阳离子-π交联吲哚基高强韧聚乙烯醇薄膜的制备与表征

Preparation and Characterization of Cation-πCross-linked Indolyl High-strength and Tough Polyvinyl Alcohol Films

针对传统聚乙烯醇材料存在的力学性能不足问题,以阳离子-π为驱动力构筑了分子链间动态交联网络。以3-异氰酸酯基-2-苯基吲哚为吲哚基载体制备了吲哚基聚乙烯醇线性聚合物(PVAI),通过添加适量的MgCl_(2)制备阳离子-π交联的吲哚基聚乙烯醇薄膜(PVAI-Mg),利用热重分析仪、差示扫描量热仪、电子万能试验机、红外光谱仪等对薄膜的结构和性能进行了表征。结果表明:当Mg^(2+)掺杂摩尔分数为吲哚基元的7.5%时,交联薄膜拉伸强度达50.97 MPa(聚乙烯醇薄膜为19.47 MPa),断裂伸长率为402.3%(聚乙烯醇薄膜为368.8%),表明Mg^(2+)与吲哚间的阳离子-π相互作用改善了薄膜的力学性能。

In this study,we address the issue of insufficient mechanical properties in traditional polyvinyl alcohol materials.To overcome this limitation,we propose using cation-πinteractions to construct a dynamic cross-linking network between molecular chains.Specifically,we employ 3-isocyanato-2-phenylindole as indole-based carrier to prepare an indolyl polyvinyl alcohol linear polymer(PVAI).Subsequently,we introduce an appropriate amount of MgCl_(2)to create a cationic-πcross-linked indole-based polyvinyl alcohol film(PVAI-Mg).The film’s structure and performance were characterized using various techniques,including thermo-gravimetric analysis,differential scanning calorimetry,electronic universal testing machine,and infrared spectroscopy.Our findings reveal that when the Mg^(2+)doping amount is 7.5%of the molar amount of indole units,the tensile strength of the crosslinked film is 50.97 MPa(the tensile strength of the PVA film is 19.47 MPa),and the elongation at break of the crosslinked film is 402.3%(the elongation at break of the PVA film is 368.8%).These results indicate that the interaction of Mg^(2+)and cation-πin indole significantly enhances the mechanical properties of the film.