Hydrolytic deterioration of polyimide insulation on naval aircraft wiring

Experimental and theoretical work carried out on the hydrolytic deterioration of polyimide insulation on naval aircraft wiring is reviewed. Initial results are consistent with literature reports that mechanical strain (from bending and stretching the wires) has a strong influence on the hydrolysis reaction rate, and therefore the complex model for life prediction must include a multifactor modification of the Arrhenius Model. The critical technical issue is then one of developing the theoretical formula for determining the deterioration rate from the combination of fundamental kinetics and thermodynamic principles needed to express the multifactor stress effects on the commonly utilized Arrhenius formula.<>