Mendoza-Duarte Mónica Elvira, Estrada-Moreno Iván Alziri, López-Martínez Erika Ivonne, Vega-Rios Alejandro
Centro de Investigación en Materiales Avanzados, SC, Av. Miguel de Cervantes #120, Chihuahua 31136, Mexico.
CONACyT-CIMAV, SC, Av. Miguel de Cervantes #120, Chihuahua 31136, Mexico.
Polymers (Basel). 2023 Jan 6;15(2):305. doi: 10.3390/polym15020305.
In this study, poly(lactic acid) (PLA) blended with different natural waxes (beeswax, candelilla, carnauba, and cocoa) was investigated. Different wax amounts, 3, 5, 10, and 15 wt%, were incorporated into the PLA using a Brabender internal mixer. The blends were characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), rotational rheometer (RR), dynamic mechanical analysis (DMA), and contact angle to observe the effect of the different waxes on the PLA physicochemical, rheological, mechanical behavior, and wetting properties. The complex viscosity of the blends was studied by employing a RR. The effect of the addition of the waxes on the mechanical properties of PLA was evaluated by DMA in the tension modality. A slight decrease in the thermal stability of PLA was observed with the addition of the waxes. However, in the case of the mechanical properties, the cocoa wax showed a considerable effect, especially in the elongation at break of PLA. Likewise, waxes had an essential impact on the water affinity of PLA. Specifically, with the addition of cocoa, the PLA became more hydrophilic, while the rest of the waxes increased the hydrophobic character.
在本研究中，对聚乳酸（PLA）与不同天然蜡（蜂蜡、小烛树蜡、巴西棕榈蜡和可可蜡）的共混物进行了研究。使用布拉本德密炼机将3、5、10和15重量百分比的不同蜡量加入到PLA中。通过热重分析（TGA）、差示扫描量热法（DSC）、旋转流变仪（RR）、动态力学分析（DMA）和接触角对共混物进行表征，以观察不同蜡对PLA的物理化学、流变、力学行为和润湿性的影响。采用RR研究共混物的复数粘度。通过DMA在拉伸模式下评估蜡的添加对PLA力学性能的影响。观察到添加蜡后PLA的热稳定性略有下降。然而，就力学性能而言，可可蜡表现出显著影响，尤其是对PLA的断裂伸长率。同样，蜡对PLA的亲水性有重要影响。具体而言，添加可可蜡后，PLA变得更亲水，而其他蜡则增加了其疏水性。
