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The effects of thermal modification of wood have been well established, particularly in terms of reductions in mechanical performance. In recent years, there has been an increase in studies related to the Maillard reaction. More commonly associated with food chemistry, it involves the reaction of amines and reducing sugars during cooking procedures. This study has attempted to combine the use of amines and thermal modification, with subsequent properties investigated for the treatment of spruce (Picea abies (L.) H. Karst) and beech (Fagus sylvatica L.). In this initial study, the combined effects of chemical treatments by tricine and bicine were investigated with thermal modification. Along with some preliminary data on mechanical properties, the modifications which appeared in the wood structure were evaluated by infrared spectroscopy and biological studies according to EN113 and EN117 methodologies. The hierarchal study interpretation of FTIR suggested interactions between the bicine or tricine and the wood, which was partly supported by the analysis of volatile organic compounds (VOC), though other tests were not as conclusive. The potential of the method warrants further consideration, which will be described. Validerad;2022;Nivå 2;2022-05-30 (hanlid);Funder: COST Action FP1407;Part of special issue: Performance and Modification of Wood and Wood-Based Materials

The effects of thermal modification have been well established, particularly in terms of reductions in mechanical performance. In recent years, there has been an increase in studies related to the Maillard reaction. More commonly associated with food chemistry, it involves the reaction of amines and reducing sugars during cooking procedures. This paper has attempted to combine the use of amines and thermal modification, with subsequent properties investigated for the treatment of beech (Fagus sylvatica). In this initial study, the combined effects of chemical treatments by tricine and bicine were investigated with thermal modification. Along with some preliminary data on mechanical properties, the modifications which appeared in the wood structure were evaluated by infrared spectroscopy. After the treatment about 6-7 % of WPG was identified in treated samples, but further thermal treatment decreased the WPG to about 5%. The modifications appearing in the spectra were mostly related to increase of the intensities of the bands assigned to C=O groups but also to N-H and C-N groups, with shifting of some bands to higher wavenumber values.

The change, over time, in density, longitudinal modulus of elasticity, shear modulus and chemical structure of Scots pine (Pinus sylvestris) under thermal treatment (110, 120 and 140ºC) was evaluated. The determinations of the specific changes were carried out by means of impulse excitation, ultrasonic time-of-flight and near infrared spectroscopy. The results show, that the stiffness and density decrease was linear with time, with no evidence of a slowing rate of degradation even at 140ºC, after loss of more than half the original wood stiffness and more than a quarter of the original mass. At all temperatures the ratio between the longitudinal modulus and shear modulus was unchanged by the treatment for individual samples and the stiffness change was proportional to mass loss irrespective of the temperature and time. Examination of the NIR spectra revealed modifications in the amorphous carbohydrates structure and small changes in the lignin structure.