Method for synthesizing poly(butylene adipate-co-terephthalate)

摘要

A method for synthesizing poly(butylene adipate-co-terephthalate) by combination of melt and solid state polycondensation using an organic guanidine as a main catalyst. The ternary catalyst system includes a main catalyst, a first cocatalyst, and a second cocatalyst. The main catalyst is organic guanidine; the first cocatalyst is titanate ester or zirconate ester; and the second cocatalyst is metallic oxide. The method includes: 1) adding 1,4-butanediol (BDO), adipic acid (AA), terephthalic acid (TA), and a ternary catalyst system to a reaction still; conducting an oligo-polycondensation to yield a oligomer having the weight average molecular weight (M_w) of between 3.0×10³ and 4.0×10³; allowing the oligomer to perform a melt polycondensation (MP) to yield a prepolymer with medium M_w of between 1.5×10⁴ and 3.0×10⁴; and 2) crushing the solid prepolymer into granules of 30-40 meshes, and then allowing the granules to undergo solid state polycondensation to yield the final PBAT product.