Paszkiewicz Sandra, Irska Izabela, Zubkiewicz Agata, Szymczyk Anna, Piesowicz Elżbieta, Rozwadowski Zbigniew, Goracy Krzysztof
Department of Materials Technologies, West Pomeranian University of Technology, Al. Piastów 19, 70-310 Szczecin, Poland.
Department of Technical Physics, West Pomeranian University of Technology, Al. Piastów 48, 70-311 Szczecin, Poland.
Polymers (Basel). 2021 Jan 27;13(3):397. doi: 10.3390/polym13030397.
A series of poly(hexamethylene 2,5-furanodicarboxylate)-block-poly(tetrahydrofuran) (PHF--F-pTHF) copolymers were synthesized using a two-stage procedure, employing transesterification and polycondensation. The content of pTHF flexible segments varied from 25 to 75 wt.%. H nuclear magnetic resonance (NMR) and Fourier transformed infrared spectroscopy (FTIR) analyses were applied to confirm the molecular structure of the materials. Differential scanning calorimetry (DSC), dynamic mechanical measurements (DMTA), and X-ray diffraction (XRD) allowed characterizing the supramolecular structure of the synthesized copolymers. SEM analysis was applied to show the differences in the block copolymers' morphologies concerning their chemical structure. The influence of the number of flexible segments in the copolymers on the phase transition temperatures, thermal properties, as well as the thermo-oxidative and thermal stability was analyzed. TGA analysis, along with tensile tests (static and cyclic), confirmed the utilitarian performance of the synthesized bio-based materials. It was found that an increase in the amount of pTHF caused the increase of both number-average and weight-average molecular weights and intrinsic viscosities, and at the same time causing the shift of the values of phase transition temperatures toward lower ones. Besides, PHF--F-pTHF containing 75 wt.% of F-pTHF units was proved to be a promising thermoplastic shape memory polymer (SMP) with a switching temperature of 20 °C.
采用酯交换和缩聚两步法合成了一系列聚（2,5-呋喃二甲酸己二酯）-嵌段-聚（四氢呋喃）（PHF-F-pTHF）共聚物。pTHF柔性链段的含量在25 wt.%至75 wt.%之间变化。采用氢核磁共振（NMR）和傅里叶变换红外光谱（FTIR）分析来确认材料的分子结构。差示扫描量热法（DSC）、动态力学测量（DMTA）和X射线衍射（XRD）用于表征合成共聚物的超分子结构。采用扫描电子显微镜（SEM）分析来展示嵌段共聚物在形态上与其化学结构相关的差异。分析了共聚物中柔性链段数量对相变温度、热性能以及热氧化稳定性和热稳定性的影响。热重分析（TGA）以及拉伸试验（静态和循环）证实了合成的生物基材料的实用性能。发现pTHF含量的增加导致数均分子量和重均分子量以及特性粘度均增加，同时导致相变温度值向更低温度偏移。此外，含有75 wt.% F-pTHF单元的PHF-F-pTHF被证明是一种有前景的热塑性形状记忆聚合物（SMP），其转变温度为20℃。
