In this work, electrospun fibers of poly(butylene adipate-co-terephthalate) (PBAT) and poly(N-isopropylacrylamide) (PNIPAAm) blends, PBAT/PNIPAAm, with different mass ratios, were obtained. For characterization of their morphological, structural, thermal and wettability properties, scanning electron microscopy (SEM), attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), thermogravimetry (TG), differential scanning calorimetry (DSC) and drop water contact angle (DWCA) measurements were carried out. The optimum conditions determined for electrospinning were: voltage of 25 kV, flow rate of 1.3 mL·h−1 and working distance of 15 cm. The most important result was achieving PBAT/PNIPAAm electrospun fibers with a thermoresponsive behavior and a sudden response to temperature at PNIPAAm’s LCST (lower critical solution temperature). From SEM analysis, the higher the content of PNIPAAm in the blend, the higher the average diameter of the electrospun fibers was; also, the higher content of PNIPAAm in the blend allowed the fibers to be rounded with no presence of beads. From ATR-FTIR analysis, no formation of strong intermolecular interactions, such as hydrogen bonding, between the PBAT and PNIPAAm chains was observed. From TG and DSC analyses, the thermal stability of the PBAT/PNIPAAm fibers remained unchanged in respect to the electrospinning. DWCA measurements for PBAT/PNIPAAm 70/30 and 50/50 fibers, in response to temperature, indicated a gap of 50° to 60° at PNIPAAm’s LCST, evidencing their high thermosensitivity. With these results, PBAT/PNIPAAm electrospun fibers with 30% or more in mass ratio of PNIPAAm might find a potential application for the cell adhesion/detachment field.

中文翻译：

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新型热响应聚（己二酸丁二醇酯-共对苯二甲酸酯）/聚（N-异丙基丙烯酰胺）电纺纤维的表征

在这项工作中，获得了具有不同质量比的聚（己二酸丁二醇酯-共聚对苯二甲酸酯）（PBAT）和聚（N-异丙基丙烯酰胺）（PNIPAAm）共混物的电纺纤维，PBAT/PNIPAAm。为了表征它们的形态、结构、热和润湿性，扫描电子显微镜 (SEM)、衰减全反射傅里叶变换红外光谱 (ATR-FTIR)、热重 (TG)、差示扫描量热法 (DSC) 和滴水接触角 ( DWCA) 测量。静电纺丝的最佳条件为：电压25 kV，流速1.3 mL·h-1，工作距离15 cm。最重要的结果是实现了 PBAT/PNIPAAm 电纺纤维，其具有热响应行为和对 PNIPAAm 的 LCST（较低临界溶液温度）温度的突然响应。SEM分析表明，共混物中PNIPAAm的含量越高，电纺纤维的平均直径越大；此外，混合物中 PNIPAAm 的含量较高，可使纤维变圆且不存在珠粒。从 ATR-FTIR 分析中，没有观察到 PBAT 和 PNIPAAm 链之间形成强烈的分子间相互作用，例如氢键。从 TG 和 DSC 分析来看，PBAT/PNIPAAm 纤维的热稳定性在静电纺丝方面保持不变。PBAT/PNIPAAm 70/30 和 50/50 光纤的 DWCA 测量值响应温度，表明在 PNIPAAm 的 LCST 处存在 50° 至 60° 的间隙，证明它们的高热敏性。根据这些结果，PNIPAAm 质量比为 30% 或更多的 PBAT/PNIPAAm 电纺纤维可能会在细胞粘附/分离领域找到潜在的应用。