Effects of surface modification on the properties of microcapsules for self-healing

Abstract

Poly (urea-formaldehyde) (UF) microcapsules with epoxy resin E-51 as core material used as self-healing materials were prepared by interfacial polymerization method. The surface of UF microcapsules was modified by γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH-560). The interfacial interactions between UF microcapsules and KH-560 were studied by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectrometric analysis (XPS) of microcapsules. The surface topography of microcapsules was characterized by scanning electron microscopy (SEM). The thermal stability and mechanical properties were evaluated. FTIR and XPS results showed that there were physical and chemical combinations between the silicon coupling agent and the microcapsules surface. The thermal stability and mechanical property analysis showed that the addition of KH-560 could greatly improve the thermal stability, tensile property and elastic property. SEM results indicated that the addition of KH-560 could improve the bonding between the surface of microcapsules and resin matrix and improve the ability of self-healing.