Reaction Injection Molding and Reactive Extrusion

Phases Liquid, liquid-liquid. Viscosities 1000 mPa s time for reaction to gel under adiabatic conditions 0.1 s small capacity 0.150-2 kg/s. 

Viscosity 10-100 mPa s to prevent bubbles Re 300 fill time 1 s and less than the reaction time to gel under adiabatic conditions. Mold temperature 100 °C (or 200 °C for high temperature operation). Mold temperature plus the adiabatic reaction exotherm must not exceed the degradation temperature. Reaction should be 95 % complete in 3 min. 

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Reaction injection molding and reactive extrusion k k Highly viscous. 

Reactive Processing n A molding or extrusion operation in which chemical reactions are carried out. Extruders, mainly specialized twin-screw machines, have successfully carried out partial and complete polymerizations on a large scale. Transfer and compression molding of thermosets have always been reactive processes, but see Reaction Injection Molding. 

The term reactive processing is used to describe a polymer processing that involves chemical reactions. In principle, any processing operation can be conducted as a reactive process, viz. reactive injection molding (RIM). However, most often the term refers to reactive extrusion, and in particular, to the reactive compatibilization of immiscible polymer blends, usually conducted in a TSE. During the last 50 years, the latter machines have been used as chemical reactors for the polymerization, depolymerization (chemical recycling), polymer modification and compatibilization [Brown, 1992, Xanthos, 1992 Utracki, 1989, 1991, 1994, 1997]. 

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