Dimensional stability analysis of foams based on LDPE and ethylene-styrene interpolymer blends

This study extends our earlier work on the fundamental aspects of modeling on foam aging and dimensional stability. The thickness change of extruded polyolefin foam to the blowing agent and air counter diffusion during the postextrusion aging process is modeled. The blowing agent and air counter diffusion equations are coupled with more complicated Maxwell-Voigt four-parameter viscoelastic equations to model the foam dimensional change and recovery processes. The effects of blending ethylene-styrene interpolymer resin and adding aging modifier are investigated, respectively and altogether. The mathematical model is also compared with experimental data.