Valerga Ana P, Fernandez-Vidal Severo R, Girot Franck
Department of Mechanical Engineering and Industrial Design, School of Engineering, University of Cadiz, Av. Universidad de Cádiz, 10, Puerto Real, 11519 Cadiz, Spain.
IKERBASQUE, Basque Foundation for Science, 48013 Bilbao, Spain.
Polymers (Basel). 2023 Feb 9;15(4):862. doi: 10.3390/polym15040862.
Material extrusion (MEX), more commonly known as fused deposition modelling (FDM/FFF), is one of the most widely used techniques in polymeric Additive Manufacturing (AM). This technology is increasingly present in fields such as engineering and medicine with polymeric materials, including additives of many types. Polylactic acid polymer (PLA) is one of the most widely used materials currently on the market for MEX technology. In addition to its ease of printing, it is a plastic of natural origin, biodegradable and supplants petroleum derivatives in many applications. However, the effect of ageing on the mechanical properties of PLA are still to be evaluated and understood. The main objective of this work is to investigate the effects of ageing of PLA samples on the tensile properties. To investigate the effect of ageing, the samples were tested periodically after exposure to fertilized soil for a period up to 6 months. In addition, some of the samples were chemically pre-treated to improve the surface quality, and the effect of ageing on the treated and untreated samples was also evaluated. This study showed that ultimate strength decreased with ageing from 46 to 36 MPa (22%), and it increased with treatment time in high percentages (even 40%) depending on the time of immersion in the solvent. However, this effect of the chemical treatment gradually disappeared, with the exception of the surface improvement obtained.
材料挤出（MEX），更常见的名称是熔融沉积建模（FDM/FFF），是聚合物增材制造（AM）中使用最广泛的技术之一。这项技术在工程和医学等领域越来越多地应用于聚合物材料，包括多种类型的添加剂。聚乳酸聚合物（PLA）是目前市场上MEX技术使用最广泛的材料之一。除了易于打印外，它还是一种天然来源的塑料，可生物降解，并且在许多应用中取代了石油衍生物。然而，老化对PLA力学性能的影响仍有待评估和了解。这项工作的主要目的是研究PLA样品老化对拉伸性能的影响。为了研究老化的影响，将样品在暴露于施肥土壤长达6个月的时间后定期进行测试。此外，对一些样品进行化学预处理以改善表面质量，并评估老化对处理过和未处理过的样品的影响。这项研究表明，极限强度随着老化从46MPa降至36MPa（下降22%），并且根据在溶剂中的浸泡时间，处理后的强度会有很高的百分比增加（甚至达到40%）。然而，化学处理的这种效果逐渐消失，除了获得的表面改善之外。
