Effect of chemical modification and heat treatment on biological durability and dimensional stability of Pinus roxburghii Sarg.

Background: Depleting supplies of wood species with inherent natural durability has resulted in the focus being shifted to non-durable plantation grown and imported timber. Despite its abundant availability and better treatability, the use of Pinus roxburghii is limited to packing cases, crates, shutters, door and window frame, carpentry and joinery items due to its nondurable nature. Hence, to promote use of such timber for applications such as decking, cladding and facade elements chemical modification with a combination of citric acid and sodium hypophosphite, and heat treatment were explored to improve its service life. Methods: Chemical modification was performed using a water solution of citric acid (6.9%) and sodium hypophosphite (6.5%) followed by curing at 140°C for 8 hrs. Dimensional stability was determined by estimating the volumetric swelling coefficient and anti-swelling efficiency (ASE) of treated and control samples. Durability against fungus and termites was evaluated using a soil block bioassay and termite mound test as per standard methods. Results: Both chemical modification and heat treatment of P. roxburghii resulted in enhanced dimensional stability and biological durability compared to the untreated controls. Chemical modification and heat treatment resulted in 23.05% and 18.37% volumetric ASE, respectively. Results showed that a highly perishable species became significantly more durable after chemical modification, exhibiting 5–6 times less mass loss by termites in comparison to the controls. Wood samples modified with citric acid showed excellent resistance to both white and brown rot fungi and exhibited 14-15 times less reduction in mass compared with untreated samples. Conclusions: Citric acid chemical modification is an environment friendly process that improved the dimensional stability as well as resistance against biodegradation. These studies may provide valuable inputs to establish this mode of chemical modification as a cost-effective alternative to other chemicals for wood preservation. The concentrations of the chemicals and temperature for fixation may be varied to establish an optimum combination for best output.

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Chemical, physico-mechanical properties and biological durability of rubberwood particleboards after post heat-treatment in palm oil

Holzforschung ◽

10.1515/hf-2017-0086 ◽

2018 ◽

Vol 72 (2) ◽

pp. 159-167 ◽

Cited By ~ 6

Author(s):

Seng Hua Lee ◽

Zaidon Ashaari ◽

Wei Chen Lum ◽

Aik Fei Ang ◽

Juliana Abdul Halip ◽

...

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Palm Oil ◽

Dimensional Stability ◽

Urea Formaldehyde ◽

Chemical Properties ◽

Water Repellency ◽

Post Heat Treatment ◽

Termite Resistance ◽

Biological Durability

AbstractThe chemical properties, dimensional stability, mechanical strength and termite resistance of urea formaldehyde (UF) bond rubberwood (RW) particleboard (PB) were assessed after a two-step oil heat treatment (OHT). The PB was immersed in palm oil before heating to 180, 200, and 220°C in a laboratory oven for 2 h. Anti-swelling efficiency (ASE) and water repellency efficiency (WRE) as well as bending (MOE, MOR) and internal bonding strength (IB) were determined. Resistance against a subterranean termite,Coptotermes curvignathusHolmgren, was tested. The degradation of hemicelluloses and cellulose, that are mainly responsible for wood wetting processes, was confirmed by Fourier transform infrared (FTIR) spectra. Formation of an elevated cross-linking density in lignin also contributed to the dimensional stability, where 93.6% ASE and 46.3% WRE were achieved in the samples treated at 220°C. Mechanical properties of treated samples were inferior to the control samples due to hemicelluloses degradation and breakage of the UF bonding network. A significant improvement in termite resistance has been found in the treated samples.

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DECAY RESISTANCE, DIMENSIONAL STABILITY AND MECHANICAL STRENGTH OF POPLAR WOOD MODIFIED WITH PLANT-DERIVED COMPOUNDS

Wood Research ◽

10.37763/wr.1336-4561/66.4.556568 ◽

2021 ◽

Vol 66 (4) ◽

pp. 556-568

Author(s):

JIAPENG WANG ◽

ZHENJU BI ◽

ZHANGJING CHEN ◽

LI YAN ◽

YAFANG LEI

Keyword(s):

Mechanical Properties ◽

Citric Acid ◽

Dimensional Stability ◽

Color Change ◽

White Rot Fungi ◽

Brown Rot ◽

Decay Resistance ◽

White Rot ◽

Modulus Of Rupture ◽

Weight Percentage

The cinnamaldehyde, salicylic acid, stearolic acid and citric acid were plant-derived organic compounds that can be activated to fungi, that could degrade the wood in long term. The compounds with concentrations of 3%, 5% and 7% assisted by different dispersants were impregnated into poplar (Populus nigra L.) specimens by the vacuum-pressure method. After that, weight percentage gain (WPG), decay resistance against white-rot fungi (Trametes versicolor) and brown-rot fungi (Gloeophyllum trabeum), color change, dimensional stability and mechanical properties including modulus of elasticity (MOE) and modulus of rupture (MOR) were measured. The results indicated that cinnamaldehyde impregnated poplar showed antifungi activity against both G. trabeumand T. versicolor, and citric acid impregnated poplar showed antifungi activity against G. trabeum. The color of poplar specimens before and after impregnated cinnamaldehyde and citric acid had a little change, dimensional stability had been improved and mechanical properties especially for MOR increased significantly.

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Dimensional stabilisation of Scots pine (Pinus sylvestris L.) sapwood by reaction with maleic anhydride and sodium hypophosphite

European Journal of Wood and Wood Products ◽

10.1007/s00107-020-01650-6 ◽

2021 ◽

Author(s):

Injeong Kim ◽

Olov Karlsson ◽

Dennis Jones ◽

George Mantanis ◽

Dick Sandberg

Keyword(s):

Maleic Anhydride ◽

Chemical Modification ◽

Scots Pine ◽

Dimensional Stability ◽

Hydrolytic Stability ◽

Treatment Temperature ◽

Sodium Hypophosphite ◽

Cross Linking ◽

High Concentration ◽

Weight Percentage

AbstractWood has the ability to absorb and desorb moisture, which can affect its dimensional size when in use. Limiting this can provide products with greater shape stability and less stresses on external coatings. One method that has been investigated for achieving this has been through chemical modification. In this work, the dimensional stabilisation imparted to Scots pine sapwood by chemical modification with maleic anhydride (MA) combined with sodium hypophosphite (SHP) was investigated. The influence of concentration of MA, treatment temperature and treatment period on weight percent gain (WPG) and bulking coefficient (BC) during treatment with MA and SHP of wood was studied. Furthermore, dimensional stability was determined by the water soak/oven dry method (wet-dry cycle) through five cycles in order to determine the hydrolytic stability of the ester bond and any potential cross-linking reactions. Wood blocks (20 × 20 × 10 mm) modified with MA combined with SHP exhibited lower weight loss following water soaking than unmodified blocks or MA-treated blocks. Wood blocks modified with MA and SHP showed the best anti-swelling efficiency and minimum wet-volume (water-saturated). However, as the concentration of SHP increased, dimensional stability was diminished without any increase in weight percentage gain after water soaking. When combined with FTIR results, it appeared that the modification with MA and SHP seemed to form cross-linking between wood constituents, though high concentration of SHP did not seem to result in additional cross-linking.

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Effect of the Heat Treatment on the Dimensional Stability of Si Electrodes with PVDF Binder

Electrochimica Acta ◽

10.1016/j.electacta.2016.05.183 ◽

2016 ◽

Vol 211 ◽

pp. 356-363 ◽

Cited By ~ 9

Author(s):

Seung Sik Hwang ◽

Myungbeom Sohn ◽

Hyeong-Il Park ◽

Jae-Man Choi ◽

Chang Gi Cho ◽

...

Keyword(s):

Heat Treatment ◽

Dimensional Stability

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The influence of heat treatment on the properties of shape memory fibers. II. Tensile properties, dimensional stability, recovery force relaxation, and thermomechanical cyclic properties

Journal of Applied Polymer Science ◽

10.1002/app.29165 ◽

2009 ◽

Vol 111 (3) ◽

pp. 1156-1164 ◽

Cited By ~ 17

Author(s):

Qinghao Meng ◽

Jinlian Hu ◽

Lap Yan Yeung ◽

Yang Hu

Keyword(s):

Heat Treatment ◽

Shape Memory ◽

Tensile Properties ◽

Dimensional Stability ◽

Force Relaxation ◽

Shape Memory Fibers

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Effect of Heat Treatment on Sorption Properties and Dimensional Stability of Wood

Materials Science ◽

10.5755/j01.ms.19.3.5239 ◽

2013 ◽

Vol 19 (3) ◽

Author(s):

Povilas NAVICKAS ◽

Darius ALBREKTAS

Keyword(s):

Heat Treatment ◽

Dimensional Stability ◽

Sorption Properties

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Dimensional Stability of Poplar Wood after Densification Combined with Heat Treatment

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.152-154.112 ◽

2012 ◽

Vol 152-154 ◽

pp. 112-116 ◽

Cited By ~ 2

Author(s):

Jia Bin Cai ◽

Tao Ding ◽

Liu Yang

Keyword(s):

Heat Treatment ◽

Dimensional Stability ◽

Hybrid Poplar ◽

Treatment Temperature ◽

Thermal Modification ◽

Holding Time ◽

Poplar Wood ◽

Compression Set ◽

Densification Temperature

Hybrid poplar boards were subjected to thermo-mechanical densification combined with heat treatment. Hydroscopicity and hygroscopicity of the treated samples were measured. The results showed that dimensional stability of the samples was influenced by compression set significantly. The higher the compression set, the greater the swelling of the samples. On the contrary, the influence of densification temperature and duration was not significant. Thermal modification significantly reduced hydroscopicity and hygroscopicity of the samples. Both higher treatment temperature and longer holding time resulted in better dimensional stability.

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Uphill Quenching of Aluminum Alloys

Encyclopedia of Aluminum and Its Alloys ◽

10.1201/9781351045636-140000235 ◽

2019 ◽

Author(s):

Wellington da Silva Mattos ◽

George Edward Totten ◽

Lauralice de Campos Franceschini Canale

Keyword(s):

Mechanical Properties ◽

Heat Treatment ◽

Residual Stress ◽

Aluminum Alloys ◽

Temperature Gradient ◽

Dimensional Stability ◽

Steam Chamber ◽

Conventional Heat Treatment ◽

Quenching Process ◽

Uphill Quenching

This article describes the concept of uphill quenching process applied in the heat treatment of aluminum alloys. Uphill quenching is interesting since residual stress reductions of up to 80% has been reported. In addition, substantial improvements in dimensional stability have been achieved for several types of aluminum parts. Often, uphill quenching is applied after quenching and before aging during the heat treatment of aluminum alloys. The uphill quenching process consists of the immersion of the part in a cryogenic environment, and after homogenization of the temperature, the part is transferred to the hot steam chamber to obtain a temperature gradient that will maintain the mechanical properties gained with this process. The results obtained are lower residual stress and better dimensional stability. The aim of this article is to provide a review of this process and to compare it with conventional heat treatment.

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Wood Preservation Based on In situ Polymerization of Bioactive Monomers. Part 2. Fungal Resistance and Thermal Properties of Treated Wood

Holzforschung ◽

10.1515/hf.2001.061 ◽

2001 ◽

Vol 55 (4) ◽

pp. 365-372 ◽

Cited By ~ 7

Author(s):

Rebecca E. Ibach ◽

Roger M. Rowell

Keyword(s):

In Situ Polymerization ◽

Treated Wood ◽

Brown Rot ◽

Fungal Resistance ◽

Wood Preservation ◽

Maximum Temperature ◽

Treatment Level ◽

Gloeophyllum Trabeum ◽

Crosslinker Concentration

Summary This paper is the second in a two-part series on in situ polymerization of bioactive monomers as an alternative to conventional preservative treatments. In this part of the study, bioactive monomers were evaluated for their ability to provide resistance to decay and protection against fire. Five bioactive monomers were synthesized: (1) pentachlorophenolyl acrylate (PCPA), (2) tributyltin acrylate (TBTA), (3) 8-hydroxyquinolyl acrylate (HQA), (4) 5,7-dibromo-8-hydroxyquinolyl acrylate (DBHQA), and (5) diethyl-N1N-bis (acryloxyethyl) aminomethyl phosphonate (Fyrol 6 acrylate, F6A). Southern pine sapwood samples were treated with acrylate solutions at different retention levels and with various amounts of crosslinker (trimethylolpropane trimethacrylate, TMPTM), then polymerized in situ. Methyl methacrylate (MMA) was used as the control. Biological resistance to the brown-rot fungus Gloeophyllum trabeum was determined on acetone-leached and unleached samples. PCPA showed some biological efficacy in the absence of crosslinker, but otherwise provided no more protection than did MMA alone. TBTA was biologically effective at all retention levels except with crosslinker concentration ≥10 %. HQA was biologically effective at ≥ 2% retention. F6A was not biologically effective, although unleached wood treated with 10% F6A and 5% or no crosslinker showed some resistance to decay. The 5% DBHQA plus 5% crosslinker treatment was biologically effective in both leached and unleached wood. The effects of the highest treatment level of each monomer, after polymerization, were also evaluated by thermogravimetric analysis. All treatments provided some resistance to fire. The best treatment was 10 % F6A, which resulted in the lowest mass loss (67.0 %) and the lowest maximum temperature of pyrolysis (308.5 °C).

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