Abstract

Freeze-dried wheat gluten foams were evaluated with respect to their thermal and fire-retardant properties, which are important for insulation applications. The thermal properties were assessed by differential scanning calorimetry, the laser flash method and a hot plate method. The unplasticised foam showed a similar specific heat capacity, a lower thermal diffusivity and a slightly higher thermal conductivity than conventional rigid polystyrene and polyurethane insulation foams. Interestingly, the thermal conductivity was similar to that of closed cell polyethylene and glass-wool insulation materials. Cone calorimetry showed that, compared to a polyurethane foam, both unplasticised and glycerol-plasticised foams had a significantly longer time to ignition, a lower effective heat of combustion and a higher char content. Overall, the unplasticised foam showed better fire-proof properties than the plasticized foam. The UL 94 test revealed that the unplasticised foam did not drip (form droplets of low viscous material) and, although the burning times varied, self-extinguished after flame removal. To conclude both the insulation and fire-retardant properties were very promising for the wheat gluten foam.

Keywords

wheat gluten; foam; glycerol; freeze-drying; thermal conductivity; combustion

Published in

ACS Applied Materials and Interfaces
2012, Volume: 4, number: 3, pages: 1629-1635
Publisher: AMER CHEMICAL SOC

SLU Authors

• Johansson, Eva

  • Department of Biosystems and Technology, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Other Materials Engineering


Publication identifier

DOI: https://doi.org/10.1021/am2017877

Permanent link to this page (URI)

https://res.slu.se/id/publ/45660