论文部分内容阅读
为提高酚醛泡沫材料的耐高温性能和高温裂解前后的力学性能,通过物理共混法在发泡酚醛树脂中添加二硼化钛(TiB_2)无机填料制备了酚醛/TiB_2泡沫复合材料。研究了泡沫复合材料的固化过程和在1 000℃下裂解前后的微观结构,以及不同的TiB_2颗粒含量对泡沫复合材料的热物理性能、裂解前后力学性能的影响。结果表明,添加的TiB_2颗粒并不能被引入到酚醛树脂的分子链中,但是能够与酚醛树脂裂解释放出的含氧气体发生氧化还原反应,将裂解气体中的C和O元素吸收并转化为无定形碳和TiO_2等固相产物,从而提高了酚醛泡沫的残炭率和裂解后的力学性能。随着TiB_2含量的增加,泡沫复合材料的残炭率以及裂解前后的表观密度、比压缩强度和比弯曲强度均呈上升趋势,其中裂解后的强度上升更为明显。当TiB_2用量为30份时,酚醛泡沫复合材料在1 000℃下裂解产物的残炭率、比压缩强度和比弯曲强度分别比纯酚醛泡沫材料提高了39.2%,76.5%和43.9%。
In order to improve the high temperature resistance of phenolic foam and the mechanical properties before and after pyrolysis, phenolic / TiB_2 foam composites were prepared by adding inorganic filler of titanium diboride (TiB 2) to the foamed phenolic resin through physical blending method. The curing process of the foam composite and the microstructure before and after pyrolysis at 1 000 ℃ were studied. The effects of different TiB 2 content on the thermophysical properties and the mechanical properties before and after pyrolysis were investigated. The results show that the added TiB 2 particles can not be introduced into the molecular chain of the phenolic resin, but can react with the oxygen-containing gas released by the cracking of the phenolic resin to undergo redox reaction to absorb and convert the C and O elements in the pyrolysis gas into Carbon nanotubes, carbon nanotubes, carbon nanotubes, carbon nanotubes, carbon nanotubes and carbon nanotubes. With the increase of TiB 2 content, the residual char yield and the apparent density, specific compressive strength and flexural strength before and after pyrolysis increased with the increase of TiB 2 content, and the strength increased more obviously after pyrolysis. When the dosage of TiB_2 is 30, the residual char yield, specific compressive strength and flexural strength of the cracked product of the phenolic foam composites increase by 39.2%, 76.5% and 43.9%, respectively, compared with the pure phenolic foam at 1 000 ℃.