本文關(guān)鍵詞： wetting ridge 聚苯乙烯 薄膜 黏度 平臺模量 黏流溫度　出處：《浙江理工大學(xué)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：聚合物薄膜黏彈性是其分子運(yùn)動的宏觀體現(xiàn),對于聚合物納米材料的性能調(diào)控及加工成型具有重要意義。由于納米受限效應(yīng),聚合物薄膜具有與本體不同的黏彈響應(yīng)行為。聚合物薄膜黏彈性的測量一直是學(xué)術(shù)界研究的焦點(diǎn)和難題之一。因此,開發(fā)聚合物薄膜黏彈性研究的新方法對于探究聚合物薄膜分子運(yùn)動的微觀機(jī)制以及完善受限高分子運(yùn)動理論具有重要意義。本論文研究了聚苯乙烯(PS)薄膜的黏彈性與其表面wetting ridge的形成及發(fā)展過程的關(guān)系。所得結(jié)論如下:(1)通過研究wetting ridge的發(fā)展動力學(xué)開發(fā)了一種原位測量聚合物薄膜黏度的新方法。以550nm的聚苯乙烯(PS)膜為研究對象,研究了不同溫度下在離子液體表面張力作用下產(chǎn)生的PS膜表面wetting ridge的形成及發(fā)展過程。發(fā)現(xiàn)wetting ridge高度隨液滴作用時間逐漸增大,時間足夠長時,wetting ridge高度隨時間呈線性增長。研究了在不同溫度下不同分子量PS膜表面wetting ridge高度與時間線性增長部分的斜率(k),并關(guān)聯(lián)了線性斜率k與相對應(yīng)的溫度及分子量下PS的黏度(η)的關(guān)系,發(fā)現(xiàn)二者滿足公式:η=0.37γsinθ/k。改變離子液體的表面張力,發(fā)現(xiàn)兩種表面張力不同的離子液體所得的1/k與η均滿足這一公式。這一結(jié)果表明通過監(jiān)測wetting ridge形成及發(fā)展過程是一種研究聚合物膜黏度的有效方法。(2)利用上述方法研究了不同基底上PS薄膜黏度的厚度依賴性。結(jié)果發(fā)現(xiàn),Si O2上PS薄膜的黏度隨厚度的降低而降低,Si-H上PS薄膜黏度隨厚度降低而升高,這是PS與基底之間的界面效應(yīng)導(dǎo)致的,與文獻(xiàn)報(bào)道相符;薄膜黏度產(chǎn)生厚度依賴性的臨界厚度為10Rg,也與文獻(xiàn)報(bào)道相符。結(jié)果說明這一新的方法可以敏感的反映薄膜厚度及基底性質(zhì)對薄膜分子鏈整鏈運(yùn)動的影響,是一種探測聚合物薄膜及超薄膜黏度的有效方法。(3)通過不同溫度下wetting ridge的高度變化研究了聚苯乙烯(PS)膜力學(xué)性質(zhì)與溫度的關(guān)系,發(fā)展了研究聚合物膜平臺模量及黏流溫度的新方法。研究發(fā)現(xiàn),wetting ridge高度與溫度的關(guān)系曲線(h-T曲線)與聚合物的形變溫度曲線類似。Wetting ridge的h-T曲線中存在平臺區(qū)域,在這一區(qū)域內(nèi)wetting ridge的高度保持恒定,不受溫度、PS分子量的影響。利用Wetting ridge的平臺高度可以估算PS的平臺模量(~105.85Pa),其值與文獻(xiàn)報(bào)道的模量值基本相同。同時,wetting ridge的平臺區(qū)域結(jié)束的臨界溫度(T*)與PS的黏流溫度(Tf)滿足相同的分子量依賴性,并且滿足Tf=T*+10℃的定量關(guān)系。T*隨液滴作用時間增長而降低,二者關(guān)系滿足Arrhenius方程,得到與T*相關(guān)的活化能,其值與PS的黏流活化能一致。該結(jié)果進(jìn)一步證明T*與PS的黏流形變相關(guān),與Tf具有相似物理意義。
[Abstract]:The viscoelasticity of polymer film is the macroscopical embodiment of its molecular motion, which is of great significance to the performance control and processing of polymer nanomaterials. The viscoelastic response behavior of polymer film is different from that of bulk film. The measurement of viscoelasticity of polymer film has always been one of the focuses and problems in academic research. It is important to develop a new method to study the viscoelasticity of polymer films. In this paper, the viscoelastic properties of PS / PS films are studied in order to explore the micro mechanism of molecular motion and improve the theory of confined polymer motion. The relationship between the properties and the formation and development of wetting ridge on the surface. The conclusions are as follows: 1) A new method for in-situ measurement of viscosity of polymer films has been developed by studying the development kinetics of wetting ridge. The formation and development of wetting ridge on the surface of PS film under the action of surface tension of ionic liquid at different temperatures were studied. It was found that the height of wetting ridge increased with the time of droplet action. When the time is long enough, the height of wetting ridge increases linearly with time. The slope of wetting ridge height and time linear increasing part of PS film surface with different molecular weight at different temperature is studied, and the linear slope k is correlated with the corresponding temperature. And the relationship between the viscosity (畏) of PS at molecular weight, It is found that both of them satisfy the formula: 畏 0. 37 緯 sin 胃 / k. change the surface tension of ionic liquids, It is found that 1 / k and 畏 of two ionic liquids with different surface tension satisfy this formula. The results show that monitoring the formation and development of wetting ridge is an effective method to study the viscosity of polymer membranes. The thickness dependence of PS film viscosity on different substrates was studied. The results show that the viscosity of PS films on Si-H substrate decreases with the decrease of thickness, and increases with the decrease of thickness. This is caused by the interfacial effect between PS and substrate, which is consistent with the literature. The critical thickness of thickness dependence on film viscosity is 10Rg, which is consistent with the reported results. The results show that the new method can reflect the effects of film thickness and substrate properties on the whole chain motion of the film molecule. It is an effective method to detect the viscosity of polymer films and ultrathin films. The relationship between the mechanical properties and temperature of polystyrene (PS) films has been studied by the height variation of wetting ridge at different temperatures. A new method for studying the modulus and viscous flow temperature of polymer membrane platform is developed. It is found that there exists a platform region in the h-T curve of wetting ridge height and temperature) and the deformation temperature curve of polymer is similar to that of ridge. The height of wetting ridge remains constant in this area. The platform modulus of PS can be estimated by using the platform height of Wetting ridge, which is basically the same as that reported in the literature. At the same time, the critical temperature at the end of the platform region of the wetting ridge can be estimated by the critical temperature of the end of the platform region and the viscosity flow of PS can be estimated by using the platform height of Wetting ridge. The temperature Tf) satisfies the same molecular weight dependence. The quantitative relationship of TfN and T* 10 鈩，

本文編號：1547730