Cell coalescence suppressed by crosslinking structure in polypropylene microcellular foaming
作者：翟文濤, 王紅英, 余堅*, 董金勇*, 何嘉松
關鍵字：Polypropylene，foaming，microcellular
論文來源：期刊
具體來源：POLYM ENG SCI, 2008, 48:1312–1321.
發(fā)表時間：2008年
A series of crosslinked polypropylene samples with increased melt strengths were prepared via a copolymerization reaction, followed by melt processing. These crosslinked PP samples (PP-Cs) were foamed by a temperature rising process using supercritical CO2 as the physical blowing agent. The introduction of crosslinking structure resulted in PP-Cs foams with well-defined closed cell structure, decreased cell size, and increased cell density in comparison with a linear PP, which were attributed to the suppressed cell coalescence due to the significant increase in melt strength of PP-Cs. Further increasing the crosslinking degree tended to enhance the suppression effect on the cell coalescence, and hence increase the cell density of PP foams under the same foaming conditions,
especially at the longer foaming times. The welldefined closed cell structure was observed at the foaming temperature of 170–2508C and saturation pressure of 12–20 MPa.