Fig. 3: Characterization of mechanical properties of the PUA-PEGDA copolymers.

a Stress–strain curves of PUA and PUA–PEGDA copolymer films (5, 10, and 15 wt%) determined from a standard tensile test at a displacement rate of 3.33 mm s−1. The inset image shows magnification at low tensile strains between 0 and 200%. Loading and unloading cyclic tests performed on b PUA, c PUA–PEGDA-5, d PUA–PEGDA-10, and e PUA–PEGDA-15 at a strain rate of 1 mm s−1 for 30 cycles, showing the reduction in hysteresis loss