Azo polymers - syntheses and reactions, 2. Selfcrosslinking, swelling and DSC experiments

Polymers containing azo groups and CC‐double bonds were crosslinked by heating to the temperature at which cleavage of the azo functions covalently linked to the polymer backbone takes place. The crosslinking process was characterized by swelling experiments and by DSC. From the reaction enthalpy the number of polymer chains initiated by one radical was estimated. Swelling experiments and DSC showed that the crosslinking efficiency of the radicals increases with the temperature at which the azo groups are split off and with the instability of the radicals. Polymers containing also functions with different thermostability were used for selective stepwise network formation.