Degradation Of Polyethylene Over Nanostructured Catalysts Evaluated By TG And Pyrolysis-GC-MS

摘要

In the present work, was evaluated the catalytic degradation process of highrndensity dpolyethylene (HDPE) using nanoporous catalysts of type MCM-41, Al-MCM-rn41 e H-AlMCM- 41, through thermal analysis and pyrolysis coupled to gasrnchromatography and mass spectrometry. The kinetic relative to the HDPE degradationrnprocess was evaluated using the Flynn/Wall model, in order to verify the influence of thernMCM-41 materials on the process. The graphic of heating rate versus the inverse torntemperature for different degree of conversion permitted to determine the activationrnenergy, calculated from the slope of the straight line. By the integral curves, obtained forrnthe pure HDPE and HDPE mixed to MCM-41; AlMCM-41 and H-AlMCM-41, inrnnitrogen atmosphere and heating rates of 2.5; 5.0 and 10℃ min~(-1) , were determined thernfollowing order of activation energy for the process: HDPE > MCM-41 > H-AlMCM-41rn> AlMCM-41, evidencing that materials with Lewis acid sites (AlMCM-41) are morernefficient than those that present Bronsted acid sites (H-AlMCM41). The pyrolysis ofrnHDPE without catalyst produced a large range of hydrocarbons (C3-C27); whereas inrnpresence of the nanoporous materials were obtained hydrocarbons in the range of lightrngases (C2-C5); gasoline (C6-C9) and middle distilled (C10-C14), evidencing that thernpyrolisis mechanism is a function of the pore system and the acid properties.