The characteristics of networks formed in cured ‘reworkable’ epoxy thermosets capable of controlled thermal degradation were studied.Dynamic mechanical thermal analysis, swelling measurements, and glass transition temperature measurements were used to obtain
information regarding the time and temperature dependence of the crosslink densities of these materials. By applying isothermal conditions,
networks containing up to 36 mol% non-degradable components could be completely degraded, i.e. progress from a network of infinite
molecular weight to a finite one with zero crosslink density. Percolation theory was used to facilitate the interpretation of these results. The
degradation behavior of the reworkable thermosets were well-described by gel degradation theory, i.e. the reverse of the gelation process, and
the experimental results were in good agreement with calculated values obtained by replacing the extent of reaction, p, in Macosko and
Miller’s branching theory with the extent of degradation, 1 2 p:
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