利用低溫電漿技術對聚對苯二甲酸乙二酯表面改質 及增強界面接著強度之研究

Studies on poly (ethylene terephthalate)(PET) surface modification and enhancement of the interfacial fracture toughness by cold plasma techlonogy

崔岱安(Tai-An Tsui)

指導教授 ： 戴子安

國立臺灣大學/工學院/化學工程學研究所/碩士(2004年)

https://doi.org/10.6342/NTU.2004.00432

摘要

本研究是利用低溫電漿技術對高分子聚對苯二甲酸乙二酯(PET)進行表面改質，而經過不同程度氮氣電漿改質後之PET，藉由化學能譜儀(XPS)進行表面分析及與水接觸角測試的親水性實驗；經過氮氣電漿處理之PET表面會產生含氮之官能基而使表面接觸角下降，再經由對細微XPS圖譜分析可知PET表面氮元素植入比率會隨著電漿處理程度而增加，最多可達8%。另外，利用另一高分子材料PSMA(poly styrene-co-maleic anhydride)與電漿處理後之PET進行化學反應接著之研究，經過電漿處理後之PET表面生成之amine之官能基會與PSMA中maleic anhydride作用產生imide之共價鍵結，對於不同程度之電漿處理PET各樣品，在不同熱處理溫度下進行此接合反應，再利用非對稱雙懸臂界面接著測量法(ADBC)作為測量兩材料界面強度之儀器，可知在熱處理溫度為150℃時有最佳之界面加強效果產生，界面接著強度可由未處理前約3J/m2增強至超過100J/m2。
利用XPS與SEM分析破壞界面，可以得知在不同界面接著強度下之破壞機制，在溫度為150℃時在電漿處理時間超過150sec後，由於兩高分子界面強度大於PET材料本身之層狀結構破壞強度，故破壞之破裂點會延伸至PET材料內部;而在反應溫度過高時(160℃)，界面強度反而下降是因為PSMA質傳過快而在界面形成一機械強度較弱之另一界面之緣故。
最後探討了界面接著強度與areal chain density(Σ)之關係後可知，在Σ值較小時，界面強度值(Gc)與Σ2成線性關係；當Gc值超過100J/m2後，破壞機制轉變至材料內部破裂，Gc值故不再隨著Σ值上升而增大。

關鍵字

電漿技術 ； 高分子表面改質 ； 界面增強

並列摘要

Nitrogen plasma caused ion implantation and then carried out surface modification on Poly (ethylene terephthalate)(PET) efficie- ntly. With the increasing of plasma treatment time, water contact angle of treated-PET surface would decrease, finally reached a stable value, 25degree. By X-ray photoelectron spectrometer (XPS) analy- sis, atomic nitrogen content of plasma treated PET by ion implantation and bonding condition can be obtained. Furthermore, the interfacial fracture toughness (Gc) between ( poly styrene–co- maleic anhydride) (PSMA) and plasma treated-PET was had investigated.
Amine groups formed by plasma modification on the PET surface can reacts with styrene maleic anhydride (SMA) in bulk PSMA, forming imide covalent bonds to enhance interfacial fracture toughness between PET/PSMA. In our case, when annealing temperature at 150℃, the PET/PSMA is too strong to cause crack-tip propagated into PET side, the Gc values could be enhanced over 100J/m2 for long plasma treatment time. Otherwise, the diffusion rate of PSMA is too fast at annealing temperature at 160℃, causing a new weak interface occurred, and then crack-tip would propagate into PSMA side, Gc value become lower than condition 150℃. Fracture mechanisms are verified by XPS and SEM analysis of fractured PET and PSMA surface, and the results coincide with our explanation.
In our case, there are two mechanisms of PET/PSMA interface fracture. When areal chain density (Σ) on the interface is lower than 0.05/nm2, the interfacial fracture toughness (Gc) is proportional to Σ2. And at areal chain density larger than 0.05/nm2 region, the interfacial fracture toughness is independent to areal chain density, because the fracture happened in PET side.

並列關鍵字

plasma treatment ； surface modification ； interface enhancement

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