聚苯乙烯/奈米石墨複合材料及泡材機械性質及泡孔型態之探討

Mechanical Properties and Morphology of Polystyrene/Graphene Nanocomposite Foam

黃建銘(Jian-Ming Huang)

指導教授 ： 葉樹開

國立臺北科技大學/工程學院/化學工程研究所/碩士(2014年)

https://doi.org/10.6841/NTUT.2014.00733

摘要

本實驗以PS為基材，添加不同的奈米填料製備PS/奈米複合材料，可分兩部分進行探討，第一部分為固態材料，第二部分為發泡材料，並進行泡孔型態、機械性質分析。
實驗發現，固態材料部分：PS添加四種不同奈米填料包括:直徑25 μm之脫層奈米層狀石墨(H25)、熱還原石墨烯 (TRG)、奈米碳纖維 (CNF)、奈米碳管 (CNT)，其中以溶液混合法提升效果最好，添加0.1 wt%的CNT、CNF，Young’s modulus分別從1844 MPa上升至2157 MPa、2824 MPa，相較於純PS提升了16.97%、13.74%，而由先前的實驗發現，僅添加0.1 wt%的TRG，Young’s modulus即可迅速的提升26.64% [1]，顯示TRG表現的效果較明顯，並以TEM觀察確認其分散型態。
而發泡材料部分：以顆粒批次發泡實驗發現，在低壓下(1100 psi)，添加0.5 wt%的TRG效果為最佳，泡孔密度可從3.55×107 cells/cm3上升至7.55×109 cells/cm3，可提升212倍，而泡孔大小可從83.98 μm下降至10.69 μm，縮小了87%，而提高TRG添加量到1 wt%時，效果反而不好，泡孔密度、泡孔大小分別僅只有1.16×109 cells/cm3、18.71 μm [2]，效果沒有添加0.5 wt% TRG來得好。而在2000 psi壓力下的發泡結果顯示，依然是0.5 wt%的TRG表現最優異，但是泡孔尺寸以及泡孔密度沒有與0.1 wt%、1 wt%TRG有太大差異。
而啞鈴型試片發泡批次發泡實驗發現，把純PS試片放在緊密的模具，並在不同溫度下進行發泡，使泡體只能在一維方向生長，並從SEM圖發現，120˚C這組，泡孔大小較均勻，斷裂伸長率較高，且有較高的強度/密度比(Young’s modulus / relative density)。並發現僅添加0.1 wt%TRG，可使發泡材的泡孔尺寸變小，並且泡孔密度更高。

關鍵字

石墨烯 ； 奈米碳管 ； 奈米碳纖維 ； 奈米層狀石墨 ； 聚苯乙烯 ； 超臨界二氧化碳 ； 發泡 ； 機械性質

並列摘要

In this research, polystyrene / carbon nanocomposites were prepared by adding different types of nanoparticles. The mechanical properties of solid nanocomposites and their foam were studied. The different carbon nanoparticles used in this study were graphene, nanographite, carbon nanofiber and carbon nanotubes.
Among the four different nanoparticles graphene showed the best mechanical properties. By adding 0.1 wt% of CNT、CNF would increase Young’s modulus from 1844 MPa to 2157 MPa and 2824 MPa respectively. By adding only 0.1 wt% of grapheme would result in 26.64% increase in modulus.
The polymer-graphene nanocomposite foam was prepared using a batch foaming technique. The cell morphology changed significantly in the presence of graphene. The batch foaming results showed that adding 0.5 wt% of TRG (thermally reduced graphene) would increase the cell density from 3.55×107 cells/cm3 to 7.55×109 cells/cm3, and the cell size dropped from 83.98 μm to 10.69 μm. Adding 1 wt% of TRG , the effect is rather bad, cell density and cell size only 1.16 × 109 cells/cm3、18.71 μm respectively.
In the second part of foaming study, dumbbell shape samples were prepared by one dimensional foaming. The pure polystyrene samples were confined in a mold and only allowed to grow in one dimension. The samples were foamed at different temperatures (from 80˚C to 120˚C) to control the density and cell morphology of the sample. The experiment results showed that samples foamed at 120˚C possess uniform cell size and they showed a higher elongation at break than samples foamed at other temperature. Only adding 0.1 wt% TRG, makes the foamed material cell size becomes smaller, and the higher cell density foam.

並列關鍵字

graphene ； polystyrene ； supercritical CO2 ； foam ； mechanical properties

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