THERMOLYSIS OF ORTHONOVOLACS .1. PHENOL-FORMALDEHYDE AND M-CRESOL FORMALDEHYDE RESINS

A sequence of phenol-formaldehyde and m-cresol-formaldehyde orthonovol ac resins were synthesized by varying the mole ratios of phenol or sub stituted phenol to formaldehyde. The resins were characterized by thei r thermal properties such as softening temperatures and degradation pr ofile. The non-isothermal procedures of Coats-Redfern and Horowitz-Met zger were applied to their respective differential thermogravimetric p lots to ascertain the thermal degradation kinetics of these resins in air. The thermal stability and activation energies (E) of m-cresol-for maldehyde resins in the terminal degradation stage were correlated wit h those of the phenol-formaldehyde resins. The effect of aromatic ring substitution on the thermal stability is also discussed.