Comparative analysis of sound and thermal insulation properties of porous and non-porous polystyrene submicron fiber membranes

Interior and surface porous materials have widespread use in a wide variety of applications, especially for thermal and sound insulation due to their porous structure. Both sound and thermal insulation have great importance in a wide range of technical textile application areas including clothing and transportation such as train, car, aerospace and so on. In this study, for the first time, porous and non-porous polystyrene submicron fibers membranes have been compared for both sound absorption insulation and thermal insulation properties at the same time. Porous polystyrene electrospun fibers were produced at two different ratios of DMF:THF (4:1 and 7:3 ratio of DMF:THF) under conrolled humidity environment (60% RH). The results show that higher sound absorption insulation (SAC values) were obtained for non-porous fiber membrane (PS-ref) produced under ambient condition (30% RH) than porous fiber membrane (PS/7:3/RH and PS/4:1/RH) produced under controlled humidity condition (60% RH) by use of DMF:THF in 7:3 ratio and 4:1 ratio. Similar tendency was observed for thermal conductivity coefficient. Thus, all these results show that thinner fiber leading higher surface area has more dominant effect on both thermal insulation and sound absorption insulation than the formation of porous structures on the surface or internal structure of the fiber.