多尺度相改性碳泡沫复合材料的制备及性能

Preparation and properties of multiscale phase modified carbon foam composites

为了提升传统碳泡沫的性能,以聚苯乙烯微球和酚醛微球为模板,酚醛树脂为碳源,纳米SiO_(2)颗粒为增强相,制备了一种含微纳米多尺度相的碳泡沫复合材料。分别采用电子扫描显微镜、热失重测试仪、万能试验机等,研究碳泡沫前驱体及不同SiO_(2)含量下,碳泡沫复合材料的微观结构、热稳定性、力学性能及抗氧化性能。结果表明:纳米SiO_(2)颗粒的引入,使碳泡沫复合材料的压缩性能显著提高,这得益于SiO_(2)相对裂纹扩展的阻碍;SiO_(2)质量分数为5%的碳泡沫复合材料,压缩强度和比压缩强度均达到最大,分别为12.2 MPa和33.5 MPa·cm^(3)·g^(-1),较改性前分别提高76.8%和65.3%。该样品的耐热氧化性能最优,在650℃下氧化25 min,其质量损失由33%降低为20%,较改性前相比,耐高温抗氧化能力提高了39.4%。

Carbon foam composites containing multiscale phase,were prepared with polystyrene(PS)and phenolic microsphere as the template,SiO_(2)nanoparticles as reinforcement,and phenolic resin as the carbon source,for improving their properties.Sanning electron microscope(SEM)、thermogravimetric(TG)and universal test machine,were employed to investigate the precursor and the microstructure,thermal stability,mechanical and anti-oxidation properties of carbon foam composites with different SiO_(2)content,respectively.Results showed that the introduction of SiO_(2)nanoparticles improved the compression performance of carbon foam composites significantly,thanks to the obstruction of crack propagation by SiO_(2)phase.Carbon foam composites with 5%SiO_(2)(in mass fraction),showed the optimal compressive strength(12.2 MPa)and specific compressive strength(33.5 MPa·cm^(3)·g^(-1)),which increased by 76.8%and 65.3%,respectively,compared with the unmodified one.Such sample also presented the better thermal oxidative resistance,whose weight loss reduced from^(3)3%to 20%,during the isothermal oxidation at 650℃for 25 min.Its thermal oxidative resistance performance increased 39.4%,compared to that of the pure carbon foam.