聚丙烯/CO_2微孔发泡气泡长大过程的数值模拟  

Numerical Simulation of Bubble Growth in Microcellular Foaming of PP/CO_2 System

作　　者：严庆光[1] 范金[1] 千承辉[2] 

机构地区：[1]吉林大学材料科学与工程学院 [2]吉林大学仪器科学与电气工程学院,吉林长春130022

出　　处：《高分子材料科学与工程》2013年第4期169-172,177,共5页Polymer Materials Science & Engineering

基　　金：吉林省人才资助项目(20102048);吉林大学基本科研业务费项目(20090312)

摘　　要：假设聚丙烯/超临界CO2微孔发泡气泡长大为等温过程,结合动量方程、质量方程、扩散方程以及本构方程建立了气泡长大问题的数学模型。利用可视化间歇发泡实验结果对模型进行了验证,研究了初始气泡大小、形核密度、饱和压力、压强降速率和聚合物粘弹性对气泡长大的影响。结果表明,形核密度的增加、饱和压力和压强降的降低都会阻碍气泡的长大。当松弛时间足够短时,气泡长大速度回减慢,而且在后期气泡会发生收缩。气泡初始大小对气泡初始长大过程有影响,但和最终平衡值无关。Based on momentum equation, mass equation, diffusion equation and constitutive equation, a mathematical model was established for the bubble growth in microcellular foaming of PP/CO2 system. The model was validated by comparing the simulation results with experiment data obtained from visual observations of the batch foaming system. The effects of rheological and processing parameters on the bubble growth dynamics were investigated by a series of sensitivity studies. The results demonstrate that the increase of bubble nucleus population density, the reductions of saturation pressure, and pressure release rate retard the growth of bubble. When the relaxation time is sufficiently short, the bubble will expand more slowly and contract at the late stage of the bubble growth. The increase of the size of initial bubble slows down the early bubble growth, but has no influence on the equilibrium size.

关 键 词：高聚物工业 微孔发泡 气泡长大 数值模拟 

分 类 号：TQ325.14[化学工程—合成树脂塑料工业]