influence of phase ratio upon cellular structure and compressive stress-strain behavior of crosslinked ldpe/eva foams

In the present work, the influence of phase ratio upon cellular strucutre and compression behavior of crosslinked foams based on blend of low-density polyethylene (ldpe) and ethylene-vinyl acetate copolymer (eva) have been studied. for this purpose, blend compounds with phase ratios (90/10, 70/30 and 50/50) from ld-rich and eva-rich containing dicumyl peroxide (dcp) and azodicarbonamide (adc) as crosslinking and foaming agent respectively prepared via melt mixing, and thereafter foaming was conducted in one-step compression molding. eva-rich foams revealed higher gel content and cell density in compared to ld-rich counterparts due to the higher crosslinking effeciency of eva than ldpe. as per scanning-electron-microscopy (sem) analysis, eva-rich foams (phase ratio 90/10) demonstrated much higher cell density and lower cell diameter compared with similar ld-rich foam. compressive stress-strain test exhibited lower mechanical hysteresis for ld-rich foams increasing eva level, as a result of more rubbery-effect of eva on the cell walls and also decrease in ldpe crystallinity. this led to the increase of strain recovery behavior of ld-rich foams with eva content.