Nondestructive Grafting of ZnO on the Surface of Aramid Fibers Followed by Silane Grafting to Improve its Interfacial Adhesion Property with Rubber

A method of nondestructive grafting of zinc oxide onto a fiber surface followed by silane grafting was demonstrated. We used tannic acid and polyethyleneimine to form functional surfaces onto aramid fibers, which can form chemical bonds with zinc oxide. Through in situ hydrothermal reductions, zinc oxide nanowires are uniformly grown onto aramid fibers. A polysulfide functionalized silane was then grafted, which can covulcanize with a rubber matrix. The interfacial adhesion between the modified fibers and rubber has an increase of 57.0%, compared with untreated aramid fibers, which demonstrated that the grafting of zinc oxide nanowires and the grafting of silane can play a combination effect on improving the interfacial adhesion. The results suggested that the growth process of zinc oxide nanowires has almost no effect on the breaking strength of aramid fibers.