Fundamentals of the ageing process

Summary form only given. The universal ageing mechanism is one of thermally-assisted atomic and molecular structural rearrangement via chemical and physical bond breakage. This process will be reviewed in some detail and the concept of dilatons introduced. From the associated reaction rate, various statistical criteria for ageing and ultimate failure can be deduced. The imposition of forces arising from electrical, mechanical, chemical and concentration gradients (multi-factors) will lead to changes in reaction rate and therefore in the ageing process. Under high gradients the process can become non-thermal and the ageing process catastrophic. It will be shown that free radicals and other highly active species resulting from bond-breakage as ageing proceeds can provide feedback mechanisms which will hasten the ageing process and lead to more rapid degradation