Abstract Thermal behaviors of poly(1,2-epoxy-4-epoxyethylcyclohexanes) (poly-EECH), polymerized by electroinitiation, radiation, and catalytic action of HClO4 and BF3-etharate, have been studied by direct pyrolysis MS and evolved gas analyses by mass and FT-IR spectrometric techniques. Direct pyrolysis experiments indicated that electroinitiated and catalytic polymerization of EECH with the use of BF3-etharate produced the least stable polymers thermally. High mass peaks were related to the presence of blocks propagated through the 1,2-epoxy group, especially in the polymer produced by catalytic action of BF3-etharate. Crosslinked structures were also justified by thermal analysis. Production of low molecular weight compounds such as CO, CO2, CH3OH, ethylene oxide, methylpropionate, and cyclohexane was investigated by evolved gas analysis.