本研究論文主要是探討聚偏二氟乙烯(PVDF)顆粒型薄膜之製備、改質及其高分子製膜液相關性質的研究，製膜液的組成為聚偏二氟乙烯(PVDF)與二甲基甲醯胺(DMF)，沉澱槽為正辛醇，藉由改變PVDF/DMF 製膜液之溶解溫度探討其對薄膜結構所造成的影響以及相關物理性質方面的檢測，如抗張強度、熱性質、結晶構造等。研究結果發現溶解溫度為50度C的製膜液所製備的薄膜其結晶顆粒大小約為400-600nm，70度C的約為1.5-2μm，90度C的約為3.5-4μm，110度C約為15-50μm，抗張強度則以溶解溫度為50度C的薄膜最強，110度C最弱，熱性質方面這4張薄膜呈現的結果是類似的，而結晶構造上這4張薄膜都是屬於α形式的結晶構造，其中又以溶解溫度為110度C所製備的薄膜最為明顯。薄膜改質是透過退火程序進行研究，以不同退火溫度觀察薄膜性質的改變，結果發現當退火溫度達到150度C，薄膜在結構上明顯有熔接及表面平坦化的情形產生，抗張強度、結晶度也有顯著的提升，在結晶構造上，薄膜經過退火後，α型態的結晶也有愈來愈明顯的趨勢。製膜液性質的研究上，可發現隨著溶解溫度的不同其形程凝膠的時間也不同，溶解溫度為50度C的製膜液約為7天，110度C的則是4個月以上，隨著靜置時間的延長，從XRD、SEM的實驗結果來看可發現晶核密度隨著靜置時間的延長會變大，造成XRD圖譜上強度的升高與SEM圖形上結晶顆利從球晶變為枝晶或從大的球形結晶顆粒變成小的球形結晶顆粒。 The effects of the dope dissolution temperature on the membrane structure and physical properties (e.g. tensile strength, thermal behavior, crystal structure, etc.) were studied. It was found that the membranes prepared by dopes dissolved at 50, 70, 90, and 110 degree C exhibited structures composed of globules with sizes being 0.4-0.6.mu.m, 1.5-2.mu.m, 3.5-4.mu.m, and 15-50.mu.m respectively. The tensile strength of the membrane prepared by 50 degree C dissolved dope was the highest while that prepared by 110 degree C dissolved dope was the lawest. The DSC thermal behaviors of all these four membranes were similar. XRD analysis showed that all membranes exhibited the alpha-crystal form; the membrane prepared by the 110 degree C dissolved dope demonsted the most obvious peaks. The membrane were post heat-treated to improve their physical properties. It was found that after annealing at 150 degree C for 1 day, the surfaces of the globules became flattened and some fusion between the globules had occurred. The mechanical strength and crystallinity of the membrane were also increased after heat treatment. And the XRD peaks were more obvious. The properties of the dopes were studied. It was found that the gelation time for dope dissolved at different temperature were also different. For the dope dissolved at 50 degree C it took 7 days to gel, where as for the dope dissolved at 110 degree C, the gelation time was more than 4 months. With increasing standing time, the extent of crystallization in the dope was increased, as revealed by the XRD intensity. The SEM micrographs for membranes prepared by dopes with different standing time indicated that the nucleation density was increased during the standing process; as was evident that the size of the large globules in the membranes were reduced and the small globules became sheet or stick-like crystals.
