bluuebunny/crossref_metadata_2025 huggingface dataset:
Reactions of Lignin with Cyanamide Activated Hydrogen Peroxide. Part 3. The Degradation of Pine Kraft Lignin
Authors: Kadla John F. , Chang Hou-min
Published: September 2004

The oxidation of pine kraft lignin by alkaline hydrogen peroxide and cyanamide activated hydrogen peroxide
was studied. Over 70% of the kraft lignin was degraded and solublized in the presence of
cyanamide as compared to less than 20% by hydrogen peroxide alone. A large decrease in the phenolic
hydroxyl and methoxyl content,as well as an increase in the carboxylic acid content was also observed
in the insoluble residue. Analyses of the low molecular weight degradation products revealed extensive
oxidation of the kraft lignin had occurred,consistent with the ring-opening reactions observed in our previous
studies using lignin model compounds.
Kinetics of ASAM and Kraft Pulping of Eucalypt Wood (Eucalyptus globulus)
Authors: Miranda Isabel , Pereira Helena
Published: September 2004

The kinetics of ASAM and kraft pulping of eucalypt wood (Eucalyptus globulus) were studied in relation
to delignification and polysaccharide removal. In comparison to kraft, ASAM pulping had lower
mass losses and delignification for the same temperature and reaction times (59.2% at Kappa 25 vs
50.0% at Kappa 17, at 180°C). The ASAM pulps have a higher brightness. ASAM pulping had a short
initial period with no mass loss and lignin removal, followed by two reaction phases: a main phase where
61% of lignin was removed (at 180°C) and a subsequent final phase. In comparison to kraft, the main
delignification rates of ASAM pulping were approximately 2.5 slower (at 180°C, −1.8 × 10−2 min−1 for
ASAM and −4.2 × 10−2 for kraft pulping), and the calculated Arrhenius activation energies were higher
(132.4 kJ mol−1 and 83.5 kJ mol−1, respectively). The loss of cellulose was relatively small (12.5 %)
and lower than in kraft pulps.
Adsorption of Liquids and Swelling of Wood. Part VI. Saturated Amounts and Some Thermodynamic Values of Adsorption
Authors: Morisato Kei , Ishimaru Yutaka , Urakami Hiroyuki
Published: September 2004

To understand the swelling phenomenon of wood in liquids,the saturated amount of adsorption of liquids
onto wood and the standard free energy changes of the adsorption were determined. The saturated
amount of adsorption obtained by regression for several liquids decreased with increasing molecular size
of the solvents. The mechanism of wood swelling is discussed systematically taking all the liquids examined
in previous experiments into account. Since methanol molecules require more energy for release
from cohesive interactions within bulk liquids in the adsorption onto pre-swollen wood,the values of
free energy change of adsorption for methanol were lower than the values for acetone,although the relative
swelling with methanol was higher. These results suggest that although the cohesive interaction
within the bulk liquids reduces adsorptivity,the phenomenon of wood swelling is influenced not only by
monolayer adsorption but also by multilayer adsorption. Therefore,the cohesive interaction within the
bulk liquids reduces adsorptivity but enhances the condensation which strongly influences the swelling
of wood.
The Analysis of Dimensional Changes Due to Chemical Treatments and Water Soaking for Hinoki (Chamaecyparis obtusa) Wood
Authors: Ohmae Kosuke , Minato Kazuya , Norimoto Misato
Published: September 2004

To clarify tangential and radial dimensional changes in hinoki (Chamaecyparis obtusa) wood by ten
kinds of treatments and successive water soaking, a vector expression on the tangential-radial coordinates
was proposed and a new measure (ASE′) to evaluate the dimensional stability of wood was defined.
The ASE′ is expressed by 100(1 − Vs′
/Vu
) where Vu
is the volumetric swelling coefficient of untreated
wood and Vs′
is that of treated wood calculated on the basis of its oven-dried volume before treatment.
The results from formaldehyde treated, heat treated and steam treated wood showed large positive ASE′
values and the ratio of radial swelling to tangential swelling (swelling anisotropy) of these treated woods
decreased with increasing weight percent gain or weight loss. The results from acetylated wood, wood
impregnated with polyethylene glycol and wood treated with a low molecular weight phenol-formaldehyde
resin showed either small positive or negative ASE′ values, and those of wood treated with propylene
oxide showed large negative values. The swelling anisotropy of treated woods accompanied by cell
wall bulking was larger than that of untreated wood. The swelling anisotropy decreased when the cell
lumen was filled with a hydrophobic resin (WPC-MMA), and increased when the cell lumen was filled
with a hydrophilic resin (WPC-HEMA).
Using UV-Microscopy to Study Diffusion of Melamine-Urea-Formaldehyde Resin in Cell Walls of Spruce Wood
Authors: Gindl Wolfgang , Dessipri Eugenia , Wimmer Rupert
Published: September 2004

Using UV-microscopy, absorbance spectra of a cured melamine-urea-formaldehyde resin and secondary
cell walls of spruce wood glued with this resin were determined. Analysis of the spectra showed that
peaks characteristic for both coniferous lignin and melamine resin were present in cell walls of tracheids
embedded in the resin. A quantitative estimate indicated a melamine content of the resin embedded
cell walls of 6.2%. It could be demonstrated that UV-microscopy is well suited for the investigation
of resin diffusion into the wood cell wall.
Volatile Organic Compounds Emissions from Particleboard Veneered with Decorative Paper Foil
Authors: Wiglusz R. , Nikel G. , Igielska B. , Sitko E.
Published: September 2004

The indoor environment can constitute a serious health
hazard if buildings are not properly constructed and finished.
Building, finishing and furnishing materials may emit
a large number of volatile organic compounds (VOCs) into
the indoor air. That wood-composite products are among
the sources of formaldehyde emissions is well documented.
Up until now very little has been known about the emission
of VOCs from wood-composite products (Merrill and Steiber
1987; Levin 1992; Sundin and Edenholm 1992; Catananti
et al. 1993; Barry and Corneau 1999).
The aim of this work is the determination of VOC and
formaldehyde emissions from particleboard veneered with
decorative paper foil.
Intra- and Inter-Tree Variability of Moisture Content in Standing Sessile Oak (Quercus petraea Liebl.)
Authors: Constant T. , Nepveu G. , Huber F.
Published: September 2004

Knowledge about the moisture content of trees in the forest or wood yard is scarce. The variation of moisture content within and between 20 boles of sessile oak was investigated using 1543 measurements performed at three heights in each tree and along 4 radii. Five radial positions were defined: sapwood, outer, intermediate and inner heartwood, and the core piece including the pith. Results show that the average moisture content is highly dependent on the individual. The average moisture content was around 80%(oven-dried basis), but it ranges from 65% to 100%depending on the tree. This “tree” effect is discussed and examined using some general characteristics of the trees (region, stand structure, site quality, dendrometric and densitometric traits). Apart from age counted from pith, and the ratio of tree height vs. diameter, no strong correlation appears. Moderate variations in moisture content with radial position and height are also brought to the fore. The specific role of sapwood, which exhibits a more variable moisture content is discussed.
Depletion of CCA-C from Ground-Contact Wood: Results from Two Field Sites with Significantly Different Soils
Authors: Schultz T. P. , Nicholas D.D. , Pettry D. E.
Published: September 2004

Two field test sites with different soil types were selected. Analysis showed that the two soils had considerable between-site variation in texture, base saturation, acidity, levels of metals, and cation exchange capacity. The sites also had moderate differences in average seasonal temperatures and rainfall. Stakes, made from defect-free southern yellow pine (SYP) sapwood and measuring 19×19×559mm, were treated to about 0.40 pcf (6.4 kg/m3) with chromated copper arsenate (CCA-type C). The stakes were installed at the two sites and sets of ten or more samples pulled after 55 and 66 months of exposure. The depletion of the individual components (chromium, copper and arsenic, oxide basis) from below-ground sections of each stake was then determined. No significant site effect on depletion was observed despite the large contrasts in chemical and physical properties between the two soils. Of the individual components, copper generally had the least depletion on a pcf weight loss basis while the greatest loss was observed with arsenic in three of the four time/site sets. The exposure times examined had no influence on depletion.
The Organosolv Fractionation of Cork Components
Authors: Cordeiro Nereida , Neto Carlos Pascoal , Rocha Joao , Belgacem Mohamed N. , Gandini Alessandro
Published: September 2004

Extractive-free cork from Quercus suber L. was submitted to organosolv fractionation and the effects of different process variables, such as ethanol/water ratio, temperature, time and the presence of acidic or alkaline catalysts, were studied. The variation of the relative proportions of extracted components, as a function of the processing conditions, could thus be established. Whereas the addition of 0.1Macetic acid only increased the yield of extracted materials from about 15 to 23 %, the use of sodium hydroxide, at the same concentration, produced a jump to 76 %. In the case of the alkaline organosolv fractionation, an increase in process temperature, time and catalyst concentration led to an increase in the extraction yield, although in some cases this increase did not follow a sustained trend, as in the case of reaction time. Increasing the ethanol/water ratio led to a higher selectivity in favour of suberin extraction. Residual cork from different organosolv processes was characterised by FTIR and 13C solid-state NMR. The latter technique provided some valuable information about both process selectivity and cork morphology, particularly with respect to the positioning of suberin macromolecules in the cell wall.
Identification of New Hydroxy Fatty Acids and Ferulic Acid Esters in the Wood of Eucalyptus globulus
Authors: Freire C. S. R. , Silvestre A. J.D. , Neto C. Pascoal
Published: September 2004

The chemical composition of the dichloromethane extract of Eucalyptus globulus wood cultivated in Portugal was studied by gas chromatography-mass spectrometry, prior to and after alkaline hydrolysis. In addition to previously identified lipophilic extractives, 22 free or esterified compounds (14 fatty acids, 2 fatty alcohols and 6 aromatic compounds) were identified for the first time in E. globulus wood. One of these, ferulic acid, was esterified with three different fatty alcohols and with two α-hydroxyfatty acids. Some of the newly identified compounds, particularly the a-hydroxy-fatty acids are responsible for recently reported pitch problems during pulp production in a Portuguese mill. The differences found in the E. globulus chemical composition, when compared with published data, are expected to be related to variations in the location of growth and genetic factors.
The Pyridine-Catalysed Acylation of Pine Sapwood and Phenolic Model Compounds with Carboxylic Acid Anhydrides. Determination of Activation Energies and Entropy of Activation
Authors: Hill Callum A. S. , Papadopoulos A.N.
Published: September 2004

The reaction activation energies and entropies have been determined for the catalysed reaction of pyridine swollen pine sapwood samples and phenolic model compounds (in solution) with a homologous series of carboxylic acid anhydrides. With wood samples, the activation energy (Ea) was largest for the reaction of ethanoic anhydride (ca. 40 kJ mol−1), and decreased as the molecular weight of the anhydride increased (to ca. 10 kJ mol−1 with hexanoic anhydride). With the model compounds, there was no substantial evidence for such a relationship between molecular weight of anhydride and Ea. Values for the entropy of activation for reaction with wood were on the order of −300 J K−1 mol−1, whereas values for reaction with the model compounds were generally on the order of −−220 to −260 JK−1 mol−1. The activation energies of diffusion (Eadiff) for the anhydride series in Corsican and Scots pine have also been determined, these varied from ca. 7 to 19 kJ mol−1. No correlation was found between Eadiff and anhydride, nor between Eadiff and wood species. The results are interpreted by considering the void space created around the reactive hydroxyl groups through swelling of the cell wall with pyridine.
Klason Lignin: Modifications to Improve the Precision of the Standardized Determination
Authors: Schwanninger Manfred , Hinterstoisser Barbara
Published: September 2004

The lignin content in wood is generally determined with a standardized method. It is shown that with minor modifications, e.g., particle size, temperature and adherence to handling times, the standard deviation could be decreased substantially. Pooled standard deviations of 0.045 %, based on 30 determinations in immediate succession, and 0.11%, based on 400 determinations in randomized order, were obtained, which are well qualified for the calibration of secondary analytical methods such as NIR or Raman spectrometry. As a consequence of finer grinding, an identical sample can be used for lignin determination and for investigations in the mid infrared region without regrinding or fractionating.
Softwood Bark Pyrolysis Oil-PF Resols. Part 1. Resin Synthesis and OSB Mechanical Properties
Authors: Amen-Chen Carlos , Riedl Bernard , Wang Xiang-Ming , Roy Christian
Published: September 2004

Bark residues generated by the pulp and paper and wood industries represent a threat to the environment due to leaching of chemicals such as phenolics and resin acids which are being currently regulated by governments. Vacuum pyrolysis of resinous bark produces phenolic-rich oils which represent a potential raw material to replace petroleum-based phenol presently used in the formulation of wood adhesive resols.

Resols with different levels of phenol replacement by phenolic pyrolysis oils, formaldehyde to phenolics molar ratios and sodium hydroxide to phenolics molar ratios were synthesized. Strandboards werepreparedandtheirmechanicalandphysicalpropertiessuchasmodulusofrupture(MOR),modulus of elasticity (MOE), dry and 2-hour boil internal bond (IB) and thickness swelling (TS) were evaluated.

Homogeneous panels bonded with resins having 25 and 50% by wt of pyrolysis oils replacing phenol exhibited comparable mechanical properties to those of panels made with a commercial surface resin under the same pressing conditions. Three-layer panels made with resins having 50 % by wt phenol replacement in the surface and 25% by wt phenol replacement in the core had mechanical properties above the requirements specified by the Canadian Standards CSAO437.0-93 for OSB products.
A Comparative CP/MAS 13C-NMR Study of the Supermolecular Structure of Polysaccharides in Sulphite and Kraft Pulps
Authors: Hult Eva-Lena , Larsson Per Tomas , Iversen Tommy
Published: September 2004

The supermolecular structure of polysaccharides in unbleached sulphite pulps and kraft pulps was investigated by CP/MAS 13C-NMR (Cross Polarisation Magic Angle Carbon-13 Nuclear Magnetic Resonance) in combination with spectral fitting. The cellulose crystallinity was found to be higher in the kraft pulps than in the sulphite pulps. Acellulose Iα to cellulose Iβ conversion was observed during kraft pulping but not during sulphite pulping. The sulphite pulps exhibited smaller lateral fibril aggregate dimensions than the kraft pulps. The spectral behaviour of the hemicelluloses in the sulphite pulps was different from that in the kraft pulps. The general observation is that the supermolecular structure of the polysaccharides in the investigated sulphite pulps is very similar to the structure observed in wood.
Fracture Behaviour of Modified Spruce Wood: A Study Using Linear and Non Linear Fracture Mechanics
Authors: Reiterer Alexander , Sinn Gerhard
Published: September 2004

The fracture properties of unmodified and modified (heat treatments under various conditions and acetylation) sprucewood are investigated using the wedge splitting test. Fracture parameters measured include critical stress intensity factor and specific fracture energy under Mode I loading and specific fracture energy under Mode III loading. The Mode I fracture properties are reduced by all kinds of modification. However, acetylation leads to a reduction of only 20%whereas heat treatments reduce the properties to a much greater extent, approximately 50%to 80%. The Mode III fracture properties are influenced less. SEM pictures of the fracture surfaces support the described findings.
Instabilities in the System NMMO/Water/Cellulose (Lyocell Process) Caused by Polonowski Type Reactions
Authors: Rosenau Thomas , Potthast Antje , Hofinger Andreas , Sixta Herbert , Kosma Paul
Published: September 2004

Polonowski type degradation reactions are a major reason for the frequently observed instability of solutions of cellulose in N-methylmorpholine-N-oxide monohydrate (NMMO, 1). The degradation is induced by degradation products of cellulose and NMMO generated in situ in the Lyocell system. The presence of both an amine component, such as morpholine or N-methylmorpholine, and an acid component is required for the decomposition process to proceed. The latter might be a low-molecular-weight compound, such as formic acid, acetic acid or gluconic acid, or also a high-molecular-weight acid, such as polyglucuronic acid or ion exchange resin.
Effects of Retention and Distribution of Fire Retardant Chemical on Performance of Fire Retardant Treated China Fir (Cunninghamia lanceolata) Wood
Authors: Chuang Horng-Bin , Wang Song-Yung
Published: September 2004

This study investigates the effect of fire-retardant (FR) chemical retention and distributive percentage of FR chemical (DP) on FR performance of FR treated China fir (Cunninghamia lanceolata) wood. The specimens were treated with various concentrations of FR chemical solutions using a vacuum or full-cell process in order to obtain six different DP levels of FR treated woods with DP levels of 34 %, 48 %, 62 %, 76 %, 90%and 100 %.FR treated woods were tested in accordance with the third grade of surface FR performance as specified by the CNS 6532 standard. Results indicated that the minimum FR chemical retention for meeting the requirement of the third grade standard was 49.2 kg/m3 and 56.6 kg/m3 for 100% and 90% of DP level specimens, respectively. However, when the specimens exhibited 62%
∼ 34% of DP level and a FR chemical retention up to 100.5–115.8 kg/m3 they did not qualify for the third grade standard. The factors of surface FR performance were influenced significantly by the DP level of specimens, the factor of tl (flame lingering time index of material) of FR treated wood could be considered the most sensitive indicator for meeting the requirement of the third grade standard in this study.
Examination of the Penetration of Polymeric Methylene Di-Phenyl-Di-Isocyanate (pMDI) into Wood Structure Using Chemical-State X-Ray Microscopy
Authors: Buckley C. J. , Phanopoulos C. , Khaleque N. , Engelen A. , Holwill M.E. J. , Michette A.G.
Published: September 2004

The penetration behaviour of isocyanate-based wood resins was evaluated using x-ray microscopy. Aspen wood pieces were bonded together in a controlled manner. These were embedded in a methacrylate-based resinand thin sections were prepared, cut from the transverse face of thewoodcomposite. X-ray images of these sections were prepared at several selected x-ray energies to allow the isocyanate, cellulose, lignin and the embedding agent distributions to be mapped. The isocyanate resin was found to penetrate deeply into the wood. The resin enters large cell lumen, and wicks along the inner cell wall surfaces. The resin accesses connected cells via connecting pits, which become filled with the resin. The affinity of the isocyanate to the inner surfaces of the large cells is probably due to the hydrophobicity of these surfaces. Isocyanate resins do not penetrate into the smaller parenchyma and tracheid cells and indeed do not even wet the inner surfaces of these cells where isocyanate entry has been allowed due to damage of the cell at the macroscopic surface of the wood. If isocyanates penetrate into the wood-cell walls of the large cells, the concentration in the cell walls has been determined to be less than 2%of the bulk concentration. This lower limit is the sensitivity limit imposed by photon statistics in the data.
Weight Loss and Cell Wall Degradation in Rubberwood Caused by Sapstain Fungus Botryodiplodia theobromae
Authors: Florence E. J. M. , Gnanaharan R. , Singh P. Adya , Sharma J. K.
Published: September 2004

Botryodiplodia theobromae is the predominant fungus causing sapstain in rubberwood in Kerala, India.
The fungus causes up to 12.2 percent weight loss in rubberwood over a period of sixteen weeks.
Transmission Electron Microscopy (TEM) of sapstained rubberwood provided evidence on hyphal
invasion of cells by B. theobromae through the pit region, facilitated by its ability to degrade pit
membranes. The study also revealed that B. theobromae caused degradation of lignified cell walls by
erosion of the cell wall surfaces of wood elements.
Changes of EPR Spectra of Wood Impregnated with Copper-Based Preservatives during Exposure to Several Wood-Rotting Fungi
Authors: Humar M. , Petrič M. , Pohleven F. , Šentjurc M. , Kalan P.
Published: September 2004

The tolerance of various fungi against copper was examined. For this purpose, we impregnated Norway spruce (Picea abies) specimens with two different aqueous solutions: copper(II) octanoate with ethanolamine or copper(II) sulfate (cCu= 1.0 × 10−2mol/l). Impregnated and unimpregnated test specimens were then exposed to brown rot fungiAntrodia vaillantiiandGloeophyllum trabeumor to white-rot fungiSchizophyllum communeandTrametes versicolor. After 2, 4, 6 and 12 weeks of exposure Electron Paramagnetic Resonance, Atomic Absorption Spectroscopy and mass loss measurements were performed. The results indicate thatA. vaillantii, G. trabeumandT. versicolortransform copper(II) sulfate in wood into non-soluble, and therefore non-toxic, copper oxalate. The intensity of this reaction depends on the amount of excreted oxalic acid and was the highest forA. vaillantiiand the lowest forT. versicolor. In the presence of ethanolamine, formation of insoluble copper oxalate was not possible and therefore, decay could not proceed. The major portion of copper remained in the wood and only minor amounts were in some cases translocated into nutrient media.
Direct Effects of Wood Characteristics on Pulp and Handsheet Properties of Eucalyptus globulus
Authors: Wimmer R. , Downes G.M. , Evans R. , Rasmussen G. , French J.
Published: September 2004

Fibre length, microfibril angle and wood density were measured in eight-year-old Eucalyptus globulus
clones planted on three different sites. Samples were chipped and pulped, and the pulps beaten prior to
preparation of 60g/m2 handsheets. Eleven physical handsheet properties, together with pulp freeness,
were measured using standard methods. Direct relationships between wood properties and pulp/paper
properties were studied using path analysis.

Fibre length had a strong, direct effect on tear index, bending stiffness, freeness, pulp yield and active
alkali consumption. Wood density was a strong predictor of most handsheet properties: high density
woods produced bulkier, more porous sheets with higher bending stiffness, while lower density woods
produced smoother, denser sheets with higher tensile strength.The effect of microfibril angle was small
and more evident in handsheets made from beaten pulp.
Pinus pinaster Oleoresin in Plus Trees
Authors: Arrabal C. , Cortijo M. , de Simón B. Fernández , García-Vallejo M.C. , Cadahía: E.
Published: September 2004

The present paper establishes the relationship between certain components of oleoresin and the
character of a tree as high producer (plus tree). The composition of the oleoresin (monoterpenes,
sesquiterpenes, neutral diterpenes and resin acids) of Pinus pinaster in plus trees was studied by gaschromatography/mass spectrometry. The main components of the monoterpenes are α-pinene, β-pinene, limonene + β-phellandrene; of the sesquiterpenes β-caryophylene and longifolene; of neutral
diterpenes isoabienol, abienol, isopimaral, pimaral, 11,13-labdien-8-ol and of resin acids levopimaric
+ palustric, neoabietic, abietic, isopimaric, pimaric, dehydroabietic, sandaracopimaric and 7,13,15
abietatrienoic acid. The components which enable us to distinguish between plus and control trees are
myrcene and noracid 1 at a level of significance of 1%, and abienol and dehydroabietic acid at 5%. The
composition of diterpenes permits a certain approach to distinguish between control and plus trees.
Determination of Polyphenolic Content of Bark Extracts for Wood Adhesives
Authors: Tahir P. Md. , Musgrave O.C. , Ashaari Z.
Published: September 2004

The phenolic content of condensed tannins varies considerably, depending on the method of determination.
Even though the Stiasny precipitation number has been commonly used to estimate the amount
of reactive tannin towards formaldehyde, particularly in adhesive applications, this estimation alone is
not sufficient. In this study two methods of determining the amount of reactive tannin towards
formaldehyde were examined. These were (1) the reactivity towards formaldehyde or the Stiasny
precipitation number, and (2) the formaldehyde uptake. Five different types of tannin were examined
from Rhizophora mucronata, P. radiata, mimosa, quebracho and chestnut. The study indicates that the
phenolic content in tannin can be better estimated by determining both the Stiasny number and the
amount of formaldehyde uptake. High correlation (r2 = 0.905) was detected between the two methods.
The study also revealed that hot water extracts of R. mucronata contain relatively small amounts of
reactive polyphenols and are less reactive than sulfite extracts. The consumption of formaldehyde by
this type of tannin was only 0.294 molecules per flavanoid unit. Similar to R. mucronata, the sulfite
extracts of P. radiata contain relatively high amounts of reactive polyphenols and reacted with substantially
higher amounts of formaldehyde per flavanoid unit, comparable to mimosa and quebracho
tannins. Nonetheless, the reactivity towards formaldehyde (gel time) of the latter tannins is muchlower,
despite their higher polyphenolic content. Of the two methods used to estimate the polyphenolic
content of bark extracts, the Stiasny number had a relatively higher correlation (r2 = 0.518) with gel
time than formaldehyde uptake (r2 = 0.345) did. The behaviour of these tannins in relation to their
reactivity and chemical structures is discussed.
Softwood Bark Pyrolysis Oil-PF Resols. Part 2. Thermal Analysis by DSC and TG
Authors: Amen-Chen C. , Riedl B. , Roy C.
Published: September 2004

Cure behavior of resins formulated with petroleum phenol replaced by 25 and 50 wt% of softwood
bark-derived pyrolysis oils, using various formaldehyde to phenolics molar ratios and alkalinity
content, was characterized by Differential Scanning Calorimetry (DSC). Kinetic parameters were
obtained by the Borchart-Daniels method and the model-free (Vyazovkin) method. Resins containing
up to 50% by wt of pyrolysis oils had slower cure kinetics and lower extent of condensation reaction
compared to a neat laboratory made phenol-formaldehyde resin. However, very similar kinetic curing
behavior to the standard resins was found for resols having 25% by wt of the petroleum phenol
replaced by the pyrolysis oils. Thermogravimetric analysis (TG) of cured pyrolysis oil-PF resins has
been done under nitrogen and air environments at a constant heating rate. Thermal behavior of resins
containing pyrolysis oils differed depending on the nature of the purge gas used in TG. Increasing the
amount of pyrolysis oils decreased the thermal resistance of the experimental resins.
Softwood Bark Pyrolysis Oil-PF Resols. Part 3. Use of Propylene Carbonate as Resin Cure Accelerator
Authors: Amen-Chen C. , Riedl B. , Wang X.-M. , Roy C.
Published: September 2004

Phenol-formaldehyde (PF) resols were prepared with different proportions of phenol replaced with
softwood bark pyrolysis oils under varying formaldehyde to phenolics molar ratios and sodium
hydroxide contents. Propylene carbonate (PC) was added to these adhesives to improve the cure of
resins. The cure behavior was characterized by differential scanning calorimetry (DSC). Cure kinetics
and amount of cure of the experimental resin were improved by adding PC to the resins. Low amounts
of PC were used (less than 1.5% of PC on a resin solid basis) to avoid premature gelling of the
adhesives. Results obtained by DSC suggested that PC catalyzed the resin cure reaction and also
participated in resin cross-linking reactions. Low percentages of PC, 0.5 and 1% on a resin solid basis,
were added to the experimental resins for bonding strandboards. These addition levels did not
significantly improve mechanical properties of strandboards. It is concluded that a PC addition level
of more than 1% by wt (on a resin solid basis) should be used to modify the mechanical properties of
panels bonded with pyrolysis oil-PF resins.
Characterization of Black Liquors from Soda-AQ Pulping of Reed Canary Grass (Phalaris arundinacea L.)
Authors: Feng Z. , Alén R. , Pakkanen H.
Published: September 2004

Reed canary grass (Phalaris arundinacea L.) was delignified in a laboratory-scale digester by conventional
soda-AQ pulping under varying conditions. The chemical composition of the corresponding
black liquors was analyzed with respect to their main organic constituents. The results showed that the
dry solids of the black liquors contained 33–34% lignin, 14–19% aliphatic carboxylic acids and 12–16% polysaccharides. No significant differences were found in the average molecular masses (M̄w

4700–5600 Da and M̄n
650–750 Da) of the dissolved lignins in these black liquors, although the
polydispersity (M̄w
/M̄n
) values (6.6–7.9) indicated that the molecular masses had a wide distribution.
Lignin clearly degraded in the black liquors as delignification proceeded. Of the monosaccharide
moieties detected in the polysaccharides, xylose was predominant, suggesting that xylan was a major
hemicellulose constituent in the black liquors.
Modification of the Nitrogen Content and C:N Ratio of Sitka Spruce Timber by Kiln and Air Drying
Authors: Payne C.
Published: September 2004

Loss of N from Sitka spruce timber was investigated by sampling battens before drying, after 5 and 41
days air drying, after exposure to a full kiln drying schedule and at 24 h intervals during kiln drying.
Undried sapwood and heartwood had similar total N content. Kiln drying significantly reduced total N
content of the sapwood and heartwood within the first 24 h of the drying schedule when wood
temperature was below 50°C. Tests using timber from trees felled at different times of the year and
grown in different locations with considerably different undried N content indicated a constant N loss
of approx 30% of the total as a result of kiln drying. No evidence of absolute N enrichment of
evaporation surfaces of battens was found, although a slight enrichment relative to wood within battens
did develop as a result of kiln drying. Air drying also reduced N content but to a lesser extent than kiln
drying, even after 41 days exposure. Nitrogen was lost more quickly from heartwood than sapwood
during air drying. Loss of N from the wood appears to be in a gaseous or vapour form which is suggested
to be through loss of naturally present ammonia and deamination of amino acids to produce further
ammonia. GC-MS analysis of gasses/vapours released by wood samples indicated that molecules of 17
amu, which may include ammonia, were liberated in relatively large quantities from undried heartwood
but not from partly kiln dried heartwood when heated. Sapwood released these molecules more
slowly and continued to do so following partial kiln drying possibly indicating a less volatile source.
Temperature gradients within battens during kiln drying were relatively small, with temperature
similar to that of the kiln air.
High Resolution Measurement of the Surface Layer Moisture Content during Drying of Wood Using a Novel Magnetic Resonance Imaging Technique
Authors: Rosenkilde A. , Glover P.
Published: September 2004

The moisture content profile in the surface layer of Scots pine (Pinus sylvestris) sapwood has been
measured using the MRI (Magnetic Resonance Imaging) technique.Anovel high-gradient permanent
magnet was used for the measurement of the moisture profile in the wood during the drying process,
giving a depth resolution of better than 20 μm. This paper demonstrates for the first time the possibility
of measuring the moisture content depth profile in the surface layer from raw state down to 4%
moisture content without removing the wood sample from the apparatus. The main advantage of this
technique and apparatus is a high resolution over a large field of view. It is possible to measure the
moisture content in the wood surface layer during drying up to a depth of 300 μm. A single moisture
content profile may be obtained in less than 5 min. Hence, more accurate dynamic drying information,
on a single sample, maybe achieved than with current techniques. In this preliminary studywe observed
that the wood cells at the surface had a moisture content higher than the equilibrium moisture content
for wood in the surrounding bulk air. We conclude that for a wood moisture content of above
approximately 50% the resulting profiles were almost flat from a depth of 90 μm and further into
the wood and in between the surface and 90 μm deep there was a steep gradient. Below 50% there was a
gradient in moisture content to at least 300 μm depth.
Longitudinal Permeability and Diffusivity of Steam in Beech Determined with a Wicke-Kallenbach-Cell
Authors: Mouchot N. , Zoulalian A.
Published: September 2004

To create a model of beech wood drying in the hygroscopic range, knowledge of longitudinal permeability
and diffusivity parameters of wet air in wood is needed. These data were obtained using a Wicke-Kallenbach-cell running in an open system and crossed either by an inert gas (nitrogen) or by two
streams of two inert gases (helium and nitrogen), that prevent the adsorption phenomena in wood.
Taking into account the relations between apparent and molecular diffusivities, the diffusivities of
steam could be calculated from those of helium. Longitudinal diffusivity and permeability increase
slightly with the moisture content of wood; the average values obtained at the ambient temperature
(20°C) for the axial diffusivity (8. 1. 10−6 m2/s) and for the axial permeability (2. 2. 10−11 m2) are
compatible with those reported in the literature for this species.
Characteristics of Attack of Coastal Timbers by Pselactus spadix (Herbst) (Col.: Curc.: Cossoninae) and an Investigation of its Life History
Authors: Oevering P. , Pitman A.J.
Published: September 2004

Pselactus spadix attack of marine timbers was characterised by circular emergence holes 1.48±0.05 mm in diameter and adult tunnels (1.49±0.34 mm) breaking through the wood surface. Larval tunnels measured 0.407–1.892 mm in diameter, initiated from adult tunnels and increased in diameter away from the adult tunnel terminating in frass free pupal chambers (1.6±0.3 mm × 3.5±0.7 mm). Observations of larval tunnel locations indicated oviposition occurred inside the adult tunnels. P. spadix life history was investigated in Scots pine (Pinus sylvestris) heartwood at 22±2 °C and 99±1% r.h. Mean adult longevity was 11.5±6.5 months, with mean post-mating longevity for males (11.7±2.9 months) significantly longer than for females (6.3±1.1 months). Adults of at least 2–3 months old were found mating in galleries, which, with observations of the larval tunnel pattern, indicated P. spadix can complete its life cycle without emerging from wood. Five larval instars were identified by measurement of 1722 head capsule widths and application of Dyar's law. Mean development time from 2nd instar to adult emergence was 70.5±6.9 weeks and pupation took 14.6±5.8 days. Development from 2nd instar to reproductive adult took between 17–20 months, with life cycle approximating 24 months at 22±2 °C and 99±1%
Bacterial Cellulose Production Using Monosaccharides Derived from Hemicelluloses in Water-Soluble Fraction of Waste Liquor from Atmospheric Acetic Acid Pulping
Authors: Uraki Y. , Morito M. , Kishimoto T. , Sano Y.
Published: September 2004

The water-soluble fraction (WS) from waste liquor of atmospheric acetic acid pulping was analyzed in order to explore its potential utilization as a carbon source for bacterial cellulose (BC) production. The unpurified WS that contained colored compounds had appreciable antibacterial activity and was therefore not used as a carbon source for BC production with the bacteria Acetobacter xylinum ATCC 10245 and 53582. However, the bacteria produced BC from purified WS of both fir and birch after activated carbon treatment. The yields of BC were much lower compared to those using glucose as a typical carbon source in the Hestrin-Schramm (HS) medium. In order to improve the cellulose production, monosaccharides derived from hemicellulose sugars in WS were modified. The WS from softwood was reduced by catalytic reduction, i.e. mannose, the major component of softwood monosaccharides derived from hemicelluloses, was converted to mannitol. In the case of hardwood WS, xylose was isomerized with glucose isomerase to xylulose. The yield of BC was considerably enhanced by both modifications of the WS. The yield of BC using the modified WS from the pulping of fir was superior to that using glucose as carbon source.
Birch (Betula pendula) Wood Discolouration during Drying. Effect of Environmental Factors and Wood Location in the Trunk
Authors: Luostarinen K. , Möttönen V. , Asikainen A. , Luostarinen J.
Published: September 2004

Birch wood discolours during artificial drying, which is a considerable problem for the use of birch as raw material in the mechanical wood industry. In this investigation sample boards ofBetula pendulawere sawn to the dimensions used as raw material for parquet billets. The variables studied were those that may affect wood discolouration: growing site, felling date, length of the storage period for logs and location of the wood in the trunk. Discoloration of birch wood was studied in conventional and vacuum drying processes. The wood layer of about 2–5 mm under the yellow surface of conventionally dried boards remained light-coloured, while the inner wood of the boards became discoloured. During vacuum drying, however, the inner wood of sample boards clearly became discoloured. The radial location of the wood in the trunk affected the colour of dried wood more than the longitudinal location did. To keep the colour of dry wood as light as possible, it may be best to fell birch in winter and store the wood for several weeks before conventional drying. On the other hand, the lightest coloured wood obtained during vacuum drying was from autumnfelled five weeks stored birches, which may indicate differences in the process of discoloration in these two drying methods.
Immuno Electron Microscopic Localization of Peroxidases in the Differentiating Xylem of Populus spp.
Authors: Kim Y.S. , Wi S.-G. , Grünwald C. , Schmitt U.
Published: September 2004

Peroxidases were localized in differentiating xylem cells of Populus spp. by means of immunogold labelling in combination with transmission electron microscopy (TEM). Polyclonal antibodies raised in rabbits against horseradish peroxidase were used for these experiments. Within the cytoplasm, TEM revealed a distinct labelling of the dictyosomes, indicating that these organelles are involved in the transport of peroxidases to the plasma membrane. During the formation of primary and secondary walls, cell corner regions became distinctly labelled, the developing secondary wall layers to a much lesser degree. Significant differences in the immunogold labelling between the intercorner middle lamella and the secondary cell wall layers were not observed. According to the immunogold labelling, peroxidases are incorporated into the secondary wall more or less simultaneously with deposition of polysaccharides. Correlations between peroxidase incorporation and lignification are discussed.
Study of Lewis Acid-Base Properties of Wood by Contact Angle Analysis
Authors: Wålinder M. E. P.
Published: September 2004

In the present work, an attempt is made to study the Lewis acid-base properties of wood by contact angle analysis. Using contact angle data for extracted, non-extracted, fresh and aged pine wood veneer samples, the Lewis acid-base contribution to the work of adhesion (W

a
AB
) and the Lewis acid-base components of the surface free energy of the wood samples were determined by basic wetting theory, and by the so-called van Oss-Chaudhury-Good (vOCG) model. Results show, on the one hand, that W

a
AB
between water and the non-extracted wood decreases with increasing aging time. This indicates that extractives migrate from the interior of wood to its exterior surface during the aging, creating a hydrophobic wood surface. On the other hand, W

a
AB
between the non-extracted wood and ethylene glycol tends to increase with longer aging times. No such trends are observed for extracted samples. If water is considered to be predominantly Lewis acidic, and ethylene glycol predominantly Lewis basic, the changes in W

a
AB
with longer aging times, indicate that the acidity and the basicity of non-extracted wood in these cases increases and decreases, respectively. This is presumably due to the presence of the extractives, and to reorientation of functional groups and oxidation at the wood/extractives-air interface. The acid-base characterization by the vOCG model also indicates that the acidity and the basicity of the non-extracted wood increases and decreases, respectively, with increasing aging time. However, there seems to be a similar trend even for extracted wood, presumably due to reorientation of functional groups at the wood-air interface. In the vOCG model, considerably higher base/acid ratios are obtained when using probe liquid parameters according to van Oss compared to those obtained by using liquid parameters according to Della Volpe and Siboni.
Lipophilic Extractives of the Inner and Outer Barks of Eucalyptus globulus
Authors: Freire C. S. R. , Silvestre A. J. D. , Neto C. Pascoal , Cavaleiro J.A.S.
Published: September 2004

The chemical compositions of the dichloromethane extracts of inner and outer barks of E. globulus were studied by gas chromatography-mass spectrometry. The two fractions show very different chemical compositions: triterpenic acids, such as betulinic, ursolic and oleanolic acids, were the major components of the outer bark extract, whereas β-sitosterol and β-amirin along with palmitic, linoleic and oleic acids predominate in the inner bark extract. Several α-and β-hydroxy fatty acids, recently reported for the first time as E. globulus wood components, were also identified in the outer and inner barks. In the outer bark extract, minor amounts of ferulic acid esters, also previously reported to occur in E. globulus wood were identified. In general, the inner bark lipophilic extractives resemble more closely that of E. globulus wood.
Thick-Target PIXE Analysis of Trace Elements in Wood Incoming to a Pulp Mill
Authors: Saarela K.-E. , Harju L. , Lill J.-O. , Rajander J. , Lindroos A. , Heselius S.-J. , Saari K.
Published: September 2004

Trunk-wood samples of wood raw material incoming to a pulp mill were analysed by thick-target particle induced X-ray emission (PIXE). The tree species studied were pine and spruce from Finland, birch from Finland and Poland and eucalyptus from Uruguay. The wood samples were dry ashed to 550 °C prior to the analysis in order to increase the sensitivity of the method. The method was calibrated and validated using some wood based certified reference materials. The elements determined with the method were P, S, K, Ca, Ti, Mn, Fe, Ni, Cu, Zn, Pb, Sr, Rb, Ba and F. The concentrations of the main elements P, S, K, Ca and Mn exceeded 50 ppm in most wood samples. The concentrations of heavy metal ions like Cu, Ni and Pb in the samples studied were below or close to 1 ppm. The ash content of birch, pine and spruce wood were in the range 0.2–0.4% and that of eucalyptus ca 0.5%.
Formation of Aliphatic Carboxylic Acids during Soda-AQ Pulping of Kenaf Bark
Authors: Feng Z. , Alén R. , Niemelä K.
Published: September 2004

The formation of aliphatic carboxylic acids during soda-AQ pulping of kenaf bark was studied. In addition to formic and acetic acids, a variety of hydroxy monocarboxylic and dicarboxylic acids were monitored. The results showed that the formation of hydroxy acids and formic acid significantly depend, in contrast to acetic acid, on the cooking conditions employed. Detailed gas chromatographic studies revealed that the most abundant hydroxy carboxylic acids were glucoisosaccharinic, lactic, glycolic, 3-deoxypentonic, 2-hydroxybutanoic, xyloisosaccharinic, 3,4-dideoxypentonic, 2-hydroxyglutaric, and glucoisosaccharinaric acids. The total amount of aliphatic carboxylic acids corresponded to 12–16% of o.d. kenaf bark.
Comparing Mechanical Properties of Normal and Compression Wood in Norway Spruce: The Role of Lignin in Compression Parallel to the Grain
Authors: Gindl W.
Published: September 2004

Cell-wall lignin content and composition, as well as microfibril angle of normal and compression wood samples were determined prior to mechanical testing in compression parallel to the grain. No effect of increased lignin content on the Young's modulus in compression wood was discernible because of the dominating influence of microfibril angle. In contrast, compressive strength of compression wood was not negatively affected by the high microfibril angle. It is proposed that the observed high lignification in compression wood increases the resistance of the cell walls to compression failure. An increased percentage of p-hydroxyphenylpropane units observed in compression wood lignin may also contribute to the comparably high compressive strength of compression wood.
Oxidative Ammonolysis of Technical Lignins. Part 3. Effect of Temperature on the Reaction Rate
Authors: Capanema E. A. , Balakshin M. Y. , Chen C.-L. , Gratzl J. S. , Kirkman A. G.
Published: September 2004

The effect of the reaction temperature on the kinetics and the reaction mechanism of oxidative ammonolysis of Repap organosolv lignin have been studied. The reaction was conducted in 0.8 M Nh4oh solution under oxygen pressure of 12 bar and at three different temperatures, 70 °C, 100 °C and 130 °C. The resulting N-modified lignins were analyzed by elemental and methoxyl group. About 20–25% of maximum nitrogen content is incorporated into the lignin very fast, in 1–2 min of the reaction. The reaction kinetics then follows a pseudo-first order reaction law and consists of two phases. The activation energies for nitrogen incorporation and lignin solubilization are rather low, in the range of 33–34 kJ/mol. Linear correlation between nitrogen incorporated into the lignin and molecular oxygen uptake, oxygen incorporation, CO2 formation, O-demethylation and total carbon loss was analyzed at the different reaction temperatures. On the basis of kinetic data obtained so far, we have postulated that the reaction temperature affects the reaction rate, but not the reaction pathways. The reaction temperature also affects the ratios between different reaction pathways, though the effect is not very strong. The results obtained are discussed in the terms of competitive reactions of lignin oxidation followed by nitrogen incorporation and lignin deactivation involving nitrogen