溫度效應對奈米碳管/玻璃纖維積層板之機械性質與黏彈特性研究

Thermal Effects on Mechanical and Viscoelastic Properties of CNT/GFRP Laminates

林亦杰(Yi-Chieh Lin)

指導教授 ： 葉銘泉

國立清華大學/工學院/動力機械工程學系/碩士(2008年)

https://doi.org/10.6843/NTHU.2008.00208

摘要

奈米碳管擁有高潛力用來增加高分子複合材料機械和物理質性質。因此本研究製程利用超音波分散奈米碳管及手積層的方式製備奈米高分子預浸材。本研究旨在添加不同含量奈米碳管對玻璃纖維積層板複合材料之彎曲強度、層間剪切強度影響，結果指出添加0.75phr奈米碳管，積層板層間剪切強度、彎曲強度最佳，分別增加15.7%和9.2%。
透過不同環境溫度進行測試，最高達200°C，瞭解添加奈米碳管對玻璃纖維積層板溫度效應下機械性質影響。結果顯示在各不同環境溫度下積層板層間剪切強度、彎曲強度、彎曲模數和疲勞性質因添加奈米碳管而有所增加。利用動態機械分析(DMA)計算儲存模數，結果顯示溫度效應對靜態之彎曲強度、彎曲模數和積層板層間剪切強度測試數據與動態機械性質皆為溫度相依且趨勢幾乎相同，因溫度效應讓基材軟化加上纖維介面強度變弱是使強度與模數下降重要因素。以SEM觀察破壞面，藉此了解複合材料微觀破壞情況及其內部奈米碳管的分散排列情形。
因玻璃纖維積層板的基材為高分子材料，機械性質會因溫度和時間關係而大幅影響，此重要特性可視為黏彈材料。透過時間-溫度疊合原理(TTSP) 將DMA測試結果在選擇參考溫度下透過水平平移因子將不同溫度的模數相對頻率曲線組成儲存模數、損失模數相對頻率的主導曲線(Master curve)。時間-溫度疊合原理可將短期(Short term) 儲存模數、損失模數、tanδ和鬆弛模數測試用來預測長期(Long term)頻率、時間範圍測試。

關鍵字

溫度效應 ； 奈米碳管 ； 積層板 ； 機械性質 ； 黏彈特性

並列摘要

Carbon nanotubes (CNTs) provide a high potential for the modification of glass-fiber reinforced polymer (GFRP) composite laminates. This paper reports CNTs/GFRP composite laminates were fabricated by using ultrasonication and the hand layup method. This study was aimed at investigating the interlaminar shear strength (ILSS) and flexural strength of composites consisting of adding several different proportions of CNTs. When CNTs content is 0.75 phr (per hundred resin), the mechanical properties are the best. The ILSS and flexural strength were significantly improved by 15.7% and 9.2%, respectively.
The effects of CNTs addition on the mechanical performances were evaluated with respect to retention of high-temperature properties up to 200 °C. It was found that ILSS, flexural strength , bending modulus and fatigue properties were significantly enhanced by CNTs at different evaluated temperatures. Fiber-matrix interfacial strength significant weakening and matrix softening was a major factor affecting the strength and modulus reduction observed at high temperature. The storage modulus, measured by dynamic mechanical analysis (DMA), showed temperature dependence nearly identical to the ILSS, flexural strength and bending modulus for GFRP and CNTs/GFRP composite laminates. The experimental results were examined to understand the fracture surface observed by scanning electron microscope (SEM).
In addition, because the matrix is polymer-based and its mechanical properties are influenced by both temperature and time, it is important to consider its viscoelastic behavior. This was accomplished by conducting the time-temperature superposition principle (TTSP) experiments using DMA. From the TTSP results, master curves were constructed for the storage (E’) and the loss moduli (E”) as a function of frequency at pre-selected reference temperature. The long-term storage modulus, loss modulus, tanδ and relaxation modulus of GFRP was predicted based on TTSP.

並列關鍵字

thermal effect ； CNT ； laminates ； mechanical properties ； viscoelastic behaviors

參考文獻

1. S. Iijima “Helical microtubules of graphitic carbon,” Nature, Vol.354, pp.56–58, (1991).

2. M. Cochet, W. K. Maser, A. M. Benito, M. A. Callejas, M. T. Martinez and J. M. Benoit, “Synthesis of a new polyaniline/nanotube composite: “in-situ” polymerization and charge transfer through siteselective interaction,” Chem. Comm, Vol.16, pp.1450–1451, (2001).

3. S. Kumar, H. Doshi, M. Srinivasarao, J. O. Park and D. A. Schiraldi, “Fibers from polypropylene/nano carbon fiber composites,” Polymer, Vol.43, pp.1701–1703, (2002).

4. D. Qian, E. C. Dickey, R. Andrews and T. Rantell, “Load transfer and deformation mechanisms in carbon nanotube-polystyrene composites,” Applied Physics Letters, Vol.76(20), pp.2868–2870, (2000).

5. A. Peigney, E. Flahaut, C. H. Laurent, F. Chastel and A. Rousset, “Aligned carbon nanotubes in ceramic-matrix nanocomposites prepared by high-temperature extrusion,” Chemical Physics Letters, Vol.352, pp.20–25, (2002).