Investigation of Thermal Stability of Bakelite by Isoconversional Thermal Analysis

Bakelite or polyoxybenzylmethyleneglycolanhydride is the world’s first fully synthetic plastic. This research work reports on thermal degradation profile of Bakelite using isoconversional thermal analysis as per the recommendation of International Confederation for Thermal Analysis and Calorimetry (ICTAC). For this purpose, thermal degradation of Bakelite was recorded on a SDT Q600 thermal analyzer at heating rates of 5, 10, 15 and 20 °C/min in the range between 20 to 1000 °C. We observed that the degradation of Bakelite occurred in three steps but the first and third steps are insignificant with respect to mass loss and kinetics. The initial and final degradation temperatures (Tdi, Tdf) of Bakelite were recorded between 205-228 °C and 378-427 °C, respectively at different heating rates. The mass loss associated with this phase was calculated about 59 %. The Tdm values were found to be 283-325 °C. Flynn-Wall-Ozawa (FWO) and Kissinger models were applied on the data to find the kinetic parameters such as activation energy (Ea) and order of reaction (n). The Ea value was found to be 102.73 and 104.31 kJ/mol as per FWO and Kissinger models while order of reaction was 1.09. Thermodynamic parameters were also found and the value of ∆H, ∆S and ∆G were found 97.89 kJ/mol, -141.60 kJ/K and 180.46 kJ/mol, receptively. This study explains that Bakelite is a thermally stable compound.