NOVEL DIAGNOSIS OF THERMAL DETERIORATION FOR ORGANIC INSULATING RESINS BY OPTICAL LOSS ANALYSIS

We proposed an ''optical loss analysis'' as a novel nondestructive dia gnosis for the thermal deterioration of insulating resins. Using an al kyd resin film, the optical absorption loss per unit optical path leng th and the glass transition temperature (T-g,T-DMA) by dynamic mechani cal analysis were measured during heating tests. At longer heating tim es, values of the optical absorption loss and the T-g,T-DMA increased concurrently. By rescaling the heating time as a reduced time, a maste r curve of the deterioration for the resin was obtained. Consequently, when thermal stress is the main cause of the deterioration, one can e stimate the degree of deterioration and theoretically the residual liv es of resins using this optical loss analysis.