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 °C. According to TG analysis, the weight loss of the SiAG/NNW is 5% at 464 °C, which is much higher than individual NNW (327 °C) or SiAG (456 °C). Moreover, the carbon residue rate of the nonwoven was raised from 54.3% to 73.7% at 800 °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.