ONLINE REMOTE MONITORING OF THERMOSET RESIN CURE USING NEAR-INFRARED EXTERNAL REFLECTION SPECTROSCOPY

Near-infrared (NIR) external reflection spectroscopy is proposed as an alternate technique for on-line remote monitoring of thermoset resin cure reactions. External reflection spectroscopy is a non-destructive sampling technique requiring no sample preparation. Therefore, it has great potential for polymer reaction monitoring. External reflection s ensors can be operated in both reflection-absorption (RA) or diffuse r eflection modes (DR), depending on the nature of the samples. In this paper; the cure reactions of three thermosetting resin systems (epoxy resin/amine, BMI and BMI/amine, and epoxy resin/amine/Kevlar(R) compos ite) were monitored on-line by NIR external reflection spectroscopy us ing a remote fiber optic probe. Absorption bands suitable for monitori ng the above cure reactions are discussed in detail, thus establishing the feasibility of on-line remote reaction monitoring using these tec hniques.