芳纶纳米纤维增强聚乙烯醇复合膜的制备与性能

Preparation and Performance Research of Aramid Nanofibers Reinforced Polyvinyl Alcohol Composite Films

以芳纶纤维Kevlar@49为原料,在温和条件下制备了芳纶纳米纤维分散体（ANFS）,并利用分散体制备了芳纶纳米纤维/聚乙烯醇（ANFs/PVA）复合膜。通过傅里叶红外光谱（FTIR）仪、差示扫描量热（DSC）仪、原子力显微镜（AFM）、扫描电子显微镜（SEM）、电子万能试验机及透光度/雾度测定仪等考察了复合膜的微观结构、热学、光学及力学性能。FTIR证明,复合膜中ANFs与PVA具有一定的分子间氢键作用,促进了ANFs在PVA基体中的分散。由AFM和SEM可以清晰观察到直径为20~30 nm的芳纶纳米纤维分散体,并且通过SEM观察到复合膜表面较为平整。当芳纶纳米纤维质量分数为6.0%时,复合膜的抗拉强度为17.86 MPa,断裂伸长率为442%;透光度为82.63%,雾度为27.56%;玻璃化温度,熔融温度和结晶温度分别为75.20、208.82和174.51℃,表明其透光性良好,力学和热学性能达到最佳。

Aramid nanofiber dispersion was prepared from commercial aramid fiber Kevlar@49 under mild conditions, and then aramid nanofiber reinforced poly（vinyl alcohol）（ANFs/PVA） composite films were fabricated. The microstructure, thermal, optical and mechanical behaviors of composite films were characterized by Fourier transform infrared spectroscopy（FTIR）, differential scanning calorimetry（DSC）, atomic force microscopy（AFM）, scanning electron microscopy（SEM）, electronic universal testing machine and optical transmittance/fog tester. The FTIR results revealed the hydrogen bonding interactions between aramid nanofibers and PVA promoted the dispersion of aramid nanofibers in PVA matrix. Aramid nanofibers with diameters ranging from 20 nm to 30 nm were clearly observed by AFM and SEM, and the surface of the prepared composite film was relatively smooth. The resultant composite film containing 6.0% aramid nanofibers（mass fraction） exhibited the best mechanical and thermal properties and excellent transparency with a tensile strength of 17.86 MPa, an elongation at break of 442%, a transparency of 82.63% and a haze of 27.56%. The glass transition temperature, melting temperature and crystallization temperature of composite film were 75.20, 208.82 and 174.51 ℃, respectively.