Chrysafi Iouliana, Ainali Nina Maria, Bikiaris Dimitrios N
Laboratory of Advanced Materials and Devices, Department of Physics, Faculty of Sciences, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
Laboratory of Polymers Chemistry and Technology, Department of Chemistry, Faculty of Sciences, Aristotle University of Thessaloniki, GR-54124 Thessaloniki, Greece.
Polymers (Basel). 2021 Apr 22;13(9):1365. doi: 10.3390/polym13091365.
Ιn this work, new block poly(lactic acid)-block-poly(hexylene succinate) (PLA-b-PHSu) copolymers, in different mass ratios of 95/05, 90/10 and 80/20 /, are synthesized and their thermal and mechanical behavior are studied. Thermal degradation and thermal stability of the samples were examined by Thermogravimetric Analysis (TGA), while thermal degradation kinetics was applied to better understand this process. The Friedman isoconversional method and the "model fitting method" revealed accurate results for the activation energy and the reaction mechanisms (nth order and autocatalysis). Pyrolysis-Gas Chromatography/Mass Spectrometry (Py-GC/MS) was used to provide more details of the degradation process with PHSu's mechanism being the -hydrogen bond scission, while on PLA the intramolecular -esterification processes domains. PLA-b-PHSu copolymers decompose also through the -hydrogen bond scission. The mechanical properties have also been tested to understand how PHSu affects PLA's structure and to give more information about this new material. The tensile measurements gave remarkable results as the elongation at break increases as the content of PHSu increases as well. The study of the thermal and mechanical properties is crucial, to examine if the new material fulfills the requirements for further investigation for medical or other possible uses that might come up.
在这项工作中，合成了质量比分别为95/05、90/10和80/20的新型嵌段聚乳酸-嵌段聚己二酸丁二醇酯（PLA-b-PHSu）共聚物，并对其热性能和力学性能进行了研究。通过热重分析（TGA）检测了样品的热降解和热稳定性，同时应用热降解动力学来更好地理解这一过程。Friedman等转化率方法和“模型拟合方法”给出了关于活化能和反应机理（n级和自催化）的准确结果。热解气相色谱/质谱联用仪（Py-GC/MS）用于提供降解过程的更多细节，PHSu的降解机理是氢键断裂，而PLA上是分子内酯化过程。PLA-b-PHSu共聚物也通过氢键断裂分解。还测试了力学性能，以了解PHSu如何影响PLA的结构，并提供有关这种新材料的更多信息。拉伸测量结果显著，随着PHSu含量的增加，断裂伸长率也增加。热性能和力学性能的研究至关重要，以检验这种新材料是否满足进一步用于医学或其他可能出现的用途的研究要求。
