Electron spin resonance of heattreated phenol-formaldehyde resins

✍ Scribed by S Toyoda; S Sugawara; T Furuta; H Honda

• Publisher: Elsevier Science
• Year: 1970
• Tongue: English
• Weight: 380 KB
• Volume: 8
• Category: Article
• ISSN: 0008-6223
• DOI: 10.1016/0008-6223(70)90008-4

✦ Synopsis

Studies of the electron spin resonance in dependence on heattreatment temperature (HTT) were carried out for phenol-formaldehyde resin (PF), 3methylphenol-formaldehyde resin (SMPF) and 3,5-dimethylphenol-formaldehyde resin (3, SDMPF) prepared with aqueous solution of ammonia as catalyst. The peak-topeak line width and the spin center concentration for these three kinds of resin carbons show a normal behaviour up to about 1000°C. The g-value for 3, 5DMPF is about equal to that of the free spin up to about 14OO"C, above which it increases with HTT, whereas that for 3MPF and PF remains about equal to that of the free spin up to about 2600°C. The rate of change of peak-to-peak line width in the range from about 1400°C to about 2400°C increases in the order of PF, 3MPF and 3,5DMPF. This coincides with the order of the ease of graphitization, as shown by the studies of specific gravity, diamagnetic susceptibility, electrical resistance, and measurements of crystallite size L,& and L,.