Positron Annihilation Study of Polymers Treated in Supercritical Carbon Diozide
Supercritical carbon dioxide is an environmentally friendly and efficient solvent for many polymers. Its gas-like viscosities and liquid-like densities has been utilized for e.g. inducing crystallization and crystal transitions in various polymers 1-4 and for producing polymer foams 5-7. By using WAXD to characterize the crystal state and positron annihilation lifetime spectroscopy (PALS) to analyze the free volume, we have explored the relation between treatment conditions in scCO2 and free volume changes for various polymers. Three polymer systems have been studied so far. In syndiotactic polystyrene sPS, the complex crystallization and crystal transition behaviour under scCO2 conditions has been investigated in detail. The different treatment conditions were subsequently correlated with the free volume sizes. Poly(ethylene naphtalate) PEN samples were treated in scCO2 in order to induce crystallization.
Anna Andersson Jiasong He Wentao Zhai Frans H.J.Maurer
Department of Polymer & Materials Chemistry,Lund University,SE-22100 Lund,Sweden Key Laboratory of Engineering Plastics,Joint Laboratory of Polymer Science and Materials,Institute o
国际会议
第九届国际正电子与正电子素国际会议(9th International Workshop on Positron and Positronium Chemistry)(PPC–9)
武汉
英文
20
2008-05-11（万方平台首次上网日期，不代表论文的发表时间）