Health & Environmental Research Online (HERO)


Print Feedback Export to File
2775886 
Technical Report 
Thermal Stability of Benzoyl Peroxide 
Uetake, K; Sankikawa, N 
1974 
NIOSH/00072181 
3 
575-583 
The thermal unstableness of benzoyl-peroxide (94360) (BPO) was investigated by means of pressure vessel test (PVT), ignition delay time, thermal gravitation (TG) and differential scanning calorimetric (DSC) methods. In addition, the analyses of thermal decomposition products and their reactions were carried out. The PVT curves showed that BPO decomposed violently at about 100 degrees centigrade with the evolution of white smoke, and hence the hazard of this material is very large. The white smoke produced was found by infrared (IR) analysis to be composed of benzoic-acid (65850), phenyl-benzoate, terphenyls and biphenyl. The melting point and the decomposition temperature of BPO were dependent upon heating rate, and the 5 degrees centigrade per minute was suitable to get the melting point of 105.5 to about 107 degrees centigrade and the decomposition temperature of 108 degrees centigrade. The ignition delay time depended upon the amount of sample; 150 milligrams were used. It was found by TG, DSC, IR, and the activation energy estimated from ignition delay time that the thermal decomposition of BPO at first occurred suddenly, followed by a milder reaction. The analysis of IR, thin layer chromatography and the pyrolysis gas chromatography revealed that the thermal decomposition of the pure BPO gave carbon-dioxide (124389), benzoic-acid and biphenyl as main products, together with some phenyl-benzoate, benzene and terphenyls. After 6 to 10 percent weight loss was perceived on TG curves, this decomposition reaction was accelerated by biphenyl which was produced by the decomposition of BPO. (Japanese; English translation available)