Chemical modification of Petersianthus macrocarpus (essia), to determine whether durability depends on bulking or hydroxyl substitution

Wood is a biodegradable material. Decay resistance of wood is improved when the wood is chemically modified. The decayresistance of a chemically modified wood is improved as the modification stabilizes the cell wall polymers against enzyme attackdue to the blocking of accessible hydroxyl groups of the cell wall polymers which reduces the amount of water for hydrolysis. Theimproved durability of the modified wood as a result of reducing the amount of water molecules into the cell wall for hydrolysiswill depend on either bulking or percentage hydroxyl substitution (%OH). Petersianthus macrocarpus (essia), a tropical hardwoodspecies was chemically modified with acetic anhydride (AA) and pentanoic anhydride (PA) in dry pyridine to improve its decayresistance. Graveyard test was used to analyze the effect of the modification on the decay resistance of the wood in twelve weeksin-ground contact. Percentage weight loss and visual decay grades were used to evaluate whether the decay resistance dependson weight percentage gain or percentage hydroxyl substitution. The decay resistance of the modified samples were found to bedependent on bulking.

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Mode of action of brown rot decay resistance in modified wood: a review

Holzforschung ◽

10.1515/hf-2013-0057 ◽

2014 ◽

Vol 68 (2) ◽

pp. 239-246 ◽

Cited By ~ 66

Author(s):

Rebecka Ringman ◽

Annica Pilgård ◽

Christian Brischke ◽

Klaus Richter

Keyword(s):

Cell Wall ◽

Mode Of Action ◽

Wood Decay ◽

Brown Rot ◽

Decay Resistance ◽

Hydroxyl Groups ◽

Decay Fungi ◽

Brown Rot Decay ◽

Thermally Modified Wood ◽

Modified Wood

Abstract Chemically or physically modified wood materials have enhanced resistance to wood decay fungi. In contrast to treatments with traditional wood preservatives, where the resistance is caused mainly by the toxicity of the chemicals added, little is known about the mode of action of nontoxic wood modification methods. This study reviews established theories related to resistance in acetylated, furfurylated, dimethylol dihydroxyethyleneurea-treated, and thermally modified wood. The main conclusion is that only one theory provides a consistent explanation for the initial inhibition of brown rot degradation in modified wood, that is, moisture exclusion via the reduction of cell wall voids. Other proposed mechanisms, such as enzyme nonrecognition, micropore blocking, and reducing the number of free hydroxyl groups, may reduce the degradation rate when cell wall water uptake is no longer impeded.

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Decay resistance of anhydride-modified Corsican pine sapwood exposed to the brown rot fungus Coniophora puteana

Holzforschung ◽

10.1515/hf.2006.105 ◽

2006 ◽

Vol 60 (6) ◽

pp. 625-629 ◽

Cited By ~ 30

Author(s):

Callum A.S. Hill ◽

Michael D. Hale ◽

Graham A. Ormondroyd ◽

Jin H. Kwon ◽

Simon C. Forster

Keyword(s):

Brown Rot ◽

Pinus Nigra ◽

Decay Resistance ◽

Exposure Test ◽

Weight Percentage ◽

Coniophora Puteana ◽

Chemically Modified ◽

Brown Rot Fungus ◽

The Relationship ◽

Modified Wood

Abstract Corsican pine (Pinus nigra) sapwood was chemically modified with acetic or hexanoic anhydride to a variety of weight gains. The modified wood was exposed to the brown rot fungus Coniophora puteana, and the relationship between weight loss due to decay and weight percentage gain, or degree of hydroxyl substitution, was determined in a 16-week exposure test. The effect of exposure time and the strain of C. puteana upon the decay protection threshold of acetylated Corsican pine was also examined.

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Growth behavior of wood-destroying fungi in chemically modified wood: wood degradation and translocation of nitrogen compounds

Holzforschung ◽

10.1515/hf-2020-0252 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Lukas Emmerich ◽

Maja Bleckmann ◽

Sarah Strohbusch ◽

Christian Brischke ◽

Susanne Bollmus ◽

...

Keyword(s):

Protective Action ◽

Treated Wood ◽

Untreated Wood ◽

Brown Rot ◽

Decay Resistance ◽

White Rot ◽

Decay Fungi ◽

Chemically Modified ◽

Decay Tests ◽

Modified Wood

Abstract Chemical wood modification has been used to modify wood and improve its decay resistance. However, the mode of protective action is still not fully understood. Occasionally, outdoor products made from chemically modified timber (CMT) show internal decay while their outer shell remains intact. Hence, it was hypothesized that wood decay fungi may grow through CMT without losing their capability to degrade non-modified wood. This study aimed at developing a laboratory test set-up to investigate (1) whether decay fungi grow through CMT and (2) retain their ability to degrade non-modified wood. Acetylated and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) treated wood were used in decay tests with modified ‘mantle specimens’ and untreated ‘core dowels’. It became evident that white rot (Trametes versicolor), brown rot (Coniophora puteana) and soft rot fungi can grow through CMT without losing their ability to degrade untreated wood. Consequently, full volume impregnation of wood with the modifying agent is required to achieve complete protection of wooden products. In decay tests with DMDHEU treated specimens, significant amounts of apparently non-fixated DMDHEU were translocated from modified mantle specimens to untreated wood cores. A diffusion-driven transport of nitrogen and DMDHEU seemed to be responsible for mass translocation during decay testing.

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Changes in the Physico-chemical Properties of Peach Fruit Pectin during On-tree Ripening and Storage

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.118.3.343 ◽

1993 ◽

Vol 118 (3) ◽

pp. 343-349 ◽

Cited By ~ 32

Author(s):

M.L. Fishman ◽

B. Levaj ◽

D. Gillespie ◽

R. Scorza

Keyword(s):

Molecular Weight ◽

Cell Wall ◽

Intrinsic Viscosity ◽

Cell Walls ◽

Prunus Persica ◽

Chemical Properties ◽

Radius Of Gyration ◽

Weight Percentage ◽

Pectin Content ◽

Cell Wall Polymers

Radius of gyration (size), intrinsic viscosity, molecular weight, percentage of galacturonate, and percentage of neutral sugars were measured for chelate-soluble (CSP) and alkaline-soluble (ASP) pectins extracted from the cell walls of melting flesh (MF) and nonmelting flesh (NMF) peach [Prunus persica (L.) Batsch]. Weight percentage of cell walls, pectin content, and firmness were measured also. Peaches were extracted at 20, 21, and 22 weeks after flowering (WAF) and after various lengths of shelf storage at 25 ± 2C for the peaches picked at 21 WAF. Weight percentage of cell walls and firmness decreased markedly between the 21st and 22nd WAF; and between the 3rd and 6th day of storage for MF peaches as compared to NMF peaches. During these same periods, there were marked drops in the pectin content and the uronide content for MF as compared to NMF peaches. Size and intrinsic viscosity dropped markedly for CSP of MF peaches in comparison with NMF peaches during these same periods, whereas the molecular weight of CSP and ASP increased in MF peaches over that measured for NMF peaches. These results suggested that α -D-galacturonase (E.C. 3.2.1.15) was involved in softening only in the latter stages of ripening MF peaches. Further, cell wall polymers containing long thin pectin aggregates were destroyed, whereas cell wall polymers containing short thick pectin aggregates remained.

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An investigation of cell wall micropore blocking as a possible mechanism for the decay resistance of anhydride modified wood

International Biodeterioration & Biodegradation ◽

10.1016/j.ibiod.2004.07.003 ◽

2005 ◽

Vol 55 (1) ◽

pp. 69-76 ◽

Cited By ~ 87

Author(s):

C.A.S. Hill ◽

S.C. Forster ◽

M.R.M. Farahani ◽

M.D.C. Hale ◽

G.A. Ormondroyd ◽

...

Keyword(s):

Cell Wall ◽

Decay Resistance ◽

Modified Wood

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Chemical modification of pine wood with propionic anhydride: Effect on decay resistance and sorption of water vapour

BioResources ◽

10.15376/biores.1.1.67-74 ◽

2006 ◽

Vol 1 (1) ◽

pp. 67-74

Keyword(s):

Weight Gain ◽

Water Vapour ◽

Scots Pine ◽

Linear Chain ◽

Decay Resistance ◽

Complete Protection ◽

Water Vapour Sorption ◽

Chemically Modified ◽

Propionic Anhydride ◽

Modified Wood

The purpose of this paper is to show the effects of level of substitution with a linear chain anhydride (propionic anhydride) on decay resistance and on water vapour sorption of modified Scots pine sapwood. The work described herein has demonstrated that chemically modified Scots pine sapwood with propionic anhydride afforded substantial bioprotection against Coniophora puteana . It required a weight gain of approximately 17% following reaction to ensure complete protection. The sorption of water vapour of propionic anhydride modified wood was greatly reduced.

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The effect of substituent distribution on the decay resistance of chemically modified wood

International Biodeterioration & Biodegradation ◽

10.1016/j.ibiod.2005.10.009 ◽

2006 ◽

Vol 57 (1) ◽

pp. 57-62 ◽

Cited By ~ 9

Author(s):

Naoto Habu ◽

Yoko Nagasawa ◽

Masahiro Samejima ◽

Tomoko M. Nakanishi

Keyword(s):

Decay Resistance ◽

Substituent Distribution ◽

Chemically Modified ◽

Modified Wood

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Accessibility of hydroxyl groups in anhydride modified wood as measured by deuterium exchange and saponification

Holzforschung ◽

10.1515/hf-2017-0059 ◽

2017 ◽

Vol 72 (1) ◽

pp. 17-23 ◽

Cited By ~ 18

Author(s):

Greeley Beck ◽

Sarah Strohbusch ◽

Erik Larnøy ◽

Holger Militz ◽

Callum Hill

Keyword(s):

Cell Wall ◽

Steric Hindrance ◽

High Performance ◽

Radiata Pine ◽

Deuterium Exchange ◽

Hydroxyl Groups ◽

Oh Groups ◽

Weight Percentage ◽

Water Accessibility ◽

Responsible Mechanism

AbstractAcetylated wood (WAc) shows improved properties largely due to the reduced amount of water in its cell wall, but the exact mechanism of water reduction remains unclear. Acetylation reduces hydroxyl (OH) content by acetyl (Ac) substitution but may also limit water access to unmodified OH groups by steric hindrance. In the present work, the accessibility of OH groups in acetylated or propionylated Radiata pine (Pinus radiataD. Don) wood (WAcand WPr) was investigated by deuterium exchange, saponification in sodium hydroxide followed by high-performance liquid chromatography (HPLC) analysis and weight percentage gain determination of the modified samples. Acetylation reduced OH accessibility (OHA) to a greater extent than would be predicted, if OH substitution were the only responsible mechanism for accessibility reduction. The combination of deuterium exchange and saponification results provides strong evidence that steric hindrance plays a key role in reduction of water accessibility to unmodified OH groups in WAc. The supramolecular architecture of WPrsamples seems to be modified by the propionylation reaction, which leads to increased OHAat low levels of substitution. This suggests that molecular restructuring within the cell wall exposes new OH groups after propionylation. At higher levels of substitution, however, the WPrexhibited less OHAthan expected indicating steric hindrance from the propionyl groups.

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Characterisation of Moisture in Scots Pine (Pinus sylvestris L.) Sapwood Modified with Maleic Anhydride and Sodium Hypophosphite

Forests ◽

10.3390/f12101333 ◽

2021 ◽

Vol 12 (10) ◽

pp. 1333

Author(s):

Injeong Kim ◽

Emil Engelund Thybring ◽

Olov Karlsson ◽

Dennis Jones ◽

George I. Mantanis ◽

...

Keyword(s):

Cell Wall ◽

Maleic Anhydride ◽

Scots Pine ◽

Cell Walls ◽

Sodium Hypophosphite ◽

Hydroxyl Groups ◽

Capillary Water ◽

Saturated State ◽

Water Saturated ◽

Modified Wood

In this study, the wood–water interactions in Scots pine sapwood modified with maleic anhydride (MA) and sodium hypophosphite (SHP) was studied in the water-saturated state. The water in wood was studied with low field nuclear magnetic resonance (LFNMR) and the hydrophilicity of cell walls was studied by infrared spectroscopy after deuteration using liquid D2O. The results of LFNMR showed that the spin–spin relaxation (T2) time of cell wall water decreased by modification, while T2 of capillary water increased. Furthermore, the moisture content and the amount of water in cell walls of modified wood were lower than for unmodified samples at the water-saturated state. Although the amount of accessible hydroxyl groups in modified wood did not show any significant difference compared with unmodified wood, the increase in T2 of capillary water indicates a decreased affinity of the wood cell wall to water. However, for the cell wall water, the physical confinement within the cell walls seemed to overrule the weaker wood–water interactions.

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Cell Wall Bulking by Maleic Anhydride for Wood Durability Improvement

Forests ◽

10.3390/f11040367 ◽

2020 ◽

Vol 11 (4) ◽

pp. 367 ◽

Cited By ~ 3

Author(s):

Mingming He ◽

Dandan Xu ◽

Changgui Li ◽

Yuzhen Ma ◽

Xiaohan Dai ◽

...

Keyword(s):

Cell Wall ◽

Maleic Anhydride ◽

Wood Cell Wall ◽

Brown Rot ◽

Decay Resistance ◽

White Rot ◽

White Rot Fungus ◽

Hydroxyl Group ◽

Hydroxyl Groups ◽

Decay Fungi

Wood is susceptible to swelling deformation and decay fungi due to moisture adsorption that originates from the dynamic nanopores of the cell wall and the abundant hydroxyl groups in wood components. This study employed as a modifier maleic anhydride (MAn), with the help of acetone as solvent, to diffuse into the wood cell wall, bulk nanopores, and further chemically bond to the hydroxyl groups of wood components, reducing the numbers of free hydroxyl groups and weakening the diffusion of water molecules into the wood cell wall. The derived MAn-bulked wood, compared to the control wood, presented a reduction in water absorptivity (RWA) of ~23% as well as an anti-swelling efficiency (ASE) of ~39% after immersion in water for 228 h, and showed an improvement in decay resistance of 81.42% against white-rot fungus and 69.79% against brown-rot fungus, respectively. The method of combined cell wall bulking and hydroxyl group bonding could effectively improve the dimensional stability and decay resistance with lower doses of modifier, providing a new strategy for wood durability improvement.

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