High Resilience and Elongation of Linear Polyurethane Acrylate Modified with Polyetheramines

Solvent-free polyurethane acrylate (PUA) by UV-cured process generally has low molecular weight, and thus shows weak mechanical properties, which limited its application. Herein, five kinds of linear polyetheramine modified polyurethane acrylates (PUPEA) were prepared using polyetheramine (PEA) instead of partial acrylic monomers as capping agents at the end of the polyurethane to improve the resilience and elongation. Structures of PUPEA were characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy (¹H NMR). Mechanical properties, hydrophobicity and thermodynamic properties of the obtained PUPEA were investigated and compared with those of conventional PUA. The results show that the semi-capping polyurethane with PEA instead of HEA can significantly improve the resilience and flexibility, specially, the flexibility increases about thrice to fourfold higher than those of PUA. Moreover, PUPEAs provide the self-healing properties and self-adhesive properties, while the conventional PUA does not have. Therefore, the introduction of PEA can effectively regulate the properties of PUA, which expands the application of UV-curable polyurethane elastomers in flexible electronic sensors.