Measuring Vapors To Monitor the State of Cure of a Resin

A proposed noninvasive method of monitoring the cure path and the state of cure of an epoxy or other resin involves measurement of the concentration( s) of one or more compound(s) in the vaporous effluent emitted during the curing process. The method is based on the following general ideas: (1) The concentrations of the effluent compounds in the vicinity of the curing resin are approximately proportional to the instantaneous rate of curing. (2) As curing proceeds at a given temperature, subsequent decreases in the concentrations are indicative of approaching completion of cure; that is, the lower are the concentrations, the more nearly complete is the cure.