Síntese de microcápsulas de Poli(ureiaformaldeído)(PUF)/Diciclopentadieno (DCPD): Influência do tipo de agitação e sua incorporação em matriz epóxi

Abstract

The use of microcapsules has been studied to promote the self-healing functionality in polymers and polymer matrix composites. Variation in the synthesis parameters, such as speed and type of agitation, can alter the properties of the microcapsule walls. The microcapsule walls must withstand during processing, but they should break easily, releasing then the encapsulated liquid, upon an inflicted damage. In this work, poly (urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) were synthesized using two types of stirring: magnetic and mechanical stirring. The synthesized microcapsules were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). The characterizations showed that DCPD microcapsules were successfully synthesized, and that mechanical stirring produced finer and more dispersed microcapsules. The microcapsules were embedded in epoxy specimens to evaluate its dispersion and distribution. Scratches were made on the surface of the samples in order to observe the self-healing effect, and it was observed that there was no self-healing effect in the damaged region. Bending tests were also performed to evaluate the effect of the microcapsule and Grubbs catalyst addition on the flexural properties of the polymer resin, and showed that the addition of particles causes significant effects on the mechanical properties. The effect of accelerated aging on neat and modified epoxy samples at 90 ° C was also evaluated, and showed influence on the mechanical properties of the material.