The effect of microstructure on the rate-dependent stress–strain behavior of poly(urethane urea) elastomers

摘要: Segmented poly(urethane urea) materials (PUUs) exhibit versatile mechanical properties and have drawn great interest due to their potential for protection against projectile impacts blast loadings. To optimize the performance of PUUs various high rate applications, specific features behavior be suitably tailored by altering microstructure. Hence micromechanisms governing must identified, understood leveraged. In this study, effects varying microstructure on rate-dependent were examined select PUU materials. As expected, increasing hard segment content increased stiffness flow stress levels. Interestingly, it was observed that promoting phase mixing among soft domains material greatly enhanced its stiffening strain hardening behavior. These insights can help design articles manifest improved protective abilities under impact, while maintaining flexibility during normal use. The applications such are extensive, including face masks goggles, which require excellent folding/un-folding capabilities, also providing superior impact resistance.