Methanol → Bis(2-hydroxyethyl) terephthalate

Participants

Reaction Steps

This example was carried out as described in Example 1, the reaction vessel being charged with the above analysed ethylene glycol (496 parts) and dimethyl terephthalate. Instead of adding solid sodium carbonate directly, a solution was made containing 0.1 part in ethylene glycol (25 parts by volume). This solution was placed in a burette which was fitted into a suitable vacuum-tight inlet in the reaction vessel. The mixture in the reaction vessel was heated to approximately 70°-75° C and the solution of sodium carbonate in ethylene glycol was added dropwise until 13.5 parts by volume had been added, when methanol began to distil. The theoretical volume of sodium carbonate required to neutralise the free acidity of the DMT was 13.6 parts by volume agreeing well, within the experimental limits, with that actually used before reaction began. The reaction continued normally and a yield of 208 parts (81.9%) of bis-(2-hydroxyethyl)-terephthalate was obtained m.pt. 108.4 - 109.8° C. The oligomer residue weighed 14.5 parts.

Provenance & Evidence