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Please use this identifier to cite or link to this item: http://ir.lib.nthu.edu.tw/handle/987654321/33057

題名: 矽氧烷/聚胺基甲酸酯薄膜材料之表面性質、電氣性質、熱性質與機械性質研究及其在表面電荷消散方面的應用
其他題名: Study on the synthesis,physical and electrical properties of Siloxane/Poly(urea-urethane) and their applications on the ESD.
作者: 謝仁傑
Hsieh Jen-Chieh
摘要: 本研究旨在合成以Siloxane(及其衍生物)為軟鏈段(Soft segment)之prepolymer,並利用各種含有陰離子基團、陽離子基團、極性非離子基團等側基官能基之鏈延長劑(chain extender),合成本質型抗靜電材料。再利用薄膜表面極性分佈差異的特殊性質使硬鏈段與siloxane軟鏈段聚集(Accumulation)於材料的兩不同表面,使薄膜表面極性分佈不平均而增強表面抗靜電能力,並討論其表面性質、機械性質。 本研究主要是以prepolymer process 合成出一系列含有不同側鏈極性官能基的鏈延長劑之PDMS based Poly(urea- urethane) (PUU)薄膜材料,再對此高分子材料進行一系列的表面性質測試。其中反應檢測是利用FT-IR對NCO group拉伸吸收峰以及CO拉伸吸收峰的變化來進行。 在表面性質研究部分,由於所製備之PUU薄膜材料之兩面具有特殊的性質差異,因此利用表面水接觸角來對薄膜材料進行表面親水性及疏水性研究,利用XPS來分析表面元素分佈的情況,以SEM來觀察PUU薄膜材料表面型態學,再利用AFM來比較表面粗糙度。表面水接觸角的研究結果顯示薄膜兩面的水接觸角隨著硬鏈段比例的增加差異越大。由於軟鏈段大部分集中於空氣接觸面,而硬鏈段集中於鋁箔接觸面。因此空氣接觸面的表面水接觸角隨著硬鏈段含量的增加幾乎不變,而鋁箔接觸面的表面水接觸角則隨著硬鏈段含量的提高有顯著的增加。 由ESCA表面元素分析發現薄膜的空氣接觸面上所含的氮含量少而矽含量多,且氮/矽含量比隨著硬鏈段含量提升改變不大。然而在鋁箔接觸面上則氮/矽含量比隨著硬鏈段含量增加而有顯著地升高,且其比值明顯的比空氣接觸面上大很多。 經由SEM的microphotograph可觀察到薄膜的空氣接觸面幾乎成一homogeneous的phase,而鋁箔接觸面則隨著硬鏈段的增加而有類似cluster以及aggregation的型態出現,推論此型態的形成是由於軟鏈段的chain folding以及硬鏈段在鋁箔接觸面上的堆疊所造成。研究結果也顯示利用不同的鏈延長劑所製備的PUU會有不同的表面堆疊型態出現。 在AFM的研究中顯示空氣接觸面上的平均粗糙度相對於鋁箔接觸面上的平均粗糙度大很多,且由其剖面圖分析來觀察可以發現到以ethylene glycol及glycerol為chain extender者具有較多鋸齒狀小突起,而以DMPA為chain extender者則無鋸齒狀起伏,而是較大範圍的起伏。比較SEM microphotograph與AFM之3D topography 顯示出不同的chain extender所造成的表面起伏型態與SEM所拍攝而得之表面堆疊型態相當類似,因此可以推論PUU表面硬鏈段的堆疊方式是造成其表面型態的主要因素。 在表面電氣阻抗的研究,本研究利用PUU薄膜材料特殊的表面性質來探討其在不同相對濕度下的表面阻抗值,研究結果發現PUU薄膜材料表面阻抗值在完全乾燥的處理後高達5 ×1014 Ω,而經由70%、85%、100% R.H.的處理後表面阻抗值則可下降至108 Ω 左右,此範圍的表面導電度數值可在高濕度( 85 % ~ 100 % )的環境下作為antistatic 及ESD範圍內的應用。 PUU之機械性質的研究,可經由不同軟硬鏈段比例的調控而得之,PUU薄膜材料的tensile strength分佈由0.2Mpa至8MPa,Elongation則由20%到900%不等,而tensile modulus的分佈則是由2MPa至130 MPa。造成此現象的主因是由於隨著硬鏈段含量的提高,PUU薄膜材料具有氫鍵部分的比例也隨之提高。由於氫鍵提供了高分子鏈段間強大的作用力,因此材料本身的抗張強度以及剛性都會因為材料中氫鍵含量的提高而增強。然而也由於強大的氫鍵作用力影響,材料的伸長量也會因此而大幅度降低。所以隨著硬鏈段比例的提高,tensile strength及tensile modulus皆會有明顯上升的趨勢,而Elongation則會有明顯下降的趨勢。 由熱性質的研究可發現PUU薄膜熱裂解的溫度約在270~290 oC的區間內,其中Chain extender的含量對熱裂解溫度沒有顯著影響(差值皆在10 oC內),但改變Chain extender種類卻會大幅度改變其熱裂解溫度 [5% and 10% weight loss Temperature Glycerol(263~271oC)>DMPA(250~268oC)>Ethylene glycol(243~255oC)]。
A series of PDMS based Poly (urea-urethane) (PUU) with various polar functional groups on their side chain have been prepared by using prepolymer process. FT-IR was used to characterize the structure of the PUU. Surface polarity properties of the PUU films have been studied by the surface contact angle with water. The hydrophilic and hydrophobic characters of PUU films have been investigated. It was found that the PUU film material possesses different surface properties on the aluminum contacting face and on the air contacting face. Results show that the differences of contact angles between two sides of the PUU film are very significant. The contact angles of the aluminum-contacting side decreased with the increasing of the hard segment content in the PUU film. However, the contact angles of air-contacting side keep almost constant. X-ray Photoelectron spectra (XPS) or Electronic Scanning chemical Analysis (ESCA) provides surface chemical information. It was found that silicon contents on the air contacting surface and aluminum contacting surface are different. Results indicate that the silicone/nitrogen ratio on the aluminum-contacting surface is higher than that on the air-contacting surface, and the ratio decreases as the hard segment content increased. Scanning Electron Microscopy (SEM) microphotographs are utilitized to study the surface morphology. Different types of accumulation of PUU between the air (i.e. soft segment) and aluminum (i.e. hard segment)-contacting surface of PUU with different chain extenders were observed. Atomic Force Microscopy (AFM) topographies are utilitized to study the surface roughness. The difference of roughness among the various chain extender of PUU on the aluminum-contacting surface can be studied by the average roughness (Ra). It was be found that the Ra value of the air-contacting surface is larger than that of the aluminum- contacting surface. Surface electrical resistance properties of the PUU films have been studied by measuring the surface electrical resistance at different relative humidities. Results show that when the sample was in dry condition, the surface electrical resistance is in the range of 1014 Ω. However, when the sample was conditioned at 70%, 80% and 100% R.H., the surface resistance decreases to 108 Ω. This electrical resistance value could be applied to antistatic and ESD materials for military applications at some middle or high relative humidity. The mechanical properties of the PUU films material depend on the hard/soft segment ratio in PUU film. The tensile strength of PUU film is ranging from 0.2 Mpa to 8 Mpa; and elongation is from 20% to 900%; tensile modulus is from 2 Mpa to 130 Mpa. The reason that causes this phenomenon is due to the different hard segment content. The more the hard segment content, the lower the tensile strength and tensile modulus. In addition, the more the hard segment content, the higher the elongation. It was also found that the thermal decomposition temperatures of the PUU films are ranging from 270oC to 290oC. The effect of chain extender content on thermal decomposition temperature (the differences are all within 10oC) is insignificant. However, the types of chain extender affect the thermal decomposition temperature significantly. Since different chain extenders will form the different types of structure of PUU.
關鍵字: 聚胺基甲酸酯
矽氧烷
Urethane
Siloxane
Silicon distribution
surface electrical resistance
XPS
contact angle
SEM
出版年: 2001
描述: 碩士
國立清華大學
化學工程學系
NH900063024
URI: http://ir.lib.nthu.edu.tw/handle/987654321/33057
Appears in Collections:博碩士論文 - CHE Theses

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