Lim Donghwan, Lee Sanghyun, Jung Seungho, Kim Kwanhoon, Hong Jin, Cha Sung Woon
Department of Mechanical Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 03722, Republic of Korea.
School of Mechanical Engineering, Sungkyunkwan University, Suwon 16419, Republic of Korea.
Polymers (Basel). 2024 Sep 26;16(19):2723. doi: 10.3390/polym16192723.
This study investigates the modeling and experimental validation of cell morphology in microcellular-foamed polycaprolactone (PCL) using supercritical carbon dioxide (scCO) as the blowing agent. The microcellular foaming process (MCP) was conducted using a solid-state batch foaming process, where PCL was saturated with scCO at 6 to 9 MPa and 313 K, followed by depressurization at a rate of -0.3 and -1 MPa/s. This study utilized the Sanchez-Lacombe equation of state and the Peng-Robinson-Stryjek-Vera equation of state to model the solubility and density of the PCL-CO mixture. Classical nucleation theory was modified and combined with numerical analysis to predict cell density, incorporating factors such as gas absorption kinetics, the role of scCO in promoting nucleation, and the impact of depressurization rate and saturation pressure on cell growth. The validity of the model was confirmed by comparing the theoretical predictions with experimental and reference data, with the cell density determined through field-emission scanning electron microscopy analysis of foamed PCL samples. This study proposes a method for predicting cell density that can be applied to various polymers, with the potential for wide-ranging applications in biomaterials and industrial settings. This research also introduces a Python-based numerical analysis tool that allows for easy calculation of solubility and cell density based on the material properties of polymers and penetrant gases, offering a practical solution for optimizing MCP conditions in different contexts.
本研究调查了以超临界二氧化碳（scCO₂）为发泡剂的微孔发泡聚己内酯（PCL）中细胞形态的建模与实验验证。微孔发泡过程（MCP）采用固态间歇发泡工艺进行，其中PCL在6至9MPa和313K下用scCO₂饱和，然后以-0.3和-1MPa/s的速率减压。本研究利用桑切斯-拉康布状态方程和彭-罗宾逊-斯特里耶克-维拉状态方程对PCL-CO₂混合物的溶解度和密度进行建模。对经典成核理论进行了修正，并与数值分析相结合，以预测泡孔密度，其中纳入了气体吸收动力学、scCO₂在促进成核中的作用以及减压速率和饱和压力对泡孔生长的影响等因素。通过将理论预测与实验数据和参考数据进行比较，证实了该模型的有效性，泡孔密度通过对发泡PCL样品的场发射扫描电子显微镜分析来确定。本研究提出了一种可应用于各种聚合物的泡孔密度预测方法，在生物材料和工业环境中具有广泛的应用潜力。本研究还引入了一种基于Python的数值分析工具，该工具可根据聚合物和渗透气体的材料特性轻松计算溶解度和泡孔密度，为在不同情况下优化MCP条件提供了一种实用的解决方案。
