In order to investigate the morphology of intumescent polyurethane (PU), X-ray tomography is used. Nano MgO was added to some of the chars as a synergist. The results of the morphology investigations were then correlated with measured thermal conductivities of PU chars over a range of temperatures. It was found that X-ray tomography was useful in observing the breakdown of chars during burning. In addition to this, adding nano MgO ...
