|摘要: ||本研究係探討在不同質傳溫度(40℃~60℃)下，聚甲基丙烯酸甲酯於不同濃度之氯化錫/甲醇潛溶劑(0g/100g、3g/100g、5g/100g、7g/100g及9g/100g)中的質傳及水解行為，並利用成功製得之聚甲基丙烯酸甲酯/二氧化錫奈米複合材料，進一步探討奈米複合材料之光學性質、機械性質及熱性質。實驗結果顯示，潛溶劑之飽和吸收量，隨質傳溫度增加而上升； Case Ⅰ擴散之擴散係數與Case Ⅱ擴散之擴散速率隨潛溶劑濃度增加而減少；質傳過程為吸熱反應；Case I擴散活化能隨潛溶劑濃度的增加而減少而Case II的擴散活化能隨潛溶劑濃度的增加而增加。吸收飽和溶劑之聚甲基丙烯酸甲酯，在去離子水中進行水與甲醇之溶劑擴散交換時，當聚甲基丙烯酸甲酯的玻璃轉換溫度大於水解溫度時，其重量損失即趨於緩慢解析。經XRD分析，複合材料中二氧化錫之波峰強度隨潛溶劑濃度與質傳溫度之增加越趨明顯；SEM觀察則發現，二氧化錫顆粒析出物係均勻分佈於基材內，且析出物的含量隨潛溶劑濃度增加而增加，析出物的尺寸約30-50nm。經由可見光及紫外光穿透光譜分析，發現其穿透率隨質傳溫度及氯化錫/甲醇潛溶劑濃度增加而下降，且截止波長有往長波長移動(紅移)的現象；經紅外光光譜分析，析出的二氧化錫顆粒與PMMA並沒有明顯的界面鍵結，故並無新的吸收峰出現，波形改變不明顯。此外，複合材料之抗拉強度及伸長率隨潛溶劑濃度增加而減少，且隨質傳溫度上升而遞減；而脆性拉伸破壞面型態比率、硬度(Hs)及玻璃轉換溫度(Tg)，則隨質傳溫度及潛溶劑濃度增加而上升。|
The study investigats the mass transport and hydrolysis behavior for poly (methyl methacrylate) (PMMA) in various concentrations of methanol/ tin chloride (SnCl2•2H2O) cosolvent between 40℃ to 60℃. Furthermore, by using the successfully manufactured poly (methyl methacrylate)/ tin dioxide nano composites, the mechanical, optical and thermal properties are investigated. The experiment data reveals that the concentration of SnCl2•2H2O to methanol in the solvent mixture is X＝0, 0.03, 0.05, 0.07 and 0.09g/g and the saturated absorption amount of cosolvent will increase by rising mass transport temperature. Both diffusion coefficient for Case I and diffusion velocity for Case II will decrease with increasing concentration of cosolvent X. The activation energy of diffusion coefficient in Case I transport decreases with increasing X, but the activation energy of diffusion coefficient in Case II transport is opposite. The mass transport process is endothermic and satisfies the van’t Hoff’s plot.
When PMMA with saturated solvent mixture carries out the diffusion exchange between water and methanol solvent in distilled water system as well as the glass transition temperature of PMMA is higher than the hydrolysis temperature, the weight loss namely tends to slowly resolved.
Through XRD analysis, as the temperature of cosolvent and mass transport goes up, the wave peak intensify of tin dioxide becomes more obvious. By means of SEM, tin dioxide particulates are found evenly distributed on the matrix and the quantity of particulates become higher with the increasing cosolvent concentration. The size of particulates is about 30-50nm. Through visible wavelength and the UV spectrum analysis, the transmittance is found declined as the mass transport and the cosolvent concentration increases and the cut-off wavelength tends to shift to long wavelength (red shift).
The FTIR spectrum analysis shows that tin dioxide particulates and PMMA has no obvious surface bonding. Therefore, no new absorption peak is found and so do the change shown on the wave shape. In addition, both the UTS (Ultimate Tensile Strength) and the elongation ratio of the composites go down with the increasing cosolvent concentration and the uprising mass transport temperature. However, the ratio of brittleness fracture surface morphology, Shore Hardness (Hs) and the glass transition temperature (Tg) will go up with the increasing cosolvent concentration and the uprising mass transport temperature.