Promotion effect of NP fire retardant pre-treatment on heat-treated poplar wood. Part 1: color generation, dimensional stability, and fire retardancy

Abstract Heat treatment (HT) enhances various properties of wood (W), but it takes a relatively long time and WHT is a source of fire hazard. To improve the properties of WHT, Populus beijingensis W. Y. Hsu wood was impregnated with nitrogen-phosphorus (NP) fire retardant (10% aqueous solution) and the effects of the combined NP treatment and HT were observed. Control groups included native wood and samples from WHT200°C, 120 min and WHT220°C, 120 min. The surface color, dimensional stability, and combustion properties of the treated samples were examined. NP pre-treatment intensified the effectivity of HT150°C, where the treatment time decreased by 75%. The decomposition and catalytic dehydration of NP treatment enhanced the dimensional stability and darkened the wood surface. After HT, the NP fire retardant was transformed from dispersive particles into a uniform layer on the inner surfaces of wood. The heat release rate (HRR) decreased by 60.3% and the residual mass (RM) increased by 61.1% in WNP, HT compared to normal WHT200°C poplar.

[1]  U. Westermark,et al.  Effects of borate impregnation on the response of wood strength to heat treatment , 2005, Wood Science and Technology.

[3]  H. Militz,et al.  2 Heat treatment of wood by the PLATO-Process , 2000 .

[4]  S. Pang,et al.  Changes in chemistry, color, dimensional stability and fungal resistance of Pinus radiata D. Don wood with oil heat-treatment , 2011 .

[5]  Michael Rosenthal,et al.  Calorific value of selected wood species and wood products , 2012, European Journal of Wood and Wood Products.

[6]  Helena Pereira,et al.  Wood modification by heat treatment: a review. , 2009 .

[7]  M. Pétrissans,et al.  XPS characterization of wood chemical composition after heat‐treatment , 2006 .

[8]  H. Militz,et al.  MICROSTRUCTURAL AND PHYSICAL ASPECTS OF HEAT TREATED WOOD . PART 1 , 2006 .

[9]  H. R. Taghiyari.  Study on the effect of nano-silver impregnation on mechanical properties of heat-treated Populus nigra , 2011, Wood Science and Technology.

[10]  M. Pétrissans,et al.  Wettability of Heat-Treated Wood , 2003 .

[11]  M. Budakçı,et al.  Surface roughness and brightness of scots pine (Pinus sylvestris) applied with water-based varnish after densification and heat treatment , 2015, Journal of Wood Science.

[12]  Xiaoteng Zhang,et al.  Effect of nitrogen–phosphorus fire retardant blended with Mg(OH)2/Al(OH)3 and nano‐SiO2 on fire‐retardant behavior and hygroscopicity of poplar , 2014 .

[13]  S. Korkut,et al.  The effects of heat treatment on some technological properties of Scots pine (Pinus sylvestris L.) wood. , 2008, Bioresource technology.

[14]  G. Janin,et al.  La Mesure de Couleur: Une Méthode d’Etude et d’Optimisation des Transformations Chimiques du Bois Thermolysé , 1991 .

[15]  D. Aydemir,et al.  THE DENSITY, COMPRESSION STRENGTH AND SURFACE HARDNESS OF HEAT TREATED HORNBEAM (Carpinus betulus ) WOOD , 2009 .

[16]  P. Bekhta,et al.  Colour in short-term thermo-mechanically densified veneer of various wood species , 2014, European Journal of Wood and Wood Products.

[17]  Thomas Z. Fabian.  Fire Performance Properties of Solid Wood and Lignocellulose-Plastic Composite Deck Boards , 2014 .

[18]  S. Korkut,et al.  Evaluation of physical and mechanical properties of wild cherry wood heat-treated using the thermowood process , 2015 .

[19]  .. T.O.Femi-Ola,et al.  Pre-freezing as a pre-treatment for thermal modification of wood. Part 2: surface properties and termite resistance , 2010 .

[20]  S. Hiziroglu,et al.  Effect of heat treatment on mechanical properties of hazelnut wood (Corylus colurna L.) , 2009 .

[21]  C. Krause,et al.  Structural analysis of heat-treated birch (Betule papyrifera) surface during artificial weathering , 2013 .

[22]  R. Guyonnet,et al.  The color measurement: A fast method to study and to optimize the chemical transformations undergone in the thermically treated wood , 1991 .

[23]  Yafang Yin,et al.  Changes of wood cell walls in response to hygro-mechanical steam treatment. , 2015, Carbohydrate polymers.

[24]  André Pichette,et al.  A spectrocolorimetric and chemical study on color modification of heat-treated wood during artificial weathering , 2012 .

[25]  Hamid Reza Taghiyari,et al.  Effects of nano-silver impregnation on brittleness, physical and mechanical properties of heat-treated hardwoods , 2012, Wood Science and Technology.

[26]  N. Ayrilmis,et al.  Properties of solid wood and laminated wood lumber manufactured by cold pressing and heat treatment , 2014 .

[27]  Danica Kačíková,et al.  Effects of thermal treatment on chemical, mechanical and colour traits in Norway spruce wood. , 2013, Bioresource technology.

[28]  K. Umemura,et al.  Kinetic analysis of color changes in keyaki (Zelkova serrata) and sugi (Cryptomeria japonica) wood during heat treatment , 2013, Journal of Wood Science.

[29]  C. Olarescu,et al.  COLOR CHANGE — MASS LOSS CORRELATION FOR HEAT-TREATED WOOD , 2014 .

[30]  P. Pasanen,et al.  Comparison of VOC emissions between air-dried and heat-treated Norway spruce (Picea abies), Scots pine (Pinus sylvesteris) and European aspen (Populus tremula) wood , 2010 .

[31]  S. Korkut,et al.  Effect of thermal treatment on the swelling and surface roughness of common alder and wych elm wood , 2015, Journal of Forestry Research.

[32]  M. D’Auria,et al.  Thermal treatment modifies the calorific value and ash content in some wood species , 2015 .

[33]  P. Vallittu,et al.  Effect of heat treatment of wood on the morphology, surface roughness and penetration of simulated and human blood. , 2014, Bio-medical materials and engineering.

[34]  D. Korkut,et al.  The effects of heat treatment on physical properties and surface roughness of red-bud maple (Acer trautvetteri Medw.) wood. , 2008, Bioresource technology.

[35]  L. Awoyemi.  Determination of optimum borate concentration for alleviating strength loss during heat treatment of wood , 2007, Wood Science and Technology.

[36]  Demiao Chu,et al.  Synthesis of fire retardants based on N and P and poly(sodium silicate-aluminum dihydrogen phosphate) (PSADP) and testing the flame-retardant properties of PSADP impregnated poplar wood , 2016 .

[37]  S. Yıldız,et al.  Changes in surface and mechanical properties of heat treated wood during natural weathering , 2014 .

[38]  Demiao Chu,et al.  Analysis of Gas Chromatography-Mass Spectrometry Coupled with Dynamic Headspace Sampling on Volatile Organic Compounds of Heat-Treated Poplar at High Temperatures , 2016 .

[39]  M. Thévenon,et al.  Development of new wood treatments combining boron impregnation and thermo modification: effect of additives on boron leachability , 2014, European Journal of Wood and Wood Products.

[40]  M. Jarvis,et al.  Effects of preboiling on the acidity and strength properties of heat-treated wood , 2009, Wood Science and Technology.

[41]  H. Militz,et al.  Characterisation of thermally modified wood: molecular reasons for wood performance improvement , 1998, Holz als Roh- und Werkstoff.

[42]  S. Hiziroglu,et al.  Effects of heat treatment and surface roughness on bonding strength , 2012 .

[43]  Ö. Ünsal,et al.  The Effects of Heat Treatment with the ThermoWood® Method on the Equilibrium Moisture Content and Dimensional Stability of Wild Cherry Wood , 2015 .

[44]  C. Hill,et al.  Wood Modification: Chemical, Thermal and Other Processes , 2006 .

[45]  H. R. Taghiyari.  Effects of heat-treatment on permeability of untreated and nanosilver-impregnated native hardwoods , 2013 .

[46]  S. Hiziroglu,et al.  Evaluation of hardness and surface quality of different wood species as function of heat treatment , 2014 .

[47]  P. Bekhta,et al.  Effect of High Temperature on the Change in Color, Dimensional Stability and Mechanical Properties of Spruce Wood , 2003 .

[48]  Li Jian,et al.  Analysis and characterization of dimensional stability and crystallinity of heat-treated Larix spp. , 2010 .

[49]  Emília Hroncová,et al.  The influence of spruce wood heat treatment on its thermal stability and burning process , 2014, European Journal of Wood and Wood Products.

[50]  H. S. Kol,et al.  The thermal conductivity of fir and beech wood heat treated at 170, 180, 190, 200, and 212°C , 2011 .

[51]  L. Awoyemi,et al.  Pre-freezing as a pre-treatment for thermal modification of wood. Part 2: surface properties and termite resistance , 2010, Journal of the Indian Academy of Wood Science.

[52]  Qingwen Wang,et al.  Effects of chemical modification on the mechanical properties of wood , 2013, European Journal of Wood and Wood Products.

[53]  Junliang Liu,et al.  Changes in dimensional stability and mechanical properties of Eucalyptus pellita by melamine–urea–formaldehyde resin impregnation and heat treatment , 2013, European Journal of Wood and Wood Products.

[54]  C. Brischke,et al.  Quality control of thermally modified timber: Interrelationship between heat treatment intensities and CIE L*a*b* color data on homogenized wood samples , 2007 .

[55]  J. Weiland,et al.  Study of chemical modifications and fungi degradation of thermally modified wood using DRIFT spectroscopy , 2003, Holz als Roh- und Werkstoff.