Preparation And Characterization Of Modified Starch/EVA Environmental Friendly Composite Foamed Sole Materials

In this paper, a new kind of environmental friendly EVA foam sole materials was studied and prepared. Through the L9(34) orthogonal experiment, the effects of glycerin as plasticizer, ethylene acrylic acid copolymer (EAA) as solubilizer, ethylene-octene copolymer (POE) as elastomer and talc on the mechanical properties of starch/EVA composite foamed sole materials were investigated. Furthermore, the effects of tapioca starch, corn starch, AC, DCP and talc on the mechanical properties was also researched. The FT-IR showed that the adsorption peak at 3360 cm-1 became weaker and wider, which indicated glycerin damaged and weakened the hydrogen bond between the intermolecular of starch.The tapioca starch/EVA composite foamed sole materials had the best comprehensive mechanical properties when blended with 20 phr of 8003 resign,30 phr of EAA and 8 phr of glycerin while the corn starch/EVA composite foamed sole materials had the best comprehensive mechanical properties when blended with 20 phr of 8003 resign,30 phr of EAA,10 phr of talc and 8 phr of glycerin. SEM showed that the addition of EAA could reduce the amount of particles and holes on the crossing surface of tapioca starch or corn starch/EVA composite foaming precursor which indicated that EAA could improve the compatibility between starch and EVA.Nano inorganic could be induced as nucleating agents in order to accelerating bubble nucleation and cell growth in the foaming process. In this paper, kaolin was modified with silane coupling agent KH-550 and silane coupling agent KH-570, then starch/EVA composite foams with various content of modified kaolin were prepared. The effect and structure of the modified kaolin were analyzed by activation index and FT-IR. The mechanical properties and microscopic morphology of starch/EVA/modified kaolin foams were also studied. According to the results, the modified effect of silane coupling agent KH-570 was better than silane coupling agent KH-550. When 1.8phr silane coupling agent KH-570 modified kaolin, the activation index of calcined kaolin, longyan calcined kaolin and washed kaolin was 100%,100% and 99%, respectively. The FT-IR showed that silane coupling agent could make the surface of kaolin organic while XRD analysis showed that silane coupling agent could not change the crystal structure of kaolin. The optimum content of modified kaolin in starch/EVA foamed sole materials was 20phr calcined kaolin, 10phr longyan calcined kaolin and 20 washed kaolin respectively.The wet and dry grafting methods were induced to modify soluble starch and corn starch and the grafted starch was applied to EVA foamed sole materials. The formula technology of grafted starch/EVA composite foamed sole material was also investigated preliminary. The grafted starch was analyzed by FT-IR, the grafting rate and the grafting efficiency while the mechanical properties, microscopic morphology and thermal analysis of the grafted starch/EVA foams were also studied.