Abstract: 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 (Mw) of between 3.0×103 and 4.0×103; allowing the oligomer to perform a melt polycondensation (MP) to yield a prepolymer with medium Mw 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.

Abstract: A method for synthesizing poly(butylene succinate) (PBS) having a weight average molecular weight (Mw) equal to or larger than 1.4×105. The method employs biogenic guanidine (BG) as the main catalyst and includes: a) adding succinic acid (SA), 1.4-butanediol (BDO), and biogenic guanidine to a reactor, heating the reactor to a temperature of between 180 and 200° C. and conducting the esterification between succinic acid and 1.4-butanediol for 2 to 3 hours under atmospheric pressure until all of the water is distilled or boiled off; and b) adding a first cocatalyst, a second cocatalyst, and a third cocatalyst to the reactor, adjusting the absolute pressure in the reactor to be between 0.5 and 3 torr, and polycondensing the mixture in the reactor at the temperature between 210 and 230° C. over 20 to 30 hours.

Abstract: 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 (Mw) of between 3.0×103 and 4.0×103; allowing the oligomer to perform a melt polycondensation (MP) to yield a prepolymer with medium Mw 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.

Abstract: A method for synthesizing poly(butylene succinate) (PBS) having a weight average molecular weight (Mw) equal to or larger than 1.4×105. The method employs biogenic guanidine (BG) as the main catalyst and includes: a) adding succinic acid (SA), 1.4-butanediol (BDO), and biogenic guanidine to a reactor, heating the reactor to a temperature of between 180 and 200° C. and conducting the esterification between succinic acid and 1.4-butanediol for 2 to 3 hours under atmospheric pressure until all of the water is distilled or boiled off; and b) adding a first cocatalyst, a second cocatalyst, and a third cocatalyst to the reactor, adjusting the absolute pressure in the reactor to be between 0.5 and 3 torr, and polycondensing the mixture in the reactor at the temperature between 210 and 230° C. over 20 to 30 hours.