Cashew nutshell liquid (CNSL) is a non-edible, bio-based material commonly used as a building block for various resins, hardeners, and modifiers in the adhesives, coatings, and composites industries. A high-purity cardanol, 3-pentadeca-dienyl-phenol, derived from the bio-oil CNSL has been employed to replace nonyl phenol (NP) in various applications, including isocyanate blocking.