Inclusion complex-based multifunctional polyurethane antibacterial coatings with excellent mechanical and thermal properties

Sulfonated β-cyclodextrin (CD1) combined with nanocurcumin or nanoclay was used to prepare multifunctional polyurethane (PU) coatings having antimicrobial capabilities. The combination resulted in formation of an inclusion complex which is confirmed by Raman studies and Job's plot analysis. The co-precipitation method is employed to achieve two inclusion complexes by combining CD1 with Cloisite 30B (C30B) and nanocurcumin (NC) separately. The resultant nanocomposite coating samples exhibit < 100 °C deviation at 50% weight loss from PU in heat resistance, as well as a 78% enhancement in toughness and 2.3–3 cm of zone of inhibition which is comparable to amoxicillin in its performance in resistance to bacterial growth. The advantage of absorbing such inclusion complexes into polymer coatings is the creation of multifunctionalities such as hydrophobicity, flame retardance, thermally stable and low intumescent coatings.