Delgado-Aguilar Marc, Puig Rita, Sazdovski Ilija, Fullana-I-Palmer Pere
ABBU Research Group, Department of Computer Science and Industrial Engineering, Universitat de Lleida (UdL), Pla de la Massa 8, 08700 Igualada, Spain.
UNESCO Chair in Life Cycle and Climate Change ESCI-UPF, Universitat Pompeu Fabra, Passeig Pujades 1, 08003 Barcelona, Spain.
Materials (Basel). 2020 Jun 10;13(11):2655. doi: 10.3390/ma13112655.
Circular economy comes to break the linear resource to waste economy, by introducing different strategies, two of them being: using material from renewable sources and producing biodegradable products. The present work aims at developing polylactic acid (PLA), typically made from fermented plant starch, and polycaprolactone (PCL) blends, a biodegradable polyester, to study their potential to be used as substitutes of oil-based commodity plastics. For this, PLA/PCL blends were compounded in a batch and lab scale internal mixer and processed by means of injection molding. Tensile and impact characteristics were determined and compared to different thermoplastic materials, such as polypropylene, high density polyethylene, polystyrene, and others. It has been found that the incorporation of PCL into a PLA matrix can lead to materials in the range of 18.25 to 63.13 megapascals of tensile strength, 0.56 to 3.82 gigapascals of Young's modulus, 12.65 to 3.27 percent of strain at maximum strength, and 35 to 2 kJ/m of notched impact strength. The evolution of the tensile strength fitted the Voigt and Reuss model, while Young's modulus was successfully described by the rule of mixtures. Toughness of PLA was significantly improved with the incorporation of PCL, significantly increasing the energy required to fracture the specimens. Blends containing more than 20 wt% of PCL did not break when unnotched specimens were tested. Overall, it was found that the obtained PLA/PCL blends can constitute a strong and environmentally friendly alternative to oil-based commodity materials.
循环经济旨在打破从资源到废弃物的线性经济模式，通过引入不同策略，其中两种策略为：使用可再生资源材料和生产可生物降解产品。本研究旨在开发通常由发酵植物淀粉制成的聚乳酸（PLA）与可生物降解聚酯聚己内酯（PCL）的共混物，以研究其作为石油基通用塑料替代品的潜力。为此，在间歇式和实验室规模的内部混合器中制备了PLA/PCL共混物，并通过注塑成型进行加工。测定了拉伸和冲击性能，并与不同的热塑性材料（如聚丙烯、高密度聚乙烯、聚苯乙烯等）进行了比较。研究发现，将PCL加入PLA基体中可得到拉伸强度在18.25至63.13兆帕斯卡范围内、杨氏模量在0.56至3.82吉帕斯卡范围内、最大强度下应变在12.65至3.27%范围内以及缺口冲击强度在35至2千焦/米范围内的材料。拉伸强度的变化符合Voigt和Reuss模型，而杨氏模量则成功地用混合法则描述。加入PCL后，PLA的韧性显著提高，显著增加了使试样断裂所需的能量。当测试无缺口试样时，含有超过20 wt% PCL的共混物不会断裂。总体而言，研究发现所制备的PLA/PCL共混物可构成一种强大且环保的石油基通用材料替代品。
