微波膨胀石墨薄片/聚氨酯纳米复合材料的制备及表征

Preparation and Characterization of Microwave Expanded Graphite Flakes/Polyurethane Nanocomposites

通过改进的Hummers法制备了高氧化程度的氧化石墨(GO),再利用微波膨胀制备了石墨纳米薄片(wGO),并采用X射线能谱分析(EDS)、热重分析(TGA)、元素分析、红外分析对GO和wGO进行测试。结果表明,wGO中O含量较GO中明显减少,说明微波膨胀能还原GO,使其表面含氧基团减少;进一步采用X射线衍射(XRD)、原子力显微镜(AFM)对wGO的结构和形貌进行表征,表明微波法使GO层间距增大,剥离效果明显。利用溶液法原位聚合制备了wGO/聚氨酯弹性体(TPU)纳米复合材料,扫描电镜(SEM)观测显示,wGO在TPU基体中有良好的分散性;当wGO的质量分数为3%时,拉伸强度提高了116.1%;当其质量分数为2%时,导热性能和导电性能分别提高了72.4%和6个数量级。wGO/TPU纳米复合材料的微相分离程度更高,在室温下有更高的储存模量。

Highly oxidized graphite oxide （GO） was prepared by the modified Hummers method, and the nanographite flakes were prepared by microwave expansion （wGO）. The results of energy dispersive spectrometer （EDS）, TGA, elemental analysis and FT-IR show that O content of wGO is lower than that of GO, which indicates that GO was reduced by microwave expansion and the surface oxygen groups content reduce. The structure and morphology characteristics of wGO were characterized by XRD, AFM. The results show that the intercalating space of GO is increased by microwave expansion, the exfoliating effect is improved, wGO/polyurethane elastomer（TPU） composites were prepared via in-situ polymerization. The nanographite flakes uniformly disperse in the TPU matrix observed through scanning electron microscope （SEM）. Compared with the pristine TPU, the tensile strength is increased by 116.1% when the wGO mass fraction is 3 %, and the electrical conductivity and thermal coriductivity are increased by 72.4 % and 6 orders of magnitude respectively, when the wGO mass fraction is 2%. wGO/TPU nanocomposites have higher microphase separation degree and higher storage modulus at room temperature.