Effects of surface modification on properties of nanocapsules for self-healing materials

Urea formaldehyde (UF) nanocapsules used as self-healing materials were prepared by interfacial polymerisation method using modified aliphatic amine (HB-1618) and UF resin as core and shell materials respectively. Silane coupling agent KH560 was used to modify the surface of UF nanocapsules. Fourier transform infrared spectra (FTIR) results indicated the core materials had been successfully encapsulated in UF shell; moreover, physical or chemical combinations were observed between the surface of nanocapsules and KH560. The analyses of thermal stability and mechanical properties revealed that addition of KH560 significantly improved the thermal stability, tensile strength and elastic property. Scanning electron microscope (SEM) results indicated that the addition of KH560 led to an excellent interfacial adhesion between the surface of nanocapsules and resin matrix, thus improving the ability of self-healing, beneficial for high levels of healing efficiency in the matrix materials.