三成分系統熱誘導式相分離孔洞 成長與合併之探討

Investigation on coarsening in thermally induced phase separation for ternary system

林冠宇(Guan-Yeu Lin)

指導教授 ： 賴君義

中原大學/工學院/化學工程研究所/碩士(2005年)

https://doi.org/10.6840/cycu200500309

摘要

摘要
本研究探討在Poly(DL-lactide-co-glycolide)(PLGA)與Polysulfone(PSf)之系統中，相分離後期分散相成長與合併的機制，希望能釐清在相分離過程中主導孔洞成長之因素。實驗中以光學顯微鏡觀察相分離的成長與合併，並量測高分子溶液界面張力與黏度來探討成長機制。結果顯示對PLGA系統而言，界面張力主導coarsening的速度，隨著quench depth 的增加而孔洞成長速度加快；在PSf系統而言，發現在低於critical point的組成隨著quench depth的增加其分散相的合併速度是減慢，可能是由於當相分離後高分子富相與貧相達到其平衡濃度時就已滿足介面自由能最小化的條件。發現在critical point與高於critical point 的組成，quench depth 的增加會使得高分子貧富相間的界面張力增大，也同時使得高分子富相黏度增加，界面張力增大會使孔洞成長加速，但黏度的提升則有相反的效應，兩者相互競爭。在 6 wt% PSf 高分子溶液中，當 quench depth小於 13oC時為界面張力主導，隨著quench depth的增加而合併速度加快，當quench depth大於13oC時，則為黏度主導，隨著quench depth的增加而合併速度減慢。在 9 wt% PSf 高分子溶液中則以quench depth 10oC為區分，quench depth小於10oC為界面張力主導；quench depth 大於10oC則由黏度在主導孔洞合併。

關鍵字

三成份系統 ； 孔洞成長與合併

並列摘要

In this study, the mechanisms of coarsening in the late stage of phase separation for ternary compositions of Poly(DL-lactide- co-glycolide) (PLGA)/dioxane/water and Polysulfone (PSf)/Diethyl glycol dimethyl ether (DGDE)/Ethanol systems were investigated via thermal induced phase separation (TIPS). Optical microscopy was used to observe the coarsening phenomena of phase separation and the interfacial tension between polymer rich phase and poor phase and the viscosity of polymer rich phase of polymer solution were measured to investigate the mechanism of growth. The results show that the growth rate of pore increases with increasing the quench depth for PLGA system. The coarsening rate was dominated by interfacial tension in this system. For PSf system, the interfacial tension as well as the viscosity of polymer rich phase increases with increasing the quench depth at/above the composition of critical point. The interfacial tension dominated the coarsening rate when the quench depth was lower then 13℃ or 10℃ while the coarsening rate was dominated by viscosity when the quench depth was higher then 13℃ or 10℃ in the case of 6 wt% PSf system (the composition of critical point) and 9 wt% PSf system (above the composition of critical point), respectively.

並列關鍵字

ternary ； coarsening

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