聚苯乙烯和聚丙烯发泡过程的泡孔生长理论

Theory Research of Bubble Inflation in Polystyrene and Polypropylene Foaming Process

采用自行推导的基于3种不同本构方程的泡孔生长模型计算结果与实验数据进行对比:Dewitt模型与气泡生长的实际情况最为吻合,然后以Dewitt模型基础理论研究了PS/CO2体系和PP/CO2体系的气泡生长过程。其中温度对于PS/CO2体系气泡生长的影响比较缓和,而PP/CO2体系的发泡过程则对温度的变化非常敏感。在相同温度下PP/CO2体系相比于PS/CO2体系来说,气泡生长速率更快,最终得到的气泡半径也更大。

Using cell model as the physical model, and deduced three kinds of bubble growth mathematical model which based on three kinds of different constitutive equation. After comparing the computer simulation of these three models with the previous experimental data,it was found that Dewitt model had more similar situation with the real bubble growth than other model. Dewitt model were used to simulate the bubble growth process in PS/CO2and PP/CO2 system. It was found that temperature had little influence for foaming in PS/CO2 system, while in PP/CO2 system temperature played a very important role in foaming. Under the same temperature,the bubbles in PP/CO2 system growed much faster than that in PS/CO2 system, and the final bubble radius simulated by computer in PP/CO2 system was also bigger than that in PS/CO2 system.