Calculating diffusion coefficients from molecular dynamics simulations for foam extrusion modelling of polypropylene with CO<sub>2</sub>, N<sub>2</sub> and ethanol
نویسندگان
چکیده
In foaming processes, the blowing agent has a significant influence on material behaviour and necessary processing parameters. Low-density polypropylene foam sheets are usually produced with aliphatic hydrocarbons or alkanes as physical agent. Due to safety precautions environmental impact, there is great interest in using alternative agents such CO 2 . The sole use of often leads corrugation, open cells surface defects sheet therefore requires modifications process technology. For this reason, mixtures based organic solvents used for production sheets. developing model describing melt flow extrusion die formation cells, specific data like diffusion coefficients necessary. N agent, experimental exist literature. Since no available co-blowing ethanol at elevated temperatures they occur process, these were calculated molecular dynamics (MD) simulations. benefit MD simulations lies their ability reduce effort and, particular, provide cases where not through measurements. coefficient values compared from literature presented , polypropylene. results agree well them. molecules, relative both aforementioned ones considered larger size molecule reasonable found other two molecules.
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ژورنال
عنوان ژورنال: Journal of Cellular Plastics
سال: 2022
ISSN: ['0021-955X', '1530-7999']
DOI: https://doi.org/10.1177/0021955x221087598