Abstract
Phenol–formaldehyde (PF) resins were prepared with a level of 10, 20 and 30 % substitution of the phenol in the resin by three types of wheat gluten protein hydrolysates having different characteristics, namely (1) an enzymatic hydrolysate, (2) a lower molecular weight enzymatic hydrolysate, and (3) a middle sized molecular weight acid hydrolysate. All these resins were characterized by their pH, their viscosities and by thermo mechanical analysis. The mixed protein–phenolic oligomer species distribution formed in the preparation of these resins were identified by matrix assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry.