Tannin–phenolic resins: Synthesis, characterization, and application as matrix in biobased composites reinforced with sisal fibers

A tannin–phenolic resin (40 wt% of tannin, characterized by 1H nuclear magnetic resonance (NMR) and 13C NMR, Fourier transform infrared, thermogravimetry, differential scanning calorimetry) was used to prepare composites reinforced with sisal fibers (30–70 wt%). Inverse gas chromatography results showed that the sisal fibers and the tannin–phenolic thermoset have close values of the dispersive component and also have predominance of acid sites...