Eco-friendly polyurethane coatings from cottonseed and karanja oil

A series of new polyester polyols has been synthesized by the condensation reaction of epoxidized vegetable oil and poly(ethylene glycol) (PEG). Vegetable oils obtained from natural resources namely, karanja (Pongamia glabra) and cottonseed (Gossypium arboreum) were epoxidized by an eco-friendly process and further used for the preparation of polyols using PEG. The molecular weight of PEG was varied from 200 to 600 g/mol, The polyester polyols obtained were characterized by end group and spectral analysis. Eco-friendly polyurethane coatings were obtained from the synthesized polyester polyols using dipentene, a green solvent instead of xylene as a conventionally used solvent. The resultant polyurethanes were characterized by different physicochemical and thermal properties. The coating properties namely, gloss, hardness, impact resistance, adhesion, and flexibility were also evaluated and found to be useful for industrial coatings. (C) 2015 Elsevier B.V. All rights reserved.