Researchers developed a method to prepare solvent free castor oil (CO) based polyurethane (PU) adhesives with different ratios of CO and hexamethylene diisocyanate (HMDI). The new method is based on synthesis by promoting the reaction between castor oil and HMDI, at room conditions, and by varying the CO/HMDI weight ratio. Since these adhesives are cured at room temperature, there is no need any external stimuli such as heat or irradiation treatment. The mechanical properties, adhesion energy in metal–metal contact, structure–mechanical property relationship were explored by different techniques. The results showed that adhesion of these solvent free bio-based adhesives to different substrates such as wood, paper, textile, and metal is promising in different industrial and commercial applications.

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This article is published in Industrial Crops and Products, Volume 121, 1 October 2018, Pages 90-98.