Investigations of Accelerated Climate Aged Wood Substrates by Fourier Transform Infrared Material Characterization

Bjørn Petter Jelle,Petra Rüther,Per Jostein Hovde

doi:10.1155/2012/827471

Abstract

Fourier transform infrared (FTIR) material characterization by applying the attenuated total reflectance (ATR) experimental technique represents a powerful measurement tool. The ATR technique may be applied on both solid state materials, liquids and gases with none or only minor sample preparations, also including materials which are nontransparent to infrared radiation. This facilitation is made possible by pressing the sample directly onto various crystals, for example, diamond, with high refractive indices, in a special reflectance setup. Materials undergoing ageing processes by natural and accelerated climate exposure, decomposition and formation of chemical bonds and products, may be studied in an ATR-FTIR analysis. In this work, the ATR-FTIR technique is utilized to detect changes in selected wood building material substrates subjected to accelerated climate exposure conditions. Changes in specific FTIR absorbance peaks are designated to different wood deterioration processes. One aim is by ATR-FTIR analysis to be able to quantitatively determine the length of the wood ageing time before priming/treatment. Climate parameters like temperature (including freezing/thawing), relative air humidity, wind driven rain amount, solar and/or ultraviolet radiation, and exposure duration may be controlled in different climate ageing apparatuses. Both impregnated and raw wood samples have been employed in the experimental investigations.

Highlights

Wood deterioration of building materials due to natural climate ageing processes represents a problem
The attenuated total reflectance (ATR) technique may be applied on both solid state materials, liquids and gases with none or only minor sample preparations, including materials which are nontransparent to infrared radiation
For application of the ATR-Fourier transform infrared (FTIR) method on other building materials and processes, it is referred to the work by Jelle and Hovde [10] for FTIR investigations of wood rot decay and mould fungi growth on building materials and Jelle and Nilsen [11] for comparison of accelerated climate ageing methods of polymer building materials by FTIR

Summary

Introduction

Wood deterioration of building materials due to natural climate ageing processes represents a problem. For example, wood rot and mould fungus may in this context be viewed as (unwanted) results of the specific climate factors moisture and temperature for a certain exposure time with a sufficient supply of nourishment (e.g., wood). We are trying to utilize the attenuated total reflectance (ATR) Fourier transform infrared (FTIR) radiation technique in order to study wood decomposition in accelerated climate aged building material substrates. For application of the ATR-FTIR method on other building materials and processes, it is referred to the work by Jelle and Hovde [10] for FTIR investigations of wood rot decay and mould fungi growth on building materials and Jelle and Nilsen [11] for comparison of accelerated climate ageing methods of polymer building materials by FTIR. For a general review on accelerated climate ageing of building materials, components and structures in the laboratory, it is referred to the work of Jelle [12]

Experimental

Results and Discussion

Conclusions