Department of Industrial Engineering and INSTM Research Unit, University of Trento, Via Sommarive 9, 38123 Trento, Italy.
Laboratory of Polymer Chemistry and Technology, Chemistry Department, Aristotle University of Thessaloniki, 54124 Thessaloniki, Greece.
Molecules. 2023 Jun 16;28(12):4811. doi: 10.3390/molecules28124811.
This work presents the successful preparation and characterization of polylactide/poly(propylene 2,5-furandicarboxylate) (PLA/PPF) and polylactide/poly(butylene 2,5-furandicarboxylate) (PLA/PBF) blends in form of bulk and fiber samples and investigates the influence of poly(alkylene furanoate) (PAF) concentration (0 to 20 wt%) and compatibilization on the physical, thermal, and mechanical properties. Both blend types, although immiscible, are successfully compatibilized by Joncryl (J), which improves the interfacial adhesion and reduces the size of PPF and PBF domains. Mechanical tests on bulk samples show that only PBF is able to effectively toughen PLA, as PLA/PBF blends with 5-10 wt% PBF showed a distinct yield point, remarkable necking propagation, and increased strain at break (up to 55%), while PPF did not show significant plasticizing effects. The toughening ability of PBF is attributed to its lower glass transition temperature and greater toughness than PPF. For fiber samples, increasing the PPF and PBF amount improves the elastic modulus and mechanical strength, particularly for PBF-containing fibers collected at higher take-up speeds. Remarkably, in fiber samples, plasticizing effects are observed for both PPF and PBF, with significantly higher strain at break values compared to neat PLA (up to 455%), likely due to a further microstructural homogenization, enhanced compatibility, and load transfer between PLA and PAF phases following the fiber spinning process. SEM analysis confirms the deformation of PPF domains, which is probably due to a "plastic-rubber" transition during tensile testing. The orientation and possible crystallization of PPF and PBF domains contribute to increased tensile strength and elastic modulus. This work showcases the potential of PPF and PBF in tailoring the thermo-mechanical properties of PLA in both bulk and fiber forms, expanding their applications in the packaging and textile industry.
本文成功制备并表征了聚乳酸/聚（丙烯 2,5-呋喃二甲酸酯）（PLA/PPF）和聚乳酸/聚（丁烯 2,5-呋喃二甲酸酯）（PLA/PBF）的块状和纤维样品，并研究了聚（烷撑呋喃二甲酸酯）（PAF）浓度（0 至 20wt%）和增容对物理、热和机械性能的影响。虽然这两种共混物类型不混溶，但均成功地被 Joncryl（J）增容，这改善了界面附着力并减小了 PPF 和 PBF 畴的尺寸。块状样品的力学测试表明，只有 PBF 能够有效地增韧 PLA，因为 PLA/PBF 共混物中含有 5-10wt%的 PBF 时表现出明显的屈服点、显著的颈缩扩展和断裂伸长率增加（高达 55%），而 PPF 则没有表现出明显的增塑作用。PBF 的增韧能力归因于其较低的玻璃化转变温度和比 PPF 更大的韧性。对于纤维样品，增加 PPF 和 PBF 的量可提高弹性模量和机械强度，特别是对于在较高收卷速度下收集的含有 PBF 的纤维。值得注意的是，在纤维样品中，PPF 和 PBF 都表现出增塑作用，与纯 PLA 相比，断裂伸长率显著提高（高达 455%），这可能是由于纤维纺丝过程中进一步的微观结构均匀化、增强的相容性以及 PLA 和 PAF 相之间的负载传递。SEM 分析证实了 PPF 畴的变形，这可能是由于拉伸测试过程中发生了“塑料-橡胶”转变。PPF 和 PBF 畴的取向和可能的结晶有助于提高拉伸强度和弹性模量。本工作展示了 PPF 和 PBF 在以块状和纤维形式对 PLA 的热机械性能进行定制的潜力，扩展了它们在包装和纺织工业中的应用。
