Stereocomplex Formation of High-Molecular-Weight Polylactide Using Supercritical Fluid
Stereocomplex Formation of High-Molecular-Weight Polylactide Using Supercritical Fluid
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DOI：
10.1021/ma902536p
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发表时间：
2010-01-26
期刊：
影响因子：
5.5
通讯作者：
Kim, Soo Hyun
中科院分区：
文献类型：
--
作者：
Purnama, Purba;Kim, Soo Hyun
立体配合物聚乳酸袋被认为是提高聚乳酸性能的选择之一。对立体络合物的形成和表征进行了大量的研究，但这些研究在高分子量聚乳酸的情况下有局限性。在溶剂存在下，用超临界CO2观察了高分子量聚乳酸立体络合物的形成。此外，溶剂的加入增加了立体配合物的形成程度。我们评估了立体络合物形成的程度作为压力，溶剂浓度，温度和时间的函数。在浓度为30%的二氯甲烷、350 bar、65℃条件下形成立体配合物的程度较高，超临界co2溶剂形成立体配合物的程度高于溶液浇铸法，且在原位得到了干燥产物。与溶液浇铸法或均聚物相比，超临界法制得的立体配合物的热性能和力学性能有了显著的改善。
Stereocomplex polylactide bag been known as one of the choices to enhance the properties of polylactides. Numerous studies have been carried out on stereocomplex formation and characterizations, but these have a limitation in the case of high-molecular-weight polylactides. The stereocomplex formation of high-molecular-weight polylactides was observed by supercritical CO2 in the presence of solvent. Furthermore, the addition of solvent increased the degree of stereocomplex formation. We evaluated the degree of stereocomplex formation as a function of pressures, solvent concentration, temperature, and times. The high degree of stereocomplex formation was achieved at 30% of dichloromethane, 350 bar, and 65 degrees C. Compared with the solution casting method, stereocornplex formation by supercritical CO2-solvent had a higher degree of stereocomplex formation, and dry product was obtained in situ. Significant improvements of thermal and mechanical properties have been assessed for the stereocomplex obtained by supercritical method compared with either the solution casting method or their homopolymers.