Shock dissipation through epoxy materials with engineered internal domains, glass transitions, and isomers*

Using a new synthesis, the structure of a phase-separating epoxy material can be tuned to consist of periodic internal soft and hard domains, ranging in length scales from nano- to micro-scale dimensions. Tuning these structures also results in materials with a broad distribution of glass transitions. In this work we showed an increase in interfaces between hard and soft domains, on the scale of 100's of nanometers, and a broad glass transition dissipates the shock energy more than domains on the micron scale with a narrow glass transition. The dominating mechanism is discussed. We also showed there is no shock dissipation mechanism through an epoxy with a negative coefficient for thermal expansion due to isomeric rearrangement at high temperature.