聚苯乙烯高分子纖維於聚乙烯醇高分子膜上進行熱退火處理之形貌變化研究

Abstract

電紡織技術可以快速且大量的製作高分子纖維，在第一個部分的研究中，我們使用電紡織技術製作聚苯乙烯高分子纖維並探討其在聚乙烯醇高分子膜上進行熱退火處理的形貌變化。經過熱處理後聚苯乙烯高分子纖維會因為雷利不穩定效應而斷裂成數顆高分子微球，由於表面能的差異，得到的會是異向性高分子微球。可透過選擇性移除來觀測熱退火處理後的高分子微球以及高分子膜的形貌。 在第二個部分的研究中，我們利用溶液退火法後處理高分子。熱退火是藉由將溫度提高到高於高分子的玻璃轉移溫度使高分子具有流動性，使高分子的形貌產生變化，但是在高溫處理下高分子可能發生熱裂解。溶劑退火是使用溶劑蒸氣膨潤高分子使之具有流動性，在室溫下進行後處理，但是溶劑退火所需的時間較長，後處理時間動輒數小時到數十小時。溶液退火可在室溫下進行、退火時間適中且可控參數多，可針對不同種類的高分子調整使用的溶劑與非溶劑。

Electrospinng is a simple technique to fabricate large amounts of polymer fibers rapidly. In the first part of this thesis, we fabricate polystyrene (PS) fibers by electrospinning and study their morphology transformation on poly (vinyl alcohol) (PVA) films using thermal annealing. Because of the effect of Rayleigh instability, PS fiber breaks into several PS particles which align regularly. The asymmetric shapes of the PS particles are related to the surface and interfacial tensions of the polymers during thermal annealing. The morphologies of the transformed PS particles are controlled by the annealing conditions. Selective removal processes are also used to confirm the morphologies of the transformed structures. In the second part, we use solution annealing as a post-treatment method to control the morphologies of polymer fibers and polymer films. Thermal annealing is to increase the mobility of polymer chain by raising the annealing temperature and the morphologies of polymers can change. But there is a problem of thermal degradation of polymers at high temperatures. Solvent annealing is another method by swelling the polymers using solvent vapors. The processing time for solvent annealing, however, is usually too long. Different from thermal annealing and solvent annealing, good-solvent and non-solvent ratio is controlled in the solution annealing method. In the solution annealing system, good-solvent swells the polymer structure and non-solvent stabilizes the polymer structure. The solution annealing method can be applied to control the morphologies of different types of polymers.