Compression Molding of Thermoplastic Polyurethane Foam Sheets with Beads Expanded by Supercritical CO2 Foaming

Polymers

Ho-Jong Kang¹  Tao Zhang¹  Yong Hwan Yoo²  Seung-Jun Lee²  Kyu-Hwan Park² 

[1] Department of Polymer Science and Engineering, Dankook University, 152 Jukjeon-ro, Suji-gu, Yongin-si, Gyeonggi-do 16889, Korea;HDC Hyundai EP R&D Center, 603 Graduate Schools Bldg., Dankook University, 152 Jukjeon-ro, Suji-gu, Yongin-si, Gyeonggi-do 16889, Korea;

关键词: thermoplastic polyurethane;    expanded bead;    supercritical CO₂ foaming;    expansion ratio;    resilience;    hardness;   

DOI  :  10.3390/polym13040656

来源: DOAJ

【 摘 要 】

Expanded thermoplastic polyurethane (ETPU) beads were prepared by a supercritical CO₂ foaming process and compression molded to manufacture foam sheets. The effect of the cell structure of the foamed beads on the properties of the foam sheets was studied. Higher foaming pressure resulted in a greater number of cells and thus, smaller cell size, while increasing the foaming temperature at a fixed pressure lowered the viscosity to result in fewer cells and a larger cell size, increasing the expansion ratio of the ETPU. Although the processing window in which the cell structure of the ETPU beads can be maintained was very limited compared to that of steam chest molding, compression molding of ETPU beads to produce foam sheets was possible by controlling the compression pressure and temperature to obtain sintering of the bead surfaces. Properties of the foam sheets are influenced by the expansion ratio of the beads and the increase in the expansion ratio increased the foam resilience, decreased the hardness, and increased the tensile strength and elongation at break.

【 授权许可】

Unknown