Accession Number : ADA306084

Title :   Correlation of Electrical Conductivity and Radiation-Induced Free Radical Concentration in Poly(Ethylene Terephthalate) and Related Compounds,

Corporate Author : RESEARCH TRIANGLE INST RESEARCH TRIANGLE PARK NC

Personal Author(s) : Monteith, L. K. ; Turner, D. T. ; Ballard, L. F.

PDF Url : ADA306084

Report Date : 1968

Pagination or Media Count : 68

Abstract : This report describes a research effort concerning the electronic processes in irradiated poly(ethylene terephthalate), PET, and two model compounds. The radical concentration in PET is shown to build up continuously as the gamma-dose or UV light exposure is increased. Three different radicals are identified by ESR spectra. The relative concentration of each radical depends upon the degree of crystallinity of the sample. The optical absorption near 3100 A and the electrical conductivity of irradiated samples are tied directly to the radical concentration. This is demonstrated by observing the rate of buildup of each effect and the kinetics of radical decay and conductivity decay at various temperatures. The quenching effect of oxygen is also shown to be similar for radical concentration, optical absorption, and electrical conductivity. Carrier mobilities are measured for PET and molecular crystals of dimethyl terephthalate and dibenzoate ester of ethylene glycol. The mobility of the molecular crystals is observed to decrease significantly after exposure to gamma-rays. Bulk and surface polarization effects are observed to play a dominant role in transient electronic behavior. jg p2

Descriptors :   *RADIATION, *ELECTRICAL CONDUCTIVITY, *CORRELATION, *FREE RADICALS, *POLYETHYLENE TEREPHTHALATE, TRANSIENTS, ELECTRONICS, OPTICAL PROPERTIES, POLARIZATION, ULTRAVIOLET RADIATION, EXPOSURE(GENERAL), METHYL RADICALS, LIGHT, CRYSTALS, QUENCHING, OXYGEN, SURFACE PROPERTIES, RADIATION ABSORPTION, SAMPLING, MOLECULAR STRUCTURE, KINETICS, IRRADIATION, ESTERS, PHTHALATES, DECAY, CARRIER MOBILITY, ETHYLENE GLYCOL, BULK SEMICONDUCTORS.

Subject Categories : Polymer Chemistry
      Physical Chemistry
      Radiation and Nuclear Chemistry
      Electricity and Magnetism

Distribution Statement : APPROVED FOR PUBLIC RELEASE