by incorporating only 0.5 wt% of the HNTs, respectively, which was primarily attributed to the formation of covalent bonds between the OH groups of the HNTs and the NCO groups of 2,4-toluene diisocyanate (TDI). The nanostructure of these MPU nanocomposites was characterized by spectroscopy studies and direct microstructural analysis.