Macroradicals in poly(phenyl-p-phenylene terephthalate)

Effects of the mechanical, radiation, and thermal factors on the EPR spectr a of free radicals in poly(phenyl-p-phenylene terephthalate) were studied. The mechanical fracture and X-ray irradiation at room temperature led to th e formation of phenoxyl macroradicals. Small concentrations of these radica ls were also formed as a result of thermal degradation of the polymer durin g jet drawing from melt. Thermal treatment led to the loss of the initial r adicals and the formation of more stable ones, presumably representing quin oid fans of phenylphenoxyl macroradicals. The hyperfine interaction paramet ers of radicals were determined from the ENDOR spectra.