Investigation of Novel Expandable Polystyrene/ Alumina Aerogel Composite Thermal Insulation Material

Abstract

Expandable polystyrene (EPS) foam is one of the most commonly used building thermal insulation materials due to its low thermal conductivity and low cost. However, its high flammability and the release of large amounts of toxic gases during combustion hinder its application. In this paper, using EPS foam and alumina aerogel (Al2O3) as insulation components, epoxy resin (EP) as a binder, and expandable graphite (EG) and ammonium polyphosphate (APP) as composite flame-retardant, a novel organic-inorganic composite thermal insulation material (EPS-AEA) was designed and fabricated. Experiment results showed that the adding Al2O3 to EPS could further reduce the thermal conductivity and improve its mechanical properties. And the addition of EG and APP composite flame-retardant could markedly enhance flame retardant performance. With the addition of 4.17% Al2O3 , 50% EG/APP ( 1/1 mass ratio ), EPS-AEA-1/1 composite showed superior fire resistance (reaching UL-94 V-0 rating and limiting oxygen index (LOI) of 40.6 %), high thermal insulation (thermal conductivity of 0.0487 W/(m·K)and applicable mechanical properties. In addition, EPS-AEA had excellent anti-hygroscopic property (moisture absorption/ desorption within 0.5 %), relatively small bulk density (about 160kg/m2), good thermal stability and fairly low toxic gas emissions during combustion, indicating its potential application in external building insulation.

Keywords: Expandable polystyrene, Alumina aerogel, Composite thermal insulation, Flame-retardant, Curbing toxic gas emissions