Bianchi Marica, Dorigato Andrea, Morreale Marco, Pegoretti Alessandro
Department of Industrial Engineering and INSTM Research Unit, University of Trento, Via Sommarive 9, 38123 Trento, Italy.
Faculty of Engineering and Architecture, Kore University of Enna, Cittadella Universitaria, 94100 Enna, Italy.
Polymers (Basel). 2023 Feb 10;15(4):881. doi: 10.3390/polym15040881.
Biodegradable polymers have recently become popular; in particular, blends of poly(lactic acid) (PLA) and poly(butylene adipate terephthalate) (PBAT) have recently attracted significant attention due to their potential application in the packaging field. However, there is little information about the thermomechanical properties of these blends and especially the effect induced by the addition of PBAT on the shape memory properties of PLA. This work, therefore, aims at producing and investigating the microstructural, thermomechanical and shape memory properties of PLA/PBAT blends prepared by melt compounding. More specifically, PLA and PBAT were melt-blended in a wide range of relative concentrations (from 85/15 to 25/75 wt%). A microstructural investigation was carried out, evidencing the immiscibility and the low interfacial adhesion between the PLA and PBAT phases. The immiscibility was also confirmed by differential scanning calorimetry (DSC). A thermogravimetric analysis (TGA) revealed that the addition of PBAT slightly improved the thermal stability of PLA. The stiffness and strength of the blends decreased with the PBAT amount, while the elongation at break remained comparable to that of neat PLA up to a PBAT content of 45 wt%, while a significant increment in ductility was observed only for higher PBAT concentrations. The shape memory performance of PLA was impaired by the addition of PBAT, probably due to the low interfacial adhesion observed in the blends. These results constitute a basis for future research on these innovative biodegradable polymer blends, and their physical properties might be further enhanced by adding suitable compatibilizers.
可生物降解聚合物近来颇受青睐；尤其是聚乳酸（PLA）与聚己二酸丁二醇酯-对苯二甲酸丁二醇酯（PBAT）的共混物，因其在包装领域的潜在应用，近期备受关注。然而，关于这些共混物的热机械性能，特别是添加PBAT对PLA形状记忆性能的影响，相关信息甚少。因此，本研究旨在制备并研究通过熔融共混法制备的PLA/PBAT共混物的微观结构、热机械性能及形状记忆性能。更具体地说，PLA和PBAT在较宽的相对浓度范围内（从85/15至25/75 wt%）进行熔融共混。开展了微观结构研究，结果表明PLA和PBAT相之间不相容且界面粘附力低。差示扫描量热法（DSC）也证实了这种不相容性。热重分析（TGA）表明，添加PBAT略微提高了PLA的热稳定性。共混物的刚度和强度随PBAT含量的增加而降低，而在PBAT含量达到45 wt%之前，断裂伸长率与纯PLA相当，只有在PBAT浓度更高时，才观察到延展性显著增加。添加PBAT会损害PLA的形状记忆性能，这可能是由于共混物中观察到的低界面粘附力所致。这些结果为未来对这些新型可生物降解聚合物共混物的研究奠定了基础，通过添加合适的增容剂，其物理性能可能会进一步提高。
