反应详情

1200 g of methyl methacrylate (12 mole), 20 g of ethylene glycol and 0.65 g of N,N'-diphenyl benzidine (500 ppm) are added to a 2 liter round-bottomed flask. After the addition of 12.9 g of potassium cyanide (1%), a quantity of methanol equivalent to the ethylene glycol employed is taken off as methyl methacrylate/methanol-azeotrope while conducting air through at a temperature of 65° C. at the head of the column (approximately 1/2 hour). After that, an additional 73g of ethylene glycol are dosed in within 2 hours (total quantity of ethylene glycol 93g=1.5 mole). After altogether 4.5 hours of removing azeotrope, the trans-esterification is completed. After cooling of the flask, the sump is filtered to remove the potassium cyanide, and the filter residue is washed with a little methyl methacrylate. The filtrate is concentrated at 40° C. under a water jet vacuum. A residue of ethylene glycol dimethacrylate of 286 g = 96.5% results. The ethylene glycol dimethacrylate obtained in such a way can be used either without any further processing or optionally after destabilization.

1. customthrough at a temperature of 65° C.
2. customat the head of the column (approximately 1/2 hour)
3. customAfter altogether 4.5 hours of removing azeotrope
4. temperatureAfter cooling of the flask
5. filtrationthe sump is filtered
6. customto remove the potassium cyanide
7. washthe filter residue is washed with a little methyl methacrylate
8. concentrationThe filtrate is concentrated at 40° C. under a water jet vacuum