Yuan Jing, Zhang Xinpeng, Xu Jun, Ding Jianping, Li Wanli, Guo Baohua
Key Laboratory of Advanced Materials (MOE), Department of Chemical Engineering, Tsinghua University, Beijing 100084, China.
Xinjiang Blue Ridge Tunhe Sci. & Tech. Co., Ltd., Changji 831100, China.
Materials (Basel). 2024 Nov 23;17(23):5732. doi: 10.3390/ma17235732.
Two types of glycerol stearates, glycerol monostearate (GMS) and glycerol tristearate (GTS), were added into poly(butylene adipate-co-terephtalate) (PBAT), with the aim to improve their water vapor barrier properties. The effects of the two small molecules on microstructure, chain mobility, and surface hydrophobicity were amply assessed via both experimental and simulation methods. The incorporation of the modifiers at small loadings, 5 wt% of GMS and 1 wt% of GTS, resulted in substantial improvements in water vapor barrier properties, while a further increase in the modifier content resulted in deterioration. The optimal water vapor permeability reached values of 2.63 × 10 g·cm/(cm·s·Pa) and 6.55 × 10 g·cm/(cm·s·Pa), which are substantially lower than the permeability, 8.43 × 10 g·cm/(cm·s·Pa), of neat PBAT. The water vapor permeability of PBAT/GMS blends was also proven to be time-dependent and dramatically decreased with time, mainly due to the migration process of small molecules, forming a waterproof layer. The barrier improvement results are assumed to be related to the hydrophobic effect of glycerol stearate and are largely dependent on the content, polarity, compatibility, and dispersion of modifiers. In addition, the incorporation of modifiers did not largely sacrifice the mechanical strength of PBAT, which is advantageous in mulch film applications.
将两种类型的硬脂酸甘油酯，即单硬脂酸甘油酯（GMS）和三硬脂酸甘油酯（GTS）添加到聚（己二酸丁二醇酯-co-对苯二甲酸丁二醇酯）（PBAT）中，旨在改善其水蒸气阻隔性能。通过实验和模拟方法充分评估了这两种小分子对微观结构、链迁移率和表面疏水性的影响。在低负载量下加入改性剂，5 wt%的GMS和1 wt%的GTS，可显著改善水蒸气阻隔性能，而改性剂含量的进一步增加则会导致性能恶化。最佳水蒸气渗透率达到2.63×10 g·cm/(cm·s·Pa)和6.55×10 g·cm/(cm·s·Pa)，这大大低于纯PBAT的渗透率8.43×10 g·cm/(cm·s·Pa)。PBAT/GMS共混物的水蒸气渗透率也被证明与时间有关，并且随着时间的推移显著降低，这主要是由于小分子的迁移过程，形成了一个防水层。阻隔性能的改善结果被认为与硬脂酸甘油酯的疏水作用有关，并且在很大程度上取决于改性剂的含量、极性、相容性和分散性。此外，加入改性剂并没有大幅牺牲PBAT的机械强度，这在地膜应用中是有利的。
