morphology and property of closed cell rubber foams

In this study, parameters related to closed cell rubber foam prepared from solid rubber have been studied. It is revealed that two kind of parameters including a)processing parameters such as pre-cure temperature and time, foaming temperature, pressure and time, b) formulation parameters such as rubber, curing agent, fillers, foaming agent type and their content control the properties of foam effecting morphology and microstructure of it. The hardness and modulus of the foam inversely depends on the expansion of foam cells. In the other words, decrease in cell size leads to increase in modulus, hardness, foam density and cellular thickness. The increase in pre-curing temperature, pre-curing time, foaming pressure, the content of filler and curing agent increase the foam density while they illustrate the inverse effect on cellular size. In addition, increase of foaming agent content and foaming temperature decrease the density of foam while increase the cell size. It is observed that increasing the cure rate of rubber foams significantly increases the modulus of the foams which is the direct result of increased density and decreased cell size.