高分子膜之製造與特性研究

Fabrication and Characterization of Polymer Film

蘇 滔(Suprapto)

指導教授 ： 丁鏞

中原大學/工學院/機械工程研究所/博士(2020年)

https://doi.org/10.6840/cycu202000903

摘要

摘要

以聚偏二氟乙烯(polyvinylidene fluoride PVDF)為基礎之壓電材料具有強大的壓電響應、柔韌性、和輕巧性，已被廣泛用於各種機電應用中。而陶瓷-聚合物複合材料具有硬度、彈性、柔韌性、低密度，和良好的壓電響應、以及高擊穿強度等優點，成為具有潛力的新型結構和功能材料，相當適合設計機電元件，也因此引起許多研究題材。本論文主要有三個部分研究，包括單軸和雙軸拉伸、使用離子液體(Ionic Liquid, IL)和溶液澆鑄法、使用鋯鈦酸鉛(lead zirconate titanate, PZT)作為填充劑結合於溶液澆鑄法之聚合物基體中，然後進行退火處理。如何提高基於聚合物PVDF的β相和壓電常數是本研究之重點。單軸和雙軸拉伸可以幫助對齊結構的偶極矩，從而增強壓電性能。據此，針對機械拉伸的溫度、拉伸比、和拉伸速度因素所產生的影響進行探討。發現在80℃的溫度下單軸拉伸比R＝6以及雙軸拉伸比R＝4×4會獲得較大的β相成分和壓電性。另製備一種簡單的方法可直接從熔融過程中獲得高β相PVDF。通過溶液澆鑄法製備PVDF和作為填充劑的離子液體，並適當地進行隨後的退火處理。將PVDF薄膜樣品浸入熱水中，以在不同溫度(25°C至70°C)下進行退火處理。實驗中發現在高溫下退火，不僅可以增加更多的離子液體滲入聚合物基體內之無定形區域，獲得更多的相變產生，而且可加速去除離子液體。最終提出之方法是以溶液澆鑄法產出PZT-PVDF複合材料，然後進行熱壓法(Hot Pressing, HP)並實施退火處理。將填料PZT摻入聚合物基體是產生高壓電性的一種簡單方法。據此，藉由檢測複合膜的微觀結構和機電性能，亦研究PZT含量的定性和定量以及熱壓壓力的影響。由實驗結果可知，提高熱壓壓力以及PZT的含量，可獲得較大的輸出電壓和較高的靈敏度。

關鍵字：壓電材料、聚偏二氟乙烯、陶瓷-聚合物複合材料、拉伸、溶液澆鑄、熱壓。

關鍵字

壓電材料 ； 聚偏二氟乙烯 ； 陶瓷-聚合物複合材料 ； 拉伸 ； 溶液澆鑄 ； 熱壓.

並列摘要

Abstract

Piezoelectric materials based on polyvinylidene fluoride (PVDF) have been widely used in various electromechanical applications due to strong piezoelectric response, flexibility, and lightweight. Ceramic-polymer composites form a new class of structures, and functional material of great potential in having combined hardness and elasticity, flexibility, low density, good piezoelectric response, and high breakdown strength of polymers makes them suitable candidates for electromechanical devices and have attracted tremendous research interest. This dissertation mainly consists of three sections: uniaxial and biaxial stretching, solution casting with Ionic Liquid (IL), and lead zirconate titanate (PZT) as filler into polymer matrix then followed by annealing treatment. How to obtain and enhance β-phase and piezoelectric constant based on polymers PVDF is the focus in this study. Uniaxially and biaxially stretching can help align the dipole moments of structure to enhance the piezoelectric properties. Additionally, the influence of subsequent mechanical stretching, e.g., temperature, stretch ratio, and speed rate, also investigated. It was found that a stretching ratio of R=6 (uniaxial) and R=4x4 (biaxial) at a temperature of 80°C would have a maximum fraction of β-phase and piezoelectric properties. A simple method was prepared to obtain high β-phase PVDF directly from the melting process. PVDF and IL as filler were prepared by a solution casting method with appropriate associated with the subsequent annealing treatment. PVDF film sample is immersed in hot water for annealing treatment at different temperatures (25°C to 70°C). As found, annealing in high temperature, especially, not only can increase more IL inserted into the amorphous region of the polymer matrix to make more phase transformation but also accelerate IL removal. The final proposed method makes the PZT-PVDF composites by solution casting and then by Hot Pressing (HP) for annealing treatment. Incorporating fillers PZT into the polymer matrix is an easy way to produce high piezoelectric constant. The influence of the PZT content and the pressure in HP treatment on the microstructure and electromechanical properties of the composite films are the focus of both qualitative and quantitative studies. It concludes that increasing the content of PZT and pressure in HP, the piezoelectric properties were improved, and large output voltage and high sensitivity were obtained.
Keywords: piezoelectric material, PVDF, PZT-PVDF composites, stretching, solution casting, hot pressing.

並列關鍵字

piezoelectric material ； PVDF ； PZT-PVDF composites ； stretching ； solution casting ； hot pressing.

參考文獻

References

1. Kawai, H., The piezoelectricity of poly (vinylidene fluoride). Journal of Applied Physics 8.7, 1969. 8(7): p. 975.

2. Sencadas, V., Moreira, M. V., Lanceros-Méndez, S., Pouzada, A. S., & Gregório Filho, R, α - to - β Transformation on PVDF Films Obtained by Uniaxial Stretch.pdf. In Materials science forum, 2006. 514: p. 872-876.

3. Kulek, J., B. Hilczer, and A. Szlaferek, Effect of the poling temperature on the dielectric properties of oriented PVDF film. Ferroelectrics, 1988. 81(1): p. 365-368.

4. Scheinbeim, J., et al., High‐pressure crystallization of poly (vinylidene fluoride). Journal of Applied Physics, 1979. 50(6): p. 4399-4405.