Improving the mechanical properties of polymers by adding self-healing capabilities

The addition of self-healing capabilities to polymers through the dispersion of First Generation Grubbs' Catalyst (FGGC) and poly(urea-formaldehyde) (PUF) microcapsules filled with dicyclopentadiene (DCPD) as the healing agent, has been investigated by various experimental techniques such as Optical microscopy, Scanning Electron Microscopy, Tensile tests, Raman Spectroscopy, and Themogravimmetric Analysis (TGA). Optical and Scanning Electron Microscopy revealed the morphology of the surface of the PUF microcapsules, the diameter size distribution and the thickness of the shell, and their structure when dispersed in the polymeric matrices. Photos taken after the tensile test showed broken microcapsules on both polymer matrices having released the DCPD content. Self-healing capabilities added to polyethylene oxide (PEO) and polystyrene-block-poly-isoprene- block-polystyrene (PS-PI-PS) were confirmed by mechanical testing. An improvement of 28% for PEO and 11% for PS-PI-PS was observed. Raman Spectroscopy confirmed the confinement of DCPD in the PUF microcapsules as well as the polymerization kinetics of the self-healing polymer samples for both polymer matrices (PEO and PS-PI-PS). TGA data revealed the mass loss and the mass loss rate changes for the PUF microcapsules.