PHENOL FORMALDEHYDE RESINS AS A LINK TO THE UNDERSTANDING OF THE ISOTHERMAL KINETIC-BEHAVIOR OF GEOPOLYMERS (KEROGENS AND COALS)

Phenol-formaldehyde resins (Bakelites) were synthesized using various phenol: formaldehyde ratios and phenol: base (NaOH) ratios. Isothermal kinetic experiments indicated that the preparation ratios had a marked influence on the kinetic profile. Whereas most synthetic polymers studied previously showed a marked difference between their kinetic profiles in comparison with geopolymers, some of the resins studied here exhibited similarity to the geopolymers (kerogens, coals). The relations between the resin structures and their isothermal kinetic behavior were studied. It was found that highly branched (coral like) stereometric structures will yield a kinetic behavior which resembles that of geopolymers. Low degree of branching will yield a kinetic behavior similar to that of common synthetic polymers. Previously we have suggested a kinetic model which explains the kinetic behavior of geopolymers and the difference between the kinetic behavior of geo- and synthetic polymers. The results described in the present paper support this model.