Synergistic Effect of 1-Dodecyl-3-methylimidazolium Hexafluorophosphate Ionic Liquid and Montmorillonite on Microcellular Foaming Behavior of Poly(methyl methacrylate) by Supercritical CO2

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• 作者：Hong Xu ; Fangfang Tong ; Jian Yu ; Lixiong Wen ; Jun Zhang ; Jiasong He
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2013
• 出版时间：August 28, 2013
• 年：2013
• 卷：52
• 期：34
• 页码：11988-11995
• 全文大小：427K
• 年卷期：v.52,no.34(August 28, 2013)
• ISSN：1520-5045

文摘

Poly(methyl methacrylate) (PMMA) and sodium montmorillonite (Na-MMT) were melt-blended with 1-dodecyl-3-methylimidazolium hexafluorophosphate (C₁₂mimPF₆) to prepare nanocomposites containing well-dispersed MMT layers in nanoscale and freely existed excess C₁₂mimPF₆. A synergistic effect of MMT and C₁₂mimPF₆ on the foaming behavior of nanocomposites was revealed in this study. At the mild conditions of 17 MPa and 35 掳C, neat PMMA and PMMA/C₁₂mimPF₆ and PMMA/Na-MMT samples were not foamed, while cells were induced in nanocomposites containing a certain amount of free C₁₂mimPF₆. At 25 MPa/90 掳C, foamed nanocomposites exhibited higher nucleation efficiency and cell density, and smaller cell sizes with narrower size distribution than that of neat PMMA and those binary samples. The results indicated that the MMT nanoparticles produced heterogeneous nucleation, and increased the modulus of polymer matrix to depress cell coalescence. The presence of free C₁₂mimPF₆ decreased the energy barrier for cell nucleation and facilitated the dispersion of MMT nanoparticles via in situ organic modification.