Strain rate-induced phase transitions in an impact-hardening polymer composite

An impact-hardening polymer composite that is promising as a protective equipment material for its excellent performance and comfortable characteristics is shown. Falling weight impact experiments are performed to characterize its protective behavior, which is realized by absorbing energy and resisting deformation. From the mechanical tests in different strain rate, it is seen to undergo transitions from a viscous-liquid behavior to a rubbery behavior, then to a glassy behavior. These phase transition are found to be essential for their practical applications in the energy absorption and the deformation resistance.