Thermal Runaway Hazards of α -Methylstyrene and Trans-β -methylstyrene with Formaldehyde and Benzaldehyde

摘要

The purpose of this study was to estimate thermal runaway behaviors for styrene and its derivatives of α -methylstyrene (AMS) and trans-β -methylstyrene (TBMS) with formaldehyde and benzaldehyde. Experiments were carried out for evaluating the thermokinetic parameters by differential scanning calorimetry (DSC) and thermal activity monitor III (TAM III). The DSC results showed that when AMS and TBMS contacted the formaldehyde, both the exothermic onset temperature (T0) and total heat of reaction (H) were decreased. Dimerization and thermal polymerization were inhibited by formaldehyde. When AMS and TBMS contacted with benzaldehyde, T0 and exothermic peak temperature with respect to dimerization were alleviated. Thermal polymerization revealed that T0 was prominently reduced from 360.2 to 276.2°C By observation, autocatalytic reaction was demonstrated in thermal curves. Results of TAM III tests were applied to analyze the concentration profile versus time. By the Arrhenius equation, the AMS and TBMS combined with benzaldehyde of activation energy (Ea) were also computed, under the isothermal temperatures of 80, 90, 100, 110 and 120°C, respectively.