工艺温度对超临界CO2发泡聚丙烯泡孔结构的影响  

Effect of Foaming Temperature on Cell Structure of Foamed Polypropylene Using Supercritical CO_2

作　　者：张壮[1] 许治昕[1] 郑安呐[1] 管涌[1] 

机构地区：[1]华东理工大学材料科学与工程学院,超细材料制备与应用教育部重点实验室,上海200237

出　　处：《华东理工大学学报（自然科学版）》2010年第5期655-661,共7页Journal of East China University of Science and Technology

基　　金：国家自然科学基金(50573020)

摘　　要：以自制的高熔体强度聚丙烯为原料,利用超临界流体技术制备了聚丙烯发泡材料。重点考察了发泡温度对所得聚丙烯泡孔结构的影响。结果表明：155-170℃为适宜发泡的温度区间,随着温度的降低,泡孔密度增加,平均泡孔直径减小;当发泡温度为160℃时,泡孔密度、平均泡孔直径和表观密度依次分别为1.03×107cell/cm3、73.86μm和0.016 g/cm3,此时发泡倍率最大,达到55倍;温度通过影响聚丙烯的结晶速率、熔体的黏弹性以及发泡剂在聚丙烯熔体中的溶解度和扩散系数等来控制泡孔结构和发泡倍率。The foamed PP was prepared by using supercritical CO_2 with self-made high melt-strength polypropylene as starting material.Effect of foaming temperature on cell structure was studied.The results indicate that a suitable foaming temperature zone,from 155 ℃ to 170 ℃,was gained.Cell density increases gradually with the decreasing of foaming temperature,while average cell diameter changes along the opposite trend.When the foaming temperature is 160 ℃,cell density,average cell diameter and apparent density are 1.03×107 cell/cm3, 73.86 μm and 0.016 g/cm3 respectively.Furthermore,foam expansion ratio reached the largest,about 55 times.Foaming temperature controlled the cell structure and foam expansion ratio by influencing the crystallization rate,viscoelasticity as well as the solubility and diffusivity of the blowing agents in the polypropylene melt.

关 键 词：超临界CO2 聚丙烯 发泡 泡孔结构 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]