聚酯超临界挤出发泡系统中复杂通道内的热质传递过程数值模拟与调控

项目名称： 聚酯超临界挤出发泡系统中复杂通道内的热质传递过程数值模拟与调控

项目编号： No.21306043

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 化学工业

项目作者： 奚桢浩

作者单位： 华东理工大学

项目金额： 24万元

中文摘要： 超临界挤出发泡过程中聚合物/超临界流体复杂系统的流变行为、相际传递行为以及流场分布等均会影响聚合物泡孔结构与分布，从而影响泡沫材料性能。本项目针对高熔体强度PET挤出发泡过程，研究超临界CO2/PET复杂系统流变行为基础上，构建超临界CO2在PET熔体中的溶解-扩散模型，并采用新的有限元技术对挤出发泡过程中复杂通道内PET/CO2流体流动、热质传递以及气泡均相成核-生长过程实现数值模拟，研究超临界环境下复杂流场分布规律及相际混合-分散传递行为，获得挤出发泡过程气液混合-分散、热质传递及气泡成核-生长的调控手段，以实现挤出发泡制品泡孔结构和分布可调控。研究从聚合物流变学和传递过程基本理论出发，建立非常规条件下聚合物本构方程和传递过程理论模型，以数值模拟方法研究复杂相际传递过程机理与调控手段，研究结果对形成超临界PET挤出发泡新技术有重要理论和实际意义，可为其他聚合物超临界加工提供理论基础。

中文关键词： 聚对苯二甲酸乙二醇酯；超临界二氧化碳；挤出发泡；热质传递；数值模拟

英文摘要： Processing of foamed poly(ethylene terephthalate) (PET) through extrusion foaming process by using supercritical carbon dioxide (ScCO2) is a green foaming technology. The interaction between supercritical fluid and polymer and the interphase transfer behavior in the process, which are insufficient due to the harsh environment, play an important role in determining the cell nucleation and growth and therefore, the properties of the foams. In this project, numerical simulation of complex flow field the hybrid finite element method is to be applied to study the interphase transfer behavior in the extrusion foaming process of PET with ScCO2. The dissolubility, plasticization and diffusion behaviors of ScCO2 on m-PET melt film are to be fully investigated with Magnetic Suspension Balances(MSB) and Differential Scanning Calorimetry (DSC), and the transfer process model for interface coupled with melt bulk under supercritical conditions is to be established. The constitutive equation that applied to the ScCO2/PET complex system is also to be obtained by study of rheological properties of the mixed fluids under saturated and oversaturated status. Then the complex flow field and the dispersion- distribution of ScCO2/PET complex system in mixing and conveying sections of extruder is to be simulated by coupling with gover

英文关键词： poly(ethylene terephthalate)；supercritical carbon dioxide；extrusion foaming；heat and mass transfer；numerical simulation of flow field