Klepić Martina, Fuoco Alessio, Monteleone Marcello, Esposito Elisa, Friess Karel, Petrusová Zuzana, Izák Pavel, Jansen Johannes Carolus
Department of Physical Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic.
Institute on Membrane Technology (CNR-ITM), Via P. Bucci, 17/C, 87036 Rende (CS), Italy.
Polymers (Basel). 2020 Apr 12;12(4):890. doi: 10.3390/polym12040890.
The last decade has seen an exponential increase in the number of studies focused on novel applications for ionic liquids (ILs). Blends of polymers with ILs have been proposed for use in fuel cells, batteries, gas separation membranes, packaging, etc., each requiring a set of specific physico-chemical properties. In this work, blends of four grades of the poly(ether-ester) multiblock copolymer PolyActive™ with different concentrations of the CO-philic 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide [BMIM][TfN] were prepared in the form of dense films by a solution casting and solvent evaporation method, in view of their potential use as gas separation membranes for CO capture. Depending on the polymer structure, the material properties could be tailored over a wide range by means of the IL content. All samples were dry-feeling, highly elastic self-standing dense films. The microstructure of the blends was studied by scanning electron microscopy with a backscattering detector, able to observe anisotropy in the sample, while a special topographic analysis mode allowed the visualization of surface roughness. Samples with the longest poly(ethylene oxide terephthalate) (PEOT) blocks were significantly more anisotropic than those with shorter blocks, and this heterogeneity increased with increasing IL content. DSC analysis revealed a significant decrease in the melting enthalpy and melting temperature of the crystalline PEOT domains with increasing IL content, forming an amorphous phase with ≈ -50 °C, whereas the polybutylene terephthalate (PBT) phase was hardly affected. This indicates better compatibility of the IL with the polyether phase than the polyester phase. Young's modulus was highest and most IL-dependent for the sample with the highest PEOT content and PEOT block length, due to its high crystallinity. Similarly, the sample with short PEOT blocks and high PBT content also showed a high modulus and tensile strength, but much lower maximum elongation. This study provides a detailed discussion on the correlation between the morphological, thermal, and mechanical properties of these PolyActive™/[BMIM][TfN] blends.
在过去十年中，专注于离子液体（ILs）新应用的研究数量呈指数级增长。聚合物与离子液体的共混物已被提议用于燃料电池、电池、气体分离膜、包装等领域，每个领域都需要一组特定的物理化学性质。在这项工作中，考虑到它们作为用于捕获CO的气体分离膜的潜在用途，通过溶液浇铸和溶剂蒸发法制备了四种等级的聚（醚 - 酯）多嵌段共聚物PolyActive™与不同浓度的亲CO的1 - 丁基 - 3 - 甲基咪唑双（三氟甲基磺酰）亚胺[BMIM][TfN]的共混物，其形式为致密膜。根据聚合物结构，可以通过离子液体含量在很宽的范围内调整材料性能。所有样品都是手感干燥、高弹性的自支撑致密膜。通过带有背散射探测器的扫描电子显微镜研究了共混物的微观结构，该显微镜能够观察样品中的各向异性，而一种特殊的形貌分析模式可以可视化表面粗糙度。具有最长聚（对苯二甲酸乙二酯）（PEOT）嵌段的样品比具有较短嵌段的样品明显更具各向异性，并且这种不均匀性随着离子液体含量的增加而增加。差示扫描量热法（DSC）分析表明，随着离子液体含量的增加，结晶PEOT域的熔化焓和熔化温度显著降低，形成了玻璃化转变温度约为 -50°C的非晶相，而聚对苯二甲酸丁二醇酯（PBT）相几乎不受影响。这表明离子液体与聚醚相的相容性比与聚酯相更好。由于其高结晶度，对于PEOT含量和PEOT嵌段长度最高的样品，杨氏模量最高且最依赖于离子液体。同样，具有短PEOT嵌段和高PBT含量的样品也显示出高模量和拉伸强度，但最大伸长率要低得多。本研究详细讨论了这些PolyActive™/[BMIM][TfN]共混物的形态、热和机械性能之间的相关性。
