Preparation and characterization of granular silica aerogel/polyisocyanurate rigid foam composites

Abstract

Energy conservation is an increasingly important issue in building and construction. Consequently, thermal insulation of building materials, particularly insulation systems for external walls, has attracted increasing attention in recent years. A novel organic/inorganic composite rigid foam (polyisocyanurate and granular silica aerogel) with excellent flame retardant and thermal insulation properties has been synthesized. The effects of granular silica aerogel and polymer polyols on the performance of composites were characterized using scanning electron microscopy (SEM), oxygen index (OI), thermal conductivity and mechanical evaluation. The OI value of the composite foam prepared with polyethylene glycol 600 increased from 29.4% (0wt.% aerogel) to 34.6% (8wt.% aerogel), indicating improved thermal stability, and thermal conductivity was reduced by 32.7% (0.0233W/(mK) at 8wt.% aerogel) compared with polyisocyanurate (PIR) rigid foam (0.0346W/(mK)). Waste residue (a by-product from the preparation of 1,4-butanediol) was successfully used to partially replace the polyol source in order to effectively reduce costs.