Effects of fluorinated silane compound on the repeated self- healing properties of nanocapsules

Urea-formaldehyde (UF) nanocapsules, used as self-healing materials, were prepared by in situ polymerization. Fluorinated silane compound KBM7803 was used to modify the surface of the UF nanocapsules. OM and SEM images exhibited the uniform distribution of nanocapsules without any agglomeration when the amount of KBM7803 was less than 2 %. FT-IR of nanocapsules indicated KBM7803 was easily absorbed on the surface of nanocapsules. The evaluation of thermal stability and mechanical properties revealed that addition of KBM7803 significantly improved the thermal stability, tensile strength, and elastic property. Evaluation of self-healing efficiency indicated when the amount of KBM7803 was 2 %, the material exhibited up to 58.9 and 53.6 % of the first and second self-healing efficiency. XPS indicates that F1s can self migrate to the surface of the cracks which guarantees it can be used as self-healing materials to achieve the repeated self healing property.