抄録
Ultrasonic properties in the MHz region were studied for a series of epoxy resins cured with methylnadic anhydride. The longitudinal and shear wave velocities in the glassy state resins decreased with crosslinking. The apparent modulus calculated from veloc ities, and longitudinal wave attenuation also showed that the elasticity in the glassy state resins vary inversely with the crosslinking density, whereas the elasticity in the rubbery resins was expected to vary directly with the crosslinking density. Those differences in elasticity between the glassy state resins and the rubbery state resins can be explained by a hindering effect of crosslinks during glass transition process.
