Preparation of needled nonwoven enhanced silica aerogel for thermal insulation

Benefiting from the advantages of light weight, porosity, high specific surface area and ultra-low thermal conductivity, silica aerogel (SiAG) has been regarded as ideal thermal insulation material. However, the low strength and fragility limited its application. In this paper, the needled nonwoven (NNW) composed of polyphenylene sulfide fibers and pre-oxidized fibers was applied as substrate for incorporating with silica aerogel (SiAG/NNW) to coordinate the heat preservation. Various characterizations were carried out to discuss thermal insulation property. The results showed that SiAG/NNW can last for 4min under butane flame with a certain impact force at about 1300 degrees C. According to TG analysis, the weight loss of the SiAG/NNW is 5% at 464 degrees C, which is much higher than individual NNW (327 degrees C) or SiAG (456 degrees C). Moreover, the carbon residue rate of the nonwoven was raised from 54.3% to 73.7% at 800 degrees C after SiAG incorporation. The fiber morphology can still be observed at the flame perforation of SiAG/NNW with low carbonization degree and no obvious decomposition to SiAG. Significantly, thermal protective performance (TPP) values of the SiAG/NNW can reach 1272 kW s/m2 which is twice of the NNW. In conclusion, the prepared SiAG/NNW showed high temperature resistance and excellent thermal insulation, the results also provides a technical scheme for future development of thermal insulation materials at high temperature.

Automated summary

In this study, a needled nonwoven (NNW) composed of polyphenylene sulfide fibers and pre-oxidized fibers was used as a substrate to incorporate silica aerogel (SiAG/NNW) for thermal insulation. The SiAG/NNW showed high temperature resistance and excellent thermal insulation, with the ability to withstand butane flame for 4 minutes at about 1300 degrees C. The SiAG/NNW also exhibited higher weight loss temperature and improved carbon residue rate compared to individual NNW or SiAG.