Phenolic resin/coal char composites: Curing kinetics and thermal/mechanical performance

Abstract

Curing behavior plays a key role in determining the ultimate properties of thermosetting polymers. With the use of fillers, curing behavior and reaction kinetics are affected. Here, we report the study of the curing process and thermal and mechanical behaviors of phenolic composites reinforced with 50 wt% of an economic filler, coal char. Curing kinetics were investigated using non-isothermal differential scanning calorimetry (DSC) measurements and analyzed by model-free isoconversional methods for determining kinetic parameters. The study revealed that the coal char had a retarding effect on the curing of the phenolic resin. The curing reaction was also influenced by the processing method of the composite. Mixing of the char in tetrahydrofuran (THF) led to higher activation energies than via dry mixing. The mechanical properties and thermal stability of the phenolic resin were significantly improved in the presence of the filler. The information reported in this work can be used for optimal curing of phenolic resin/coal char composites as well as tuning performance by choosing an appropriate processing technique.