The purpose of this research overall is the manufacture of polyurethane nanocomposite from castor oil with the addition of montmorillonite nanoparticles as coating material. This study consists of several stages, the manufacture of montmorillonite nanoparticles (MMT), the process of forming polyols from castor oil by epoxidation and hydroxylation reactions with catalysts. The manufacture of polyurethanes (PU) by reacting polyols from castor oil and organic montmorillonite nanoparticles was then characterized and applied to polyurethane nanocomposites as coating materials. Organic montmorillonite nanoparticles are made by an intercalation process with cetyl trimetyl ammonium bromide (CTAB). Polyurethane nanocomposite was prepared by adding organic montmorillonite nanoparticles in polyols before being mixed with toluene diisocyanate. The effectiveness of polyurethane nanocomposites as heat-resistant coatings was determined by thermal properties with thermo gravimetric analysis (TGA) equipment, then the adhesive strength was tested and the morphological properties of the material coating. The manufacture of polyurethane nanocomposite from castor oil as a film coating is applied to material and characterization.