添加不同的奈米碳管對於碳纖維布強化 酚醛樹脂複合材料機械行為的影響

Effect of different CNT addition on the mechanical behavior of carbon fiber fabric/phenolic resin composites

楊凱婷(Kai-Ting Yang)

指導教授 ： 曾信雄

大同大學/工程學院/材料工程學系所/碩士(2010年)

摘要

本實驗用真空熱壓成型法製作添加奈米碳管的碳纖維布強化酚醛樹脂複合材料，並且利用三點彎曲法測量其機械性質。所添加的奈米碳管分別有3 nm、8 nm以及10-50nm三種不同的直徑。將經過機械測試後的試片以掃描式電子顯微鏡觀察其破斷面，並試著探討奈米碳管添加量對複合材料機械性質與破壞行為所造成的影響。實驗結果顯示，當奈米碳管的添加量增加，複材的彎曲強度會呈現先上升，再下降的趨勢，表示奈米碳管有一最佳的添加量。不同的奈米碳管會造成複材的彎曲強度呈現不同的提升效果，添入3nm奈米碳管在0.75wt%時有一最大彎曲強度761.9MPa，而添入8nm奈米碳管則在1.0wt%時有一最大彎曲強度778.9MPa，添加10-50nm奈米碳管則在0.5wt%有一最大彎曲強度771MPa。添加三種奈米碳管均無法增加複材之彎曲模數，而在添加1.0wt%10-50nm奈米碳管時，複材的彎曲模數發生下降，而在添加0.75wt% 3nm奈米碳管及8nm奈米碳管時，複材的彎曲模數發生下降。此外，短樑測試結果顯示原始短樑複材層間剪應力為34.2Mpa，在添加0.75wt%的3nmCNT時之複材層間剪應力為35.6MPa，且添加1.0wt%的8nmCNT之複材層間剪應力為35.5MPa，這表示添加CNT可增加基材與纖維束之間的界面強度，使得複材的層間裂痕減少，複材的層間剪應力提升。而添加1.0wt%的3nmCNT之複材層間剪應力下降為30.6MPa，表示添加過量的CNT，應力會集中在奈米碳管集中的區域而促使裂縫在此碳管集中處生成，造成複材的層間剪應力下降。

關鍵字

複合材料 ； 奈米碳管 ； 機械行為

並列摘要

Carbon fiber fabric/phenolic resin composites with the addition of carbon nanotubes (CNTs) were fabricated using vacuum bag hot pressing technique and the mechanical behavior was investigated using three-point bending test. CNTs of three different diameters (3nm、8nm and 10-50nm) were used. The fracture surfaces were observed using FE-SEM. Experimental results indicated that there is an optimum loading for the enhancement of the flexural strength. The optimum loading is 0.75wt% for the 3nm CNTs with a maximum strength of 760MPa. For the 8nm CNTs, the optimum loading is 1.0wt% with a maximum strength of 778MPa. For the 10-50nm CNTs, the optimum loading is 0.5wt% with a maximum strength of 771MPa. Contrary to the flexural strength, flexural modulus was not improved with the addition of CNTs. Decrease of flexural modulus was measured at the CNT loading of 1.0wt% for 10-50nm CNTs and at the loading of 0.75wt% for 3nm and 8nm CNTs. The results of short-beam test indicate that the interlaminar shear strength(ILSS) increased from 34.2MPa to 35.6MPa for the addition of 0.75wt% 3nm CNTs and from 34.2MPa to 35.5MPa for the addition of 1.0wt% 8nm CNTs. On the other hand, ILSS decreased to 30.6MPa for the addition of 1.0wt% 3nm CNTs, indicating that higher CNT loading will lower the ILSS and consequently, the flexural strength.

並列關鍵字

mechanical behavior ； composites ； CNT

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