Chemical stability, change control process

Heterogeneous catalysts are not just chemicals in the ordinary sense of the word they are performance chemicals or surface-active materials. Naturally, the performance of the catalyst will depend not so much on the initial composition or surface of it as on the real surface, which is formed and stabilized and then changing dynamically under the prevailing process conditions. Here one has to take into account known and controlled process parameters such as temperature, pressure, reactant concentration, and space velocity, as well as variable factors such as feed composition, and unpredictable or unsuspected factors such as impurities and poisons in the feed [65, 66]. 

The interfacial chemical reaction changes the dynamics of the phase inversion process. Sundaiaraj et al. [25] systematically studied the phase inversion process in a reactive polyarylate/ethylene-ethyl acrylate-glycidyl methacrylate rubber blend where the extent of interfacial chemical reaction was controlled by the addition of stearic acid. The primary effects of the interfacial reaction were to delay phase inversion and increase the mixing torque rise associated with it. Figure 5.6 illustrates both of these points. They attributed these effects to the fact that in reactive blends steric stabilization of the... 

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