Shelf-life of polyfurfuryl alcohol resin: an accelerated rheokinetics study

摘要

Thermosetting resins like polyfurfuryl alcohol (PFA) tend to get prematurely cured and viscous during storage. Understanding a resin shelf-life is very helpful but no definite and validated method could be found in both scientific literature and standard methods. Cure kinetics of PFA was determined through tracing the complex viscosity changes as a function of time at elevated temperatures of 160, 170, 180, 190 and 200 degrees C. Adopting an empirical statistical approach, shelf-life of PFA resin at ambient temperature was estimated using the accelerated cure profiles. To this end, two functions were fitted on experimental results and then the empirical cure reaction rate constants at different temperatures were extrapolated to 25 degrees C. Subsequently, the viscosity versus time profiles were built for curing the resin at ambient temperature. The time interval corresponding to a viscosity range of 10-12.5 Pa.s was considered as the practical shelf-life of the resin at ambient conditions. The findings were validated by comparing the model results to the real-time, experimentally-obtained values.