For the measurements, the as-prepared gels were dried and re-swollen in CDCl3 directly in the rotor insert. The state of the networks during these measurements is comparable to that during the second swelling experiment (Qv2). It should be mentioned here that, for preparation-related reasons, measurement of the co-networks directly after synthesis has not yet been possible for the determination of conversion p. The calculation of p followed the procedure reported for the kinetics experiments and gave conversions p ≥ 0.98 (see Table ) for the investigated co-networks, with the exception of CN2-5 (probably insufficient mixing before gelation). These measurements confirm that after removal of the sol fraction by Qv1 and subsequent evaporation of the synthesis solvent, virtually all benzoxazione groups were converted to benzamide groups.