New biobased polyurethane coatings
A new study decribes polyurethane coatings with fast self-healing and tunable mechanical properties derived from curcumin and castor oil.
![Global energy demand and oil prices have led to the use of bio-based and potentially low-cost materials derived from renewable resources as an alternative source for polymer production. Photo credit: Alexander Ruiz - stock.adobe.com (symbol image).](https://www.european-coatings.com/wp-content/uploads/2023/11/Castor-Rizinus-Oil-Quelle-Alexander-Ruiz-stock3adobecom-805x0-c-default.jpg)
Biobased thermosetting polymers have attracted interest owing to their renewable source materials, long service life, and properties comparable to those of petroleum-based materials. In a new work, a biobased polyurethane coating was constructed using curcumin dioxime (CD), castor oil (CO), and isophorone diisocyanate (IPDI) to fulfill these features. The biobased CD monomer was prepared using curcumin and hydroxylamine hydrochloride.
Tunable mechanical properties.
To investigate the correlation between the mechanical properties and self-healing performance, a series of polyurethane coatings were fabricated by varying the ratio of CO to CD. The results showed that the crosslinking density, glass transition temperature, and Young modulus of these coatings increased with the decrease in the ratio of CO to CD, leading to tunable mechanical properties. Besides, all coatings demonstrated self-healing efficiency higher than 71 % within 1 min at 90 °C, and some of them even reached >90 % after 8 min.
The study has been published in Progress in Organic Coatings, Volume 183, October 2023.
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