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通过降解过程的质量损失率、相对分子质量及其分布、热性能、表面形貌等评价手段,重点考察了Aspergillus niger脂肪酶对聚丁二酸乙二醇酯(PES)和聚(丁二酸乙二醇-共-对苯二甲酸乙二醇酯)(PEST)的降解性能。结果表明:PES在脂肪酶溶液中具有较好的生物降解性能,随着对苯二甲酸摩尔含量的增加,PEST的质量损失率呈现先增加后逐渐减少的趋势;随着酶解时间的延长,残留部分的PES、PEST的相对分子质量均呈下降趋势;残留部分的PES、PEST的熔点随降解时间的延长变化不大,熔融热焓有所增加;聚酯薄膜表面产生了不同程度的沟槽、孔洞和裂纹。可以推测,PES及PEST的生物降解首先发生在无定形区,并且大分子链段发生的是随机断裂。
The effects of Aspergillus niger lipase on polyesters such as poly (butylene succinate) (PES) and poly (succinic acid) were investigated emphatically through the methods of mass loss, relative molecular mass and their distribution, thermal properties and surface topography. Ethylene glycol-co-ethylene terephthalate) (PEST). The results showed that PES had good biodegradability in lipase solution. With the increase of molar content of terephthalic acid, the mass loss rate of PEST firstly increased and then decreased gradually. With the extension of enzymolysis time, The relative molecular mass of PES and PEST in the residual part showed a decreasing trend. The melting point of PES and PEST in the residual part changed little with the prolongation of degradation time, and the enthalpy of fusion increased. The surface of the polyester film produced different degrees of grooves , Holes and cracks. It can be speculated that the biodegradation of PES and PEST first occurred in the amorphous region, and macromolecule segments occurred randomly.