Preparation, mechanical, thermal and ablative properties of lightweight needled carbon fibre felt/phenolic resin aerogel composite with a bird's nest structure
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- 作者：Haiming Cheng ; hmingcheng@yeah.net ; Huafei Xue ; Changqing Hong ; hongcq@hit.edu.cn ; Xinghong Zhang
- 关键词：Fabrics ; Aerogel ; Porosity ; Mechanical properties ; Thermal properties
- 刊名：Composites Science and Technology
- 出版年：2017
- 出版时间：1 March 2017
- 年：2017
- 卷：140
- 期：Complete
- 页码：63-72
- 全文大小：3445 K
- 卷排序：140
文摘
A novel lightweight needled carbon fibre felt/phenolic resin (NCF-PR) aerogel composite was fabricated through vacuum impregnation using NCF as matrix and PR aerogels as filler. The PR aerogels was synthesized through polymerization-induced phase separation (PIPS), accompanied by solvent exchange and ambient pressure drying, from a resin mixture of PR with ethylene glycol (EG) as the porogen and hexamethylenetetramine (HMTA) as the catalyst. A homogeneous microstructure without macroscopic cracking and agglomeration was achieved in the composite, and the macropores between the fibres in the NCF were fully and uniformly filled by PR aerogels with high porosity and with large amounts of mesopores. The resulting NCF-PR aerogel composites exhibit low densities between 0.270 and 0.370 g/cm3, relatively high compressive strength, ranging from 0.83 to 11.02 MPa, and low thermal conductivities of 0.093–0.230 W/(mK) at room temperature. The thermal ablative properties of the aerogel composite were studied under arc jet conditions at a heat flux of 1.5 MW/m2 for 33 s. The ablation results demonstrate that the NCF-PR aerogel composite could deliver good thermal ablative and insulative properties (linear ablation rates as low as 0.029 mm/s and internal temperature peaks below 90 °C at 38 mm in-depth position as the surface temperature exceeded 2000 °C). Therefore, this lightweight carbon/phenolic composite is an excellent heat-insulation and thermal-protection material with applications in the fields of energy-saving and aerospace.