PERCOLATION VIEW OF NOVOLAK DISSOLUTION .9. DEUTERIUM-ISOTOPE EFFECT ON DISSOLUTION RATE

A commercial Novolak resin was partially (OH groups) deuterated, and t he dissolution rate of the deuterated material in 0.1 N solutions of K OD, NaOD, and LiOD in D2O was measured. The dissolution of the deutera ted systems is considerably slower than that of the corresponding prot onated systems. In both cases the dissolution rate depends on the natu re of the base cation, and it is in fact a linear function of the reci procal cross section of the ions. These results are-compatible with th e view that the rate-determining step in Novolak dissolution is the de protonation of phenol groups at the interface of the penetration zone with the resin matrix. The dissolution of deuterated Novolak in deuter ated developers is strongly affected by the presence of salts of the b ase cations, in a manner similar to that of the protonated systems inv estigated in refs 1 and 2.