NATURE OF ADHESIVE BONDING VIA INTERCHAIN TRANSESTERIFICATION REACTIONS (ITR)

Secondary ion mass spectrometry (SIMS) was used to determine the natur e of the adhesive bonding which occurs through interchain transesterif ication (ITR) in thermosetting polyester materials (TS) and in liquid crystalline polyester polymers (LCP). An all aromatic copolyester ther moset was prepared as a deuterated and undeuterated film. These films were cured and then consolidated using heat and pressure to form a goo d adhesive bond. SIMS produced no direct observation of interdiffusion indicating that the length scale over which it occurred must be less than 500 Angstrom (the resolution of the technique). A similar set of experiments was carried out using a deuterated and non-deuterated film of a liquid crystalline copolyester (LCP) consisting of 73/27 p-hydro xybenzoic acid and 6-hydroxy-2-naphthoic acid. In this case, the deute rated units diffused throughout the entire undeuterated films within l ess than one hour at 280 degrees C.