| Popis: |
We report on a series of impact recovery experiments performed on organic samples. Acrylamide was loaded to peak stresses of 4.8 and 6.7 GPa in a copper capsule using an air-driven projectile. No polyacrylamide was formed in these impact experiments. ESR studies reveal ~ 1 ppm free radicals, which are stable in the acrylamide lattice. Upon solution in tetrahydrofuran (THF), these radicals become mobile, resulting in polymer formation, a reaction not seen in unshocked acrylamide THF solutions. Recovery experiments were also carried out on anthracene and 9-cyanoanthracene (9-CA) in the stress range 1.8-4.0 GPa. The residual radical density in the 9-CA was roughly 10 times that in the anthracene. A systematic relation between peak stress and formation of specific radicals was observed. |
