EVM/PLA共混发泡材料泡孔结构和性能的研究

Study on the Cell Structure and Properties of EVM/PLA Foam

以乙烯-醋酸乙烯酯橡胶(EVM)和聚乳酸(PLA)共混物为基体材料,经模压发泡制备了共混发泡材料。研究了EVM/PLA不同共混比、硫化剂(DCP)、发泡剂(AC)和白炭黑用量以及不同发泡时间对EVM/PLA共混物发泡材料泡孔结构和物理机械性能的影响。结果表明,随PLA组分的减少,白炭黑和DCP用量的增加,泡孔逐渐减小,均匀度增加,孔壁增厚,材料的密度、拉伸强度和拉断伸长率呈升高趋势,发泡倍率呈降低趋势。随发泡剂AC用量的增加,泡孔壁变薄,平均泡孔尺寸变化不大,材料的密度、拉伸强度和拉断伸长率呈降低趋势,发泡倍率增加。随硫化时间的延长,泡孔尺寸变小,孔壁增厚、发泡倍率逐渐下降,拉伸强度先增大后减少,拉断伸长率先下降后上升。

With ethylene vinyl-acetate copolymer （EVM） and polylactic acid （PLA） blends as the matrix, EVM/PLA foamed blends were prepared by compression molding. The effects of different ra tios of EVM/PLA ,different contents of the curing agent（DCP）, foaming agent（AC）, filler（silica）as well as different foaming time on cell structure and physical properties of EVM/PLA foam were stud- ied. The results showed that with the decrease of PLA or the increaase of silica and DCP, the cell size decreased, but the uniformity and the cell thickness increased, the material density and tensile strength and elongation at break increased ,foaming ratio took on a down trend. With the increase of AC, the cell thickness decreased, the average cell size changed little, the material density and the ten- sile strength and elongation at break decreased, the foaming ratio increased. With the prolongation of the foaming time, the cell size decreased, thickness increased, foaming ratio decreased gradually, the tensile strength increased first and then decreased, the elongation at break increased first and then in-creased.