Descending front of butyl acrylate

Figure 4. Rayleigh-Taylor instability with a descending front of butyl acrylate...

Figure 3. Rayleigh-Taylor instability with descending front of butyl acrylate polymerization. Although the polymer product is hot (> 200 °C) it still is about 20% more dense than the monomer below it.

Figure 16. Rayleigh-Taylor instability in a descending front of n-butyl acrylate polymerization.

Frontal polymerization can be achieved with a variety of monomers and has been studied with thermosets and thermoplastics. Examples include n-butyl acrylate, benzyl acrylate, styrene, dodecyl acrylate and hexyl acrylate. If the front is ascending, the monomer inmiediately above the front is lower in density because of the temperature gradient than the bulk monomer and so simple convection can occur for a thermoset (/P) or a thermoplastic. 20) A descending front with a thermoset is stable but a thermoplastic is unstable because even though the polymer is very hot, it is more dense than the unreacted monomer. This leads to the Rayleigh-Taylor instability. 16,21)... 

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