Optimization of preparation conditions of epoxy-containing nanocapsules

Abstract

Nanocapsules using epoxy and urea formaldehyde as core and shell materials, respectively, were prepared by in situ polymerization. The effects of processing conditions on the properties of epoxy nanocapsules were systematically investigated based on w(core) and average diameter of nanocapsules through the method of orthographic factorial design, and the optimum processing conditions were concluded. The results indicated that the key influencing factors on w(core) was agitation rate; on average, diameter of nanocapsules was emulsifier. The analysis of mechanical properties and thermal stability indicated that nanocapsules prepared in the optimum conditions are suitable for storage and the optimum content of nanocapsules was 10%. Scanning electron microscopy indicated that nanocapsules were well encapsuled and presented uniform spheres with rough surface. The broken nanocapsule indicated that the shell of the nanocapsule was thin and could coat more epoxy resin. The analysis of finite element method proved that nanocapsules prepared in the optimum conditions with an average of 110 nm shell thickness were suitable for self-healing materials.