Development of sustainable polyols with high bio-renewable content and their applications in thermoset coatings

Abstract In recent years, bio-renewable based materials have been increasingly explored as a promising replacement for petroleum-based ones used as building blocks for polymers. This trend is mainly driven by the increasing awareness and directives for the sustainable development of polymeric materials, including coatings. The lower carbon footprint compared to their petroleum counterparts and depleting known resources of petroleum makes bio-renewable materials very important for future development. However, it is very important to meticulously design polymers based on bio-renewable building blocks by leveraging their unique chemistry and functionality, to meet the demanding requirements of the final products at acceptable costs. In the present work, by combining unique features and functionalities of two low-cost commercial commodity bio-renewable based materials - Epoxidized soybean oil (ESO) and rosin – polymeric polyols with bio-renewable content > 78 % by weight have been successfully developed. A series of single-component melamine-formaldehyde (MF) cured thermoset coatings have been then formulated and evaluated. Some of the prepared coatings demonstrated excellent adhesion (5B), high MEK-Double-Rubs (100–200), high gloss @ 60° (>80), and promising flexibility and impact resistance properties (140−160 lb.in). The outcome of this study clearly demonstrates the suitability of these polyols as primary components of sustainable industrial coatings.