Aramid fiber with excellent interfacial properties suitable for resin composite in a wide polarity range.

The weak interfacial adhesion of aramid fiber with resin matrix is believed as a major limitation for its wide application. In this study, a nondestructive grafting method was applied for surface modification of benzimidazole-contained aramid fiber. Using the NH in benzimidazole unit as active sites, aramid fiber surface was firstly decorated with densely SiO 2 structure, and a rough surface was obtained. Then, high density of NH 2 and C=C groups were introduced on fiber surface by the reaction with silane coupling agents. These functionalized NH 2 /C=C groups endow the fiber with the ability to chemically bonding with resin in a wide polarity range, including rubber, bismaleimide and epoxy resin. Also, the SiO 2 -decorated rough surface improves the level of mechanical interlocking with them. Experimental results show that the interfacial shear strength of functionalized fiber with natural rubber, bismaleimide and epoxy resin correspondingly increases 117%, 166% and 43%, compared with that of untreated fibers. Meanwhile, the grafting method is confirmed as nondestructive, and the superior mechanical property of aramid fiber is preserved. In all, the study presents a new effective method for the preparation of aramid fiber with excellent interfacial properties suitable for resin composite in a wide polarity range. [ABSTRACT FROM AUTHOR]