SORPTION AND SURFACE ENERGY PROPERTIES OF THERMALLY MODIFIED SPRUCE WOOD COMPONENTS

被引:2
作者
Kallbom, Susanna [1 ]
Altgen, Michael [2 ,3 ]
Militz, Holger [2 ]
Walinder, Magnus [1 ]
机构
[1] KTH Royal Inst Technol, Div Bldg Mat, SE-10044 Stockholm, Sweden
[2] Georg August Univ Gottingen, Wood Biol & Wood Prod, DE-37077 Gottingen, Germany
[3] Aalto Univ, Dept Bioprod & Biosyst, FI-00076 Aalto, Finland
来源
WOOD AND FIBER SCIENCE | 2018年 / 50卷 / 03期
基金
瑞典研究理事会;
关键词
Thermally modified wood; dynamic vapor sorption (DVS); inverse gas chromatography (IGC); Norway spruce; surface energy; acid-base properties; INVERSE GAS-CHROMATOGRAPHY; ACID-BASE INTERACTIONS; HEAT-TREATMENT; RELATIVE-HUMIDITY; FIBERS; ADSORPTION; PRESSURE; BEHAVIOR; HYGROSCOPICITY; IMPROVEMENT;
D O I
10.22382/wfs-2018-033
中图分类号
S7 [林业];
学科分类号
0829 ; 0907 ;
摘要
The objective of this work is to study the water vapor sorption and surface energy properties of thermally modified wood (TMW) components, ie wood processing residuals in the form of sawdust. The thermal modification was performed on spruce wood components using a steam-pressurized laboratoryscale reactor at two different temperature (T) and relative humidity (RH) conditions, T = 150 degrees C and RH = 100% (TMW150), and T = 180 degrees C and RH = 46% (TMW180). A dynamic vapor sorption (DVS) technique was used to determine water vapor sorption isotherms of the samples for three adsorption-desorption cycles at varying RH between 0% and 95%. Inverse gas chromatography (IGC) was used to study the surface energy properties of the samples, including dispersive and polar characteristics. The DVS results showed that the EMC was reduced by 30-50% for the TMW samples compared with control samples of unmodified wood (UW) components. A lower reduction was, however, observed for the second and third adsorption cycles compared with that of the first cycle. Ratios between EMC of TMW and that of UW samples were lower for the TMW180 compared with the TMW150 samples, and an overall decrease in such EMC ratios was observed at higher RH for both TMW samples. The IGC results showed that the dispersive contribution to the surface energy was higher at lower surface coverages, ie representing the higher energy sites, for the TMW compared with the UW samples. In addition, an analysis of the acid-base properties indicated a higher KB than KA number, ie a higher basic than acidic contribution to the surface energy, for all the samples. A higher KB number was also observed for the TMW compared with the UW samples, suggested to relate to the presence of ether bonds from increased lignin and/or extractives content at the surface. The KB was lower for TMW180 compared with TMW150, as a result of higher modification temperature of the first, leading to cleavage of these ether bonds.
引用
收藏
页码:346 / 357
页数:12
相关论文
共 63 条
[1]   The effect of air plasma treatment at atmospheric pressure on thermally modified wood surfaces [J].
Altgen, Daniela ;
Avramidis, Georg ;
Vioel, Wolfgang ;
Mai, Carsten .
WOOD SCIENCE AND TECHNOLOGY, 2016, 50 (06) :1227-1241
[2]   Influence of process conditions on hygroscopicity and mechanical properties of European beech thermally modified in a high-pressure reactor system [J].
Altgen, Michael ;
Militz, Holger .
HOLZFORSCHUNG, 2016, 70 (10) :971-979
[3]   Wood moisture content during the thermal modification process affects the improvement in hygroscopicity of Scots pine sapwood [J].
Altgen, Michael ;
Hofmann, Tamas ;
Militz, Holger .
WOOD SCIENCE AND TECHNOLOGY, 2016, 50 (06) :1181-1195
[4]   Wood degradation affected by process conditions during thermal modification of European beech in a high-pressure reactor system [J].
Altgen, Michael ;
Willems, Wim ;
Militz, Holger .
EUROPEAN JOURNAL OF WOOD AND WOOD PRODUCTS, 2016, 74 (05) :653-662
[5]   Strength properties and dimensional stability of particleboards with different proportions of thermally treated recycled pine particles [J].
Andrade, Paulo Ivan ;
Araujo, Solange de Oliveira ;
Neiva, Duarte Miranda ;
Vital, Benedito Rocha ;
Oliveira Carneiro, Angelica De Cassia ;
Gominho, Jorge ;
Pereira, Helena .
HOLZFORSCHUNG, 2016, 70 (05) :467-474
[6]  
[Anonymous], 1984, WOOD CHEM ULTRASTRUC, DOI DOI 10.1515/9783110839654
[7]   Effect of relative humidity on thermal degradation of Norway spruce (Picea abies) wood [J].
Borrega, Marc ;
Karenlampi, Petri P. .
JOURNAL OF WOOD SCIENCE, 2008, 54 (04) :323-328
[8]   Investigation on the surface properties of chemically modified natural fibers using inverse gas chromatography [J].
Cordeiro, Nereida ;
Ornelas, Mariana ;
Ashori, Alireza ;
Sheshmani, Shabnam ;
Norouzi, Hor .
CARBOHYDRATE POLYMERS, 2012, 87 (04) :2367-2375
[9]   Surface energy determinations of wood: Comparison of methods and wood species [J].
de Meijer, M ;
Haemers, S ;
Cobben, W ;
Militz, H .
LANGMUIR, 2000, 16 (24) :9352-9359
[10]   ADSORPTION OF NORMAL-ALKANES AT ZERO SURFACE COVERAGE ON CELLULOSE PAPER AND WOOD FIBERS [J].
DORRIS, GM ;
GRAY, DG .
JOURNAL OF COLLOID AND INTERFACE SCIENCE, 1980, 77 (02) :353-362