The objective of this study is to characterize the effect of in situ heat treatment on polylactic acid (PLA) and plasticized PLA during fused deposition modelling (FDM) with the motivation to improve their mechanical, thermal and physical properties. The in situ heat treatment was formed during the FDM by adjusting the bed temperature to 70°C, 90°C and 120°C. The performance of 3D, the printed samples, was compared with the compression moulded samples treated at the same temperature using a vacuum oven. PLA was plasticized with poly (ethylene glycol) (PEG) at different compositions of 0, 5 and 10 wt% of PEG. The properties of PLA, plasticized PLA and FDM-printed sample were analysed using Instron, differential scanning calorimeter (DSC) and X-ray diffraction (XRD). It was found that the addition of PEG into PLA decreased the tensile strength, elongation at break and tensile modulus of the materials. However, after heat treatment in the vacuum oven and FDM, the properties were generally higher at 90°C and this was believed to be primarily due to the effect of crystallization. This can be proved by formation of double melting peak, correspond to melt-crystallization mechanism, observed in DSC. The formation of different crystal was supported by XRD analysis where the amorphous peak had transformed into sharp peak at 16.9° and 19.3°, which indicates an improved crystallinity. Comparison between the compression moulded sample and FDM demonstrated that the in situ heat treatment in FDM had the most significant impact on tensile modulus.

这项研究的目的是表征熔融沉积建模（FDM）过程中原位热处理对聚乳酸（PLA）和可塑PLA的影响，并旨在改善其机械，热和物理性能。通过将床温调节至70°C，90°C和120°C在FDM过程中形成原位热处理。使用真空烘箱将3D（打印样品）的性能与在相同温度下处理的压模样品进行比较。用聚（乙二醇）（PEG）以0、5和10 wt％的PEG的不同组成增塑PLA。使用Instron，差示扫描量热仪（DSC）和X射线衍射（XRD）分析了PLA，增塑PLA和FDM打印样品的性能。结果发现，向PLA中添加PEG会降低拉伸强度，材料的断裂伸长率和拉伸模量。然而，在真空烘箱和FDM中进行热处理后，性能通常在90℃下更高，这被认为主要是由于结晶作用。这可以通过在DSC中观察到的双熔峰的形成来证明，该峰对应于熔体结晶机理。通过XRD分析支持不同晶体的形成，其中无定形峰在16.9°和19.3°处转变为尖峰，这表明结晶度提高。压模样品与FDM之间的比较表明，FDM中的原位热处理对拉伸模量的影响最大。该性能通常在90℃下较高，这被认为主要是由于结晶作用。这可以通过在DSC中观察到的双熔峰的形成来证明，该峰对应于熔体结晶机理。通过XRD分析支持了不同晶体的形成，其中无定形峰在16.9°和19.3°处转变为尖峰，这表明结晶度提高。压模样品与FDM的比较表明，FDM中的原位热处理对拉伸模量的影响最大。该性能通常在90℃下较高，这被认为主要是由于结晶作用。这可以通过在DSC中观察到的双熔峰的形成来证明，该峰对应于熔体结晶机理。通过XRD分析支持不同晶体的形成，其中无定形峰在16.9°和19.3°处转变为尖峰，这表明结晶度提高。压模样品与FDM之间的比较表明，FDM中的原位热处理对拉伸模量的影响最大。通过XRD分析支持了不同晶体的形成，其中无定形峰在16.9°和19.3°处转变为尖峰，这表明结晶度提高。压模样品与FDM的比较表明，FDM中的原位热处理对拉伸模量的影响最大。通过XRD分析支持了不同晶体的形成，其中无定形峰在16.9°和19.3°处转变为尖峰，这表明结晶度提高。压模样品与FDM的比较表明，FDM中的原位热处理对拉伸模量的影响最大。