Kinetic color analysis for assessing the effects of borate and glycerol on thermal modification of wood
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The effects of borate and glycerol impregnation of Douglas-fir heartwood prior to open-air oven thermal modification at 160–200 °C for 2–4 h on wood color were measured. These materials were used to analyze the effects of modifying agents on thermal decomposition of wood by color nondestructive assessments. Kinetic analysis using time–temperature superposition and the horizontal shift factor were employed to quantify color changes. Lightness values were significantly affected by heating time and temperature, while red/green and yellow/blue values were significantly affected by pretreatments and thermal modification temperatures. Total color differences tended to increase with heating temperature and time. The calculated values of the apparent activation energy on non-impregnated, borate-impregnated and glycerol-impregnated wood ranged from 94.9 to 126.4 kJ/mol, 46.5 to 74.3 kJ/mol and 54.3 to 79.7 kJ/mol, respectively. The results suggest that borate and glycerol decreased the apparent activation energy of thermal degradation reactions and could function as a catalyst to accelerate thermal modification. Time–temperature superposition color kinetic analysis could be used to assess the effects of modifying agents on thermal decomposition.
The senior author is grateful for the support of National Natural Science Foundation of China (NSFC) No. 31400500.
- Esteves BM, Pereira HM (2009) Wood modification by heat treatment: a review. BioResources 4(1):370–404Google Scholar
- Esteves BM, Doningos IJ, Pereira HM (2008a) Pine wood modification by heat treatment in air. BioResources 3(1):142–154Google Scholar
- Fengel D, Wegener G (1989) Wood: chemistry, ultrastructure, reactions. Walter de Gruyter, Berlin, p 26Google Scholar
- Luo S, Cao J, Wang X (2013) Investigation of the interfacial compatibility of PEG and thermally modified wood flour/polypropylene composites using the stress relaxation approach. BioResources 8(2):2064–2073Google Scholar
- Sandberg D, Kutnar A, Mantanis G (2018) Wood modification technologies—a review. Forest 10:895–908Google Scholar
- Toshimi H (1995) Kinetics of pyrolysis of wood and cellulose. Mokuzai Gakkaishi 41(10):879–886Google Scholar
- Tuong VM, Li J (2010) Effect of heat treatment on the change in color and dimensional stability of acacia hybrid wood. BioResources 5(2):1257–1267Google Scholar
- Yan L, Chen Z (2016) Dynamic mechanical analysis of viscoelastic properties of heat treated glycerol-impregnation poplar wood. International research group on wood protection document no. IRG/WP/16-40732Google Scholar
- Yan L, Morrell JJ (2015) Mold and decay resistance of thermally modified Douglas-fir heartwood. For Prod J 65(5/6):272–277Google Scholar