The Foaming Process of Poly Styrene-co-acrylonitrile (SAN) with Co Blowing Agents

In this work, the poly styrene-co-acrylonitrile (SAN) beads and three blowing agents (CO2, N2, and n-pentane) were used to investigate the foaming process via our batch foaming system. The solubility and diffusivity of three blowing agents were determined by the AISB. The solubility of blowing agents was increased by pressure and decreased by temperature increment. It has resulted in higher solubility and diffusivity data for SAN/n-pentane/CO2 system (Using co-blowing gent) than other samples. According to the scanning electron microscopy (SEM) results, it was concluded that the cell and foam densities were decreased with temperature increment and increased by pressure release rate in all foamed beads. With using co blowing agents, higher pressure release rate, and low temperature without adding any fillers, we could improve the foam characteristics and produce the SAN foams with smaller cell sizes and greater cell and foam densities.