Impact of Leather on the Fire Resistance of Leather-Wood Fibreboard: FT-IR Spectroscopy and Pyrolysis-GC-MS Investigation

T Schnabel,M.-C Barbu,E Windeisen-Holzhauser,A Petutschnigg,G Tondi

doi:10.1155/2019/2473927

Abstract

Leather-wood fibreboards are innovative composite materials, which combine together the high mechanical properties of wood with the superior fire behaviour properties of leather. This study deals with the understanding of the combustion mechanism of the wet-white leather panel. During burning, an overlay coating-like surface is formed on top of a foamy structure that creates the heat transfer barrier. The FT-IR spectroscopy results of the leather show the rearrangement of the proteins and the formation of an increasing amount of acid groups when the exposure to hot gun at over 530°C was prolonged. These acid moieties can react with amino groups of other peptide chains, building a protective polymer network which hinders the oxygen to reach the core of the panel. Simultaneously, the gases produced during rearrangement cannot easily leave the material, producing a foamy structure which slows down the heat transfer to the core of the material. The Py-GC-MS analysis shows that the gases produced by the wet-white leather-type protein-based boards were amino-aromatic compounds like the diketopiperazine (DKP), which do not burn easily. The combination of the effects of (i) formation of the overlay coating-like surface, (ii) establishment of the foamy structure, and (iii) degassing of DKP explains the outstanding fire properties of leather and wood-leather fibreboards.

Highlights

Wood and leather are two of the oldest human civilizationused natural raw materials
An overlay coating-like surface is formed on top of a foamy structure that creates the heat transfer barrier. e FT-IR spectroscopy results of the leather show the rearrangement of the proteins and the formation of an increasing amount of acid groups when the exposure to hot gun at over 530°C was prolonged. ese acid moieties can react with amino groups of other peptide chains, building a protective polymer network which hinders the oxygen to reach the core of the panel
The gases produced during rearrangement cannot leave the material, producing a foamy structure which slows down the heat transfer to the core of the material. e Py-GC-MS analysis shows that the gases produced by the wetwhite leather-type protein-based boards were amino-aromatic compounds like the diketopiperazine (DKP), which do not burn . e combination of the effects of (i) formation of the overlay coating-like surface, (ii) establishment of the foamy structure, and (iii) degassing of DKP explains the outstanding fire properties of leather and wood-leather fibreboards

Summary

Introduction

Wood and leather are two of the oldest human civilizationused natural raw materials. Based on their organic compositions, their fire resistance is expected to be low. The combination of wood and leather changes the properties of both bioresources, resulting in improved composite material [4]. E tanning process can occur in three chemical ways: (i) through covalent bonds; (ii) through coordination bonds, and (iii) through secondary forces such as hydrogen bonds [6], and it generally affects the hydrothermal stabilization and the denaturation temperature of Advances in Materials Science and Engineering collagen [10]. Some publications presented leather has a naturally fire-resistant material [14,15,16], whereas the chemical process occurring was not elucidated

Methods

Results

Conclusion