Ferrer Inés, Manresa Ariadna, Méndez José Alberto, Delgado-Aguilar Marc, Garcia-Romeu Maria Luisa
Departament d'Enginyeria Mecànica i de la Construcció Industrial, EPS-Universitat de Girona, c/M. Aurèlia Capmany, 61-17003 Girona, Spain.
LEPAMAP-PRODIS Research Group, University of Girona, c/M. Aurèlia Capmany, 61-17003 Girona, Spain.
Polymers (Basel). 2021 Jul 22;13(15):2412. doi: 10.3390/polym13152412.
Ultrasonic molding (USM) is a good candidate for studying the plasticization of polymer mixtures or other composite materials due to either the little amount of material needed for processing, low waste or the needed low pressure and residence time of the mold. Thus, the novelty of this research is the capability of USM technology to process PLA/PCL blends and their corresponding neat materials, encompassing all the production stages, from raw material to the final specimen. The major findings of the work revealed that the thermal properties of the blends were not affected by the USM process, although the crystallinity degree experienced variations, decreasing for PLA and increasing for PCL, which was attributed to the crystallization rate of each polymer, the high process speed, the short cooling time and the small particle size. The employed ultrasonic energy increased the molecular weight with low variations through the specimen. However, the degradation results aligned with the expected trend of these material blends. Moreover, this study also showed the effect pellet shape and dimensions have over the process parameters, as well as the effect of the blend composition. It can be concluded that USM is a technology suitable to successfully process PLA/PCL blends with the correct determination of process parameter windows.
超声成型（USM）是研究聚合物混合物或其他复合材料增塑的理想选择，因为其加工所需材料量少、废料少，且模具所需压力和停留时间低。因此，本研究的新颖之处在于USM技术能够加工聚乳酸（PLA）/聚己内酯（PCL）共混物及其相应的纯材料，涵盖从原材料到最终样品的所有生产阶段。该工作的主要发现表明，共混物的热性能不受USM工艺的影响，尽管结晶度有所变化，PLA的结晶度降低，PCL的结晶度增加，这归因于每种聚合物的结晶速率、高加工速度、短冷却时间和小粒径。所采用的超声能量使样品的分子量增加且变化较小。然而，降解结果与这些材料共混物的预期趋势一致。此外，本研究还展示了粒料形状和尺寸对工艺参数的影响，以及共混物组成的影响。可以得出结论，通过正确确定工艺参数窗口，USM是一种适合成功加工PLA/PCL共混物的技术。
