Abstract
The optimum reaction conditions in solid-state polycondensation of poly (1, 4-butylene terephthalate) (PBT) were investigated in order to obtain high molecular weight PBT. It was found that the solid-state polycondensation of PBT proceeds at a temperature in the range of 185 to 200°C under reduced pressure. This is due to the fact that the activation energy of the polycondensation reaction is 29.5kcal/mol and considerably smaller than that of the thermal decomposition reaction of PBT, i.e., ca. 40kcal/mol. To accelerate the reaction rate, it is important to carry out the polycondensation reaction at low humidity using PBT having a low carboxyl end group content and a large specific surface area.
