García-Campo María Jesús, Boronat Teodomiro, Quiles-Carrillo Luis, Balart Rafael, Montanes Nestor
Materials Science Division, Technological Institute of Materials, Universitat Politècnica de València, 03801 Alcoy, Alicante, Spain.
Manufacturing Engineering Division, Technological Institute of Materials, Universitat Politècnica de València, 03801 Alcoy, Alicante, Spain.
Polymers (Basel). 2017 Dec 21;10(1):3. doi: 10.3390/polym10010003.
Ternary blends with a constant poly(lactic acid) (PLA) content (60 wt %) and varying amounts of poly(3-hydroxybutyrate) (PHB) and poly(ε-caprolactone) (PCL) were manufactured by one step melt blending process followed by injection moulding, with the main aim of improving the low intrinsic toughness of PLA. Mechanical properties were obtained from tensile and Charpy impact tests. The miscibility and morphology of the system was studied by thermal analysis and field emission scanning electron microscopy (FESEM). The obtained results showed a clear phase separation, thus indicating poor miscibility between these three biopolyesters, i.e., PLA, the continuous component with dispersed PHB and PCL domains in the form of different sphere size. Nevertheless, the high fragility of PLA was remarkably reduced, as detected by the Charpy impact test. In accordance with the decrease in brittleness, a remarkable increase in elongation at break is achieved, with increasing PCL load due to its flexibility; in addition, increasing PCL load provides thermal stability at high temperatures. Thus, tailored materials can be manufactured by melt blending PLA, PHB, and PCL in different percentages to offer a wide range of biodegradable polymer blends.
通过一步熔融共混工艺，随后进行注塑成型，制备了具有恒定聚乳酸（PLA）含量（60 wt%）以及不同含量聚（3-羟基丁酸酯）（PHB）和聚（ε-己内酯）（PCL）的三元共混物，其主要目的是改善PLA较低的固有韧性。通过拉伸试验和夏比冲击试验获得力学性能。通过热分析和场发射扫描电子显微镜（FESEM）研究了该体系的相容性和形态。所得结果显示出明显的相分离，这表明这三种生物聚酯，即PLA（连续组分）与以不同球体尺寸形式分散的PHB和PCL域之间的相容性较差。然而，如通过夏比冲击试验所检测到的，PLA的高脆性显著降低。随着PCL负载量的增加，由于其柔韧性，断裂伸长率显著增加，这与脆性的降低相一致；此外，增加PCL负载量可在高温下提供热稳定性。因此，可以通过将PLA、PHB和PCL以不同百分比进行熔融共混来制造定制材料，以提供广泛的可生物降解聚合物共混物。
