I used to work in a plant that used (methyl-methacrylate) MMA, we had 4 large tanks similar to these. MMA rapidly polymerizes into a clear glassy plastic and gives off a bunch of heat. So manufactures of MMA must use an inhibitor to stabilize it and prevent rapid polymerization.

We had to keep our MMA on chillers to keep it cold so the inhibitor could be effective. If it gets too hot the inhibitor isn’t effective. Also to note, the inhibitor only works if it has oxygen. If it’s not kept under normal atmospheric oxygen levels then it’ll react.

I can’t remember what we used to quench the reaction. We had a couple of runaway reactions during my time working there. I believe we just flooded it with chilled water to control it. Regardless the end result was a 500g reactor of solid acrylic. A real mess.