Analysis of different products obtained by reaction of diethylketone and hydrogen peroxide was performed under slightly different experimental conditions (mineral acid used, concentration of hydrogen peroxide, temperature, etc.). The product considered in this work is a white crystalline solid (mp. 59-60 ºC) identified as the cyclic trimeric peroxide or diethylketone triperoxide. Kinetic data of the thermal decomposition reaction of the triperoxide in different media demonstrate that the investigated reaction depends directly on the solvent properties, so a comparative analysis of the reactivity of the triperoxide in different solvents and the solvent effect is discussed. Reactivity of the triperoxide increases in more polar solvents. The activation parameters, ∆H^# and ∆S^#, corresponding to the homolytic dissociation of the O-O bond of the triperoxide molecule, in different solvent media, show the occurrence of enthalpy-entropy compensation (∆H^# = ∆H₀^# + β  ∆S^#) with an isokinetic temperature (β) of 445.2 K. The increasing ∆H^# values correspond to increasing ∆S^# values, so the reactions studied constitute a reaction series with enthalpy-entropy compensation. The thermal cycle-opening reaction takes place through the homolytic rupture of the O-O bond and a general homolytic reaction mechanism in the different solvents studied is postulated. The intermediate biradical initially formed by the homolytic rupture can be use as an effective initiator in styrene polymerization and its performance is similar to that presented by a multifunctional initiator giving rise to high molecular weight polystyrene at high reaction rates.