Abstract: | Electron paramagnetic resonance measurements of the number of free radicals formed during cutting and grinding of polymers are described. It was found in the semicrystalline polymers studied that below the glassy transition temperature that the number of free radicals formed is about 2 × 1013/cm2 of surface formed. It is proposed that this number results from the crack progressing selectively through the glassy regions about more ordered regions in the polymers. |