Curing kinetics and mechanical properties of resol type of phenolic resin were studied for various isocuring temperatures and times. From the data of conversion and isocuring time, reaction rate constants at each isocuring temperature were determined and increased with temperature. Byproducts such as water was rapidly produced during the curing reaction at 210℃. From Arrhenius-type ananlysis, the activation energy and frequency factor for the curing were determined as 25.8kcal/mol and $4.44×10^{11}min^{-1}$. As a result, the conversion increased with the increase in isocuring time and temperature, and thus the crosslink density also increased.
By the results of mechanical test, tensile strength, tensile modulus and toughness increased at 150~180℃. In the relationship between crosslink density and mechanical properties, a master curve could be obtained between 150℃ and 180℃, but not 210℃ at which the water vapor was generated very rapidly. It was thought that the mechanical properties of specimens made at 210℃ went down and started to deviate from the master curve because of the effect of water. From the scanning electron microscope experiment, it was found that the water rapidly produced in the curing reaction at high isocuring temperature much influenced the mechanical properties of resol type of phenolic resin. At 210℃ the material had the higher modulus than at 150~180℃ but lower tensile strength and toughness. Consequently, it is suggested to process according to the cascade-type curing procedure at 150 and 180℃.
