Influence of the irradiation dose in the cellular structure of naturalrubber foams cross-linked by electron beam irradiation

Abstract

tThis work focused on the production of natural rubber foams by cross-linking the polymer matrix usinghigh energy electron beam at different irradiation doses (from 50 to 150 kGy) and foaming it with achemical blowing agent. The aim was to study how the irradiation dose influenced the cellular structuremorphology of the produced foams. This was accomplished by quantifying the evolution of cellular struc-ture parameters, such as cell size and cell density, with respect to foaming time and irradiation dose. Theresults showed that the foams irradiated at the lowest dose are more prone to suffer cellular structuredegeneration, resulting in the formation of bimodal cellular structures, while foams irradiated with thehighest dose, exhibited more uniform cellular structure. In the latter case, the nucleation density clearlyincreased resulting in the formation of foams with homogeneous cellular structures and smaller cell sizes(≈20 microns).