Study On Preparation Of POE,Engage And EPM Modified LDPE Foaming Materials And Physical And Mechanical Properties

The modified LDPE foam materials comprising LDPE as matrix material, ethylene-octene copolymer (POE), ethylene-butene copolymer (Engage), or ethylene propylene rubber (EPM) as toughening materials, CaCO3 as reinforcing filler, which was modified by interfacial modifier such as borate, stearic acid monoglyceride and oleamide were prepared following the procedures of interface modification, toughening, mixing plasticizing, twin-roll mixing, curing and foaming. The interface modification effects of CaCO3 were evaluated by FT-IR and hygroscopic property. The dispersion of modified CaCO3 in LDPE matrix material and its impact on the material bubble hole were analyzed by scanning electron microscopy (SEM). The influence of the amount of POE, Engage, EPM, DCP, and AC on foaming pressure, torque value, mechanical properties, and bubble-shaped of the LDPE foam material were discussed, the kinetics of vulcanization and crosslinking reaction were investigated, and the mechanical properties were also measured.The results showed that new absorption peaks appeared at 2850 and 1324 cm-1 in infrared spectrum of CaCO3 modified by borate (1.25%wt); the "sea-island" two-phase structure was formed as the POE separated in the LDPE matrix. The torque value of the LDPE foaming materials with 40 phr POE increased in foaming processing, and this foamed material had uniform bubble holes, excellent physical and mechanical properties. When Engage was 30 phr in LDPE, the torque value of LDPE/Engage foaming material was higher; the foam bubble hole was bigger but uniform. With the EPM was increased, LDPE/EPM's torque value was increased, foaming time was delayed. The melt strength of the LDPE/EPM foaming materials with 20 phr EPM was enhanced, and the foam pressure became higher, foam bubble hole became more uniform. After formula and technology were optimized, the physical and mechanical properties of the modified LDPE foam materials were excellent, cost was moderate. The results can provide a new method to make the modified LDPE foam materials.