Mechanism of Catalytic Degradation

Researchers [2, 40] have investigated the catalytic degradation of polyolefins, using TGA, as a potential method for screening catalysts and have found that the presence of a catalyst led to a decrease in the apparent activation energy. There are different steps in the carbonium ion reaction mechanism, such as H-transfer, chain/] scission. 

ASA Amorphous silica alumina FCC Fluid catalytic cracking HMCM Hydrogen form of MCM HY Hydrogen containing Y-type zeolite MOR Mordenite MCM Mobil crystalline material REY Rare earth Y SAHA Si02(silica)-Al203 (alumina) with 40 wt% HZSM-5 and 20 wt% ludox SBA Santa Barbara amorphous type material  

Solid acid catalysts, such as zeolites, favour hydrogen transfer reactions due to the presence of many acid sites [2, 16]. Both Bronsted and Lewis acid sites characterise 

Propagation The hydrocarbon radical decomposes to produce lower hydrocarbons, such as propylene, followed by (3 scission (Equation 8.5) and the abstraction of H-radicals from other hydrocarbons to produce a new hydrocarbon radical (Equation 8.6)  

Termination The disproportionation or recombination of two radicals shown in Equations 8.7 and 8.8  

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