Ethylene oligomers scale

PET and PBT can be eonveniently synthesized, both at laboratory and industrial scale, in the presenee of metal eatalysts in a two-step-polyesterification of the diols, ethylene glycol or 1,4-butanediol respectively, and dimethyl terephthalate (DMT) or terephthalic acid (TPA). The first step is basically a transesterification or esterification process depending on the use of DMT or TPA respectively, while the second step is the polycondensation of the resulting oligomers. The polycondensation step occurs at higher temperature and at reduced pressure to facilitate the distillation of the diols and consequently the polymerisation of the oligomers. 

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