Plant oil derived epoxy thermosets
Epoxy thermosets are used as adhesives and coatings in electronics, appliances and aircraft. But most of them are not environmentally friendly. Epoxidised plant oil thermosets are usually weak and easily break. Researchers wanted to fabricate a biobased epoxidised plant oil thermoset.
They synthesised dicarboxyl-terminated polyamide1010 (Nyl) oligomers from castor oil derived monomers, i.e., sebacic acid and decamethylene diamine, and used Nyl to cure epoxidised soybean oil (ESO) to fabricate all plant oil derived epoxy thermoset through a catalyst-free curing method.
Excellent comprehensive properties
Chemorheological study indicated that the curing rate decreases with increasing Nyl chain length. The cross-link density of the epoxy thermoset decreases while the crystallisation enhances with increasing Nyl chain length, which results in drastic enhancement in tensile strength, Young’s modulus, and elongation at break of the resultant thermosets, enabling those parameters to enhance by up to 59, 145, and 18 times, respectively, compared to sebacic acid cured ESO thermoset. The melting temperature and thus the heat resistance of the thermosets are also enhanced obviously with increasing Nyl chain length. In addition, the thermosets show good durability and excellent thermal stability. With excellent comprehensive properties, the all plant oil derived epoxy thermosets could find some structural applications other than adhesives and coatings.
The study is published in: Macromolecules, 2017, 50 (15), pp 5729-5738.
