High-temperature degradation of reinforced phenolic insulator

✍ Scribed by İlhami Pektaş

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 193 KB
• Volume: 67
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/(sici)1097-4628(19980314)67:11<1877::aid-app6>3.0.co;2-i

✦ Synopsis

The thermal degradation of graphite and glass-reinforced phenolic insulators have been studied at high temperature by using thermogravimetry analysis (TGA) and Differential Scanning Calorimetry (DSC) analysis. TGA was carried out in a stream of pure nitrogen over temperature range ambient to 900ЊC and DSC analysis to 500ЊC. A heating rate of 10ЊC/min was used for the determination of degradation temperature and heating rates of 5, 10, 20, 30, and 50ЊC/min were used for the estimation of degradation temperature ( T max ) of the insulator at high temperature service and calculation of activation. Activation energy of phenolic resin was calculated as 356 kJ mol 01 using the Ozawa method. T max was determined as 661ЊC for 20% conversion. The specific heat capacity of graphite phenolic was found as 970 J kg 01 K 01 at 100ЊC. The half-life of the phenolic resin was determined to be approximately 116.2 s at 3500ЊC. The thermal analysis has been conducted using transient heat conduction and the in-depth temperature distribution was evaluated along the rocket nozzle. The better insulator thickness, including the safety factor for graphite and E-glass-reinforced phenolics, were calculated as 3 and 2 mm, respectively.