Polyester esterification under two different pressures

摘要: In the process for continuous production of highly polymeric synthetic linear polyester polymers, where ethylene glycol and terephthalic acid are reacted to form bis(beta hydroxy) ethyl terephthalate low molecular weight polymer thereafter subjected polycondensation - improvement is provided wherein a first phase esterification conducted at about 0-5 psig (0-0.35 kg/cm2 gauge) pressure through 75-95% esterification; during which water easily removed, as substantial amount glycol; second substantially higher than percent increased 95-99%.