Polystyrene nanofibers for nonwoven porous building insulation materials

Abstract

The building industry makes a great effort to reduce energy consumption. The use of nanotechnology is one of the approaches to surpassing the properties of conventional insulation materials. In this work, an industrial cost‐effective method to manufacture highly porous materials with excellent thermal insulation properties is described. The materials are prepared from polystyrene recovered from the building sector and electrospun as nanofiber‐based sheets. Varying electrospinning parameters allow controlling the morphology of the produced materials. The materials are obtained with differences in interfiber and inner‐fiber porosity and morphology. The thermal conductivity of the freestanding and compressed materials is evaluated. Those differences affect the insulation performance: the materials with higher interfiber porosity show better thermal insulation in the freestanding state. An increase of the inner‐fiber porosity leads to better insulation in the compressed samples. Insertion of carbon nanomaterials reduces the effects of the infrared Radiation. Nanofiber‐based insulation materials from the recycled expanded polystyrene (EPS) show thermal conductivity values of 20 to 25 mW/mK (ie, 20% to 30% below the thermal conductivity of the commercial EPS). The effect of integrating polystyrene nanofiber sheets into conventional wall‐building materials is also investigated in terms of thermal insulation. The nanofiber insulation sheets are sandwiched between two pieces of the building materials resulting in a drastic increase of the insulation effect. The materials have a great potential in using, for example, as thermal insulation for the restoration of historic buildings in the narrow central parts of the old towns.

Sound absorption and thermal insulation properties of composite thermoplastic polyurethane/polystyrene (TPU/PS) nanofiber web and TPU nanofiber web and PS-extracted TPU/PS microfiber web

“…The reason behind this drop of thermal conductivity might be because of more thermal resistant structure of PS polymer and higher pore volume, surface area, and lower density of TPU/PS-BSE. 29–32…”

“…The reason behind this drop of thermal conductivity might be because of more thermal resistant structure of PS polymer and higher pore volume, surface area, and lower density of TPU/PS-BSE. [29][30][31][32] On the other hand, 100% TPU reference nanofiber web and microfiber web after Soxhlet extraction (containing approximately 98% TPU and 2% PS) have similar thermal conductivity coefficients (0.09 and 0.094 W/mK with 10 À3 standard deviation, respectively). According to two tailed t-test at 0.05 significance level, the differences between thermal conductivity coefficient of TPU and TPU/PS-ASE are not significant.…”

Circulatory Management of Polymer Waste: Recycling into Fine Fibers and Their Applications

“…The purification of water from harmful organic compounds like bacteria, viruses, or even textile dyes has become a serious concern. A composite based on TiO 2 /styrofoam membranes prepared using electrospinning was developed by Rajak et al [ 122 ] to prevent a water hygiene crisis. Styrofoam from waste was used for the study, and TiO 2 as semiconductor catalyst material used in the environmentally friendly photocatalysis process was incorporated into the fine styrofoam fibers.…”

Improvement of insulation properties of glass fiber fabric/epoxy composites modified by polymeric and inorganic fillers

“…In the recent years, studies on nanofibers have been increasing and studies reported on nanofiber web reinforced glass/epoxy composites have mainly been focused on improvement of their mechanical properties. [26][27][28][29][30][31][32][33][34] However, many novel and light weight acoustical and thermal insulating materials have been introduced in recent years and nanofiber-based materials are promising materials for insulation application and other application areas such as energy storage and energy generators. [32,[35][36][37][38][39][40] Na et al [35] studied on the effect of layers of nanofiber webs on regular fiber knitted fabric on sound absorption.…”

“…Gibson et al [37] evaluated the thermal insulation of the electrospun polyacrylonitryl (PAN) nanofibers and found that with the use of PAN nanofibers, thermal insulation was greatly increased with the simultaneous decrease of the weight and size of protective clothing. With use of polystyrene (PS), Datsyuk et al [31] reported that nanofiber-based insulation materials from the recycled expanded polystyrene (EPS) had thermal conductivity values of 0.02-0.025 W/mK (i.e., 20%-30% below the thermal conductivity of the commercial EPS). Yoon et al [32] used PS with PA6 to obtain electrospun webs with the high-thermal resistance and reasonable mechanical strength.…”