新型仿皮肤液晶聚氨酯弹性体的合成及其电子器件的制备

Synthesis of a new skin-like liquid crystal polyurethane elastomer and preparation of electronic devices

为研制与人体具有适配性的柔性基材,采用简单的一锅法合成了新型仿皮肤交联液晶聚氨酯(crosslinked liquid crystal polyurethane,CLCPU)弹性体。利用傅里叶变换红外光谱(Fourier transform infrared spectroscopy,FTIR)对液晶聚氨酯的结构进行了表征,采用热失重分析仪(thermogravimetric analyzer,TGA)和差示扫描量热仪(differential scanning calorimetry,DSC)对其进行热学性能表征,用动态热机械分析仪(dynamic mechanical analyzer,DMA)测试其黏弹性行为,利用热台偏光显微镜(polarized optical microscope,POM)和电子万能试验机分别测试液晶聚氨酯的液晶相行为和力学性能。进一步将所制备材料作为介电弹性体组装柔性摩擦纳米发电机(triboelectric nanogenerator,TENG),并用静电计对所获的TENG进行电输出性能测试。研究结果表明:合成的CLCPU表现出向列相液晶纹理,具有宽液晶相区间(30~200℃);其具有低模量((0.143±0.009)MPa)、高拉伸性(约1200%)及良好的弹性等类皮肤力学性能特点。由该CLCPU构建的TENG具有出色的电学性能(开路电压约275 V),有望应用于可穿戴式电源和生理监测领域。

In order to develop flexible substrates suitable for human body,a new skin-like crosslinked liquid crystal polyurethane(CLCPU)elastomer was synthesized by simple one-pot method.The structure of liquid crystal polyurethane was characterized by Fourier transform infrared spectroscopy(FTIR).Thermal properties of liquid crystal polyurethane elastomer were investigated by thermogravimetric analyzer(TGA)and differential scanning calorimetry(DSC).The viscoelasticity of liquid crystal polyurethane was characterized by dynamic mechanical analyzer(DMA).The liquid crystal phase behavior and mechanical properties of liquid crystal polyurethane were tested by polarized opticalmicroscope (POM ) and universal electronic testing machine respectively. Flexible triboelectricnanogenerator (TENG) was fabricated by using the prepared material as dielectric elastomer and theelectrical output performance of the obtained TENG was tested by electrometer. The results show thatthe synthesized CLCPU exhibits nematic phase texture and has a wide liquid crystal phase range (30-200) ℃. Mechanical tests show that CLCPU has similar mechanical properties to skin, including lowmodulus ((0.143±0.009)MPa), high stretchability (about 1 200%) and good elasticity. The TENGconstructed by CLCPU as dielectric elastomer has good electrical properties (open circuit voltage about275 V), which is expected to be used in the field of wearable power supply and physiological monitoring.