摘要 |
A method is disclosed herein for the preparation of polytrimethylene terephthalate with sustained-release crystallinity. The method reduces crystallization rate and crystallinity-saturation ratio of polytrimethylene terephthalate during spinning, through addition of a third monomer during the esterification reaction step. The third monomer acts as copolymerization component generating intermolecular steric hindrance; the identity of which selects from one or more as combinations of the following: trimellitic anhydride, non-para aromatic dicarboxylic acid, C4-C10 aliphatic dicarboxylic acid having branched chains or naphthenic group and C3-C10 aliphatic dihydric alcohol having branched chains or naphthenic group, the molar ratio of carboxyl to hydroxyl is 1:1.16~1.85, with the third monomer constituting 0.5~6.5% of the total weight of the beginning raw materials. |