INTERACTIONS OF PHENOLIC RESIN ALKALINITY, MOISTURE-CONTENT, AND CUREBEHAVIOR

The results of a dynamic mechanical analysis technique (DMA), already developed for estimating the extent of residual cure of phenol-formald ehyde resol resins, depend on the moisture content of the resin. For t wo resins, different but regular relationships were found between DMA- sample moisture content and the resultant tan delta area, which is mea sured to determine residual cure of samples. Moisture content also app ears to be important for cure determinations by differential scanning calorimetry. The research reported here showed that alkali content, ex tent of precure, and relative humidity affect the equilibrium moisture content of phenol-formaldehyde resol resins.