Thermal degradation and fire behaviour of thermal insulation materials based on food crop by-products

Abstract

Natural thermal insulation materials developed from renewable crop by-products and natural binders are analysed in terms of their thermal degradation and fire behaviour. A pyrolysis combustion flow calorimetre (PCFC) is used to characterise some kinds of crop by-products, including rice husk, corn pith and barley straw. This technique is complemented with a TG analysis. Six thermal insulation materials, formulated with such crop by-products and two kind of natural binders, corn starch and sodium alginate, are developed and analysed. PCFC results show an improvement when sodium alginate is incorporated, especially in the corn pith composite. Fire reaction tests are also performed that yield results which are in qualitative agreement with the small-scale tests.

Improvement of fire reaction and mould growth resistance of a new bio-based thermal insulation material

“…The onset temperature T0 (defined here as the temperature at which HRR reaches 10 W/g) was almost 100ºC higher than non-treated boards as the initial shoulder was displaced to the right, the PHRR was reduced more than three times and the mass loss was lower. Alginate showed a significant improvement, in agreement with the results previously found [Palumbo 2015], although it was moderate compared with boric acid. The addition of ammonium polyphosphate resulted in a 25% reduction of the peak heat release and a displacement of the initial shoulder to the right.…”

“…In previous work it was found that corn pith-alginate composites presented a remarkable propensity to smouldering combustion [Palumbo 2015]. Although fire reaction tests yielded good results, even for non-treated specimens, as they showed a self-extinguishing behaviour, after flame extinction a slow smouldering process proceeded until the complete consumption of the specimens.…”

“…The use of alginate as a binder improved the properties of the crop by-product alone, especially in the case of corn pith, where both the total heat release HR and the peak of heat release rate PHRR were reduced by 30%. In addition to flaming combustion, that take place in gas phase between the generated volatile gases and oxygen, smouldering was also observed in corn pith based panels [Palumbo 2015]. Smouldering is a slow flameless form of combustion that is sustained by the exothermic surface reaction between solid fuel and oxygen.…”

“…In a previous paper [Palumbo 2015], the fire behaviour of experimental insulation materials based on food crop by-products (rice husk, barley straw and corn pith) and natural binders (sodium alginate and corn starch) was evaluated. Both, small-scale pyrolysis combustion flow calorimetry (PCFC) and fire reaction tests indicated that the fire properties of the six experimental natural insulation materials were very favourable when compared with other organic foamy materials commonly used in building insulation, such as polystyrene and polyurethane.…”

“…In this research, the performance of an innovative thermal insulation rigid board is evaluated. The board is based on corn pith agglutinated with sodium alginate [Palumbo 2015;Palumbo 2014]. Here, the corn pith is pre-treated with different substances i.e.…”