Optimization of the Crystallization Process of Bis(2‐hydroxyethyl) Terephthalate

Abstract The crystallization process of bis(2‐hydroxyethyl) terephthalate is experimentally investigated. The optimized crystals of bis(2‐hydroxyethyl) terephthalate have the median particle size ( D 50 ) of 1300 µm and a perfect crystal habit, and their diameter span reduces from 11.48 (before optimization) to 1.72 (after optimization). The results show that more oxygen atoms at both ends of the crystal are exposed to the crystal surfaces, which make it easy to form hydrogen bonds with free bis(2‐hydroxyethyl) terephthalate. Therefore, the crystal surfaces at both ends grow fastest and tend to disappear eventually.