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This article discusses the effect of boiling inert hydrocarbon solvent on the model second-order transesterification reaction of ethylene/vinyl acetate copolymer with 3-phenyl I-propanol. In the presence of boiling, the overall reaction rate increases substantially due to mass-transfer effects in the proximity of the vapor-liquid interface. The present experiments and theory indicate that during the lifetime of a bubble in the boiling medium, the concentrations of reactants and the catalyst increase significantly near the bubble surface due to the rapid diffusion of the inert solvent. After the bubble rupture, the concentration differences persist and continue affecting the chemical reaction rate. The combination of these effects is responsible for the apparent increase in the overall reactivity.

This paper deals with the residence time distribution (RTD) in a non‐intermeshing counter rotating twin screw extruder. The RTDs were measured in three vent zones of the extruder sparately, and in the adjacent zones combined, using a soluble dye as the tracer. Assuming that the RTDs in the adjacent zones are independent of each other, the overall RTD was also calculated using a previously developed statistical theory. The theory has also confirmed the consistency of the present measurements. A predictive RTD model for the non‐intermeshing twin screw extruder, based on the flow analysis of the individual screw zones and their statistical superposition, was also developed. The predictions are in good agreement with experiment.

This work concerns some selected 3-0 flow effects on residence

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