Effects of N′-N-(1, 8-Naphthalyl) hydroxylamine (NHA-Na) and hydroxynaphthalimide (NHA-H) on boron leachability and biological degradation of wood

Although boron wood preservatives have many advantages, boron itself does not adequately protect wood in ground contact and exterior applications because its susceptibility to leaching. As a result of previous studies to limit or decrease boron leaching, several fixation systems have been developed. In this study, we evaluated the effects of N′-N-(1, 8-Naphthalyl) hydroxylamine (NHA-Na) and hydroxynaphthalimide (NHA-H) on boron leaching and decay and termite resistance via possible boron precipitation in wood after NHA treatments at varying concentrations. Results showed that treatment of wood blocks with disodium octaborate tetrahydrate (DOT), boric acid (BA), or calcium tetraborate (CaB) incorporation with 1.0% NHA-Na solutions in sequential processes appears to somewhat reduce the susceptibility of boron to leaching. Blocks treated sequentially with boron compounds and then 1.0% NHA-Na solutions showed about 30% less boron leaching compared to boron only treated blocks. In addition, the existence of boron and NHA-Na in wood together showed a synergistic effect against brown-rot fungus, Fomitopsis palustris. We conclude that the relationship between boron and NHA-Na concentration in wood as regards precipitation possibilities appears to be predictive for reducing boron leachability.ZusammenfassungObwohl Schutzmittel auf Borbasis einige Vorteile aufweisen, schützt Bor das Holz nicht ausreichend bei Bodenkontakt und Außenverwendung, weil es leicht ausgewaschen wird. Aufgrund früherer Ergebnisse zum Begrenzen der Auslaugbarkeit von Bor wurden mehrere Fixiersysteme entwickelt. In dieser Arbeit wird der Einfluss von von N′-N-(1, 8-Naphthalyl)-Hydroxylamin (NHA-Na) und Hydroxynaphthalimid (NHA-H) auf die Auslaugbarkeit und die Termitenresistenz bewertet. Die Fixierung beruht auf den möglichen Ausfällen von Bor im Holz nach der NHA-Behandlung mit verschiedenen Konzentrationen. Die Ergebnisse zeigen, dass die Auslaugbarkeit von Bor reduziert werden kann durch aufeinanderfolgendes Behandeln der Holzklötzchen mit Zusatz von Dinatrium-Octaborat-Tetrahydrat (DOT), Borsäure (BA) oder Calciumtetraborat (CaB) in 1,0% NHA-Na-Lösung. Klötzchen, die zunächst mit Bor-Komponenten und danach mit 1,0% NHA-Na behandelt wurden, zeigten eine 30% geringere Auslaugbarkeit im Vergleich zu nur mit Bor behandelten Proben. Zusätzlich zeigte die gleichzeitige Anwesenheit von Bor und NHA-Na einen synergistischen Effekt gegen Braunfäule (Fomitopsis palustris).

[1]  S. Kartal,et al.  Development and application of colorimetric microassay for determining boron-containing compounds , 2002 .

[2]  S. Kartal,et al.  Fiberboards treated with N’-N-(1, 8-Naphthalyl) hydroxylamine (NHA-Na), borax, and boric acid , 2004 .

[3]  Yuji Imamura,et al.  Bioremediation of CCA-treated wood by brown-rot fungi Fomitopsis palustris, Coniophora puteana, and Laetiporus sulphureus , 2005, Journal of Wood Science.

[4]  F. Green,et al.  Production of Polygalacturonase and Increase of Longitudinal Gas Permeability in Southern Pine by Brown-Rot and White-Rot Fungi , 1999 .

[5]  S. Kartal,et al.  Effects of inorganic ions on leachability of wood preserving N'N-hydroxynapthalimide (NHA). , 2004 .

[6]  E. Gezer,et al.  Boron addition to non- or low-formaldehyde cross-linking reagents to enhance biological resistance and dimensional stability of wood , 1999, Holz als Roh- und Werkstoff.

[7]  Frederick Green,et al.  Pectin degradation during colonization of wood by brown-rot fungi , 2003 .

[8]  A. Peylo,et al.  The Problem of Reducing the Leachability of Boron by Water Repellents , 1995 .

[9]  M. Thévenon,et al.  Protein Borates as Non-Toxic, Long-Term, Wide-Spectrum, Ground-Contact Wood Preservatives , 1998 .

[10]  F. Green,et al.  Copper tolerance of brown-rot fungi: time course of oxalic acid production , 2003 .

[11]  P. Gérardin,et al.  Glycerol/Glyoxal: A New Boron Fixation System for Wood Preservation and Dimensional Stabilization , 2000 .

[12]  T. Yoshimura,et al.  Inhibition of termite damage by N`N-napthaloylhydroxyamine (NHA) : Reticulotermes flavipes (Kollar) vs. Coptotermes formosanus Shiraki , 2000 .

[13]  F. Green,et al.  Protection of southern pine from fungal decay and termite damage with N,N-naphthaloylhydroxylamine , 1997 .

[14]  E. Gezer,et al.  Enhancement of Biological and Physical Properties of Wood by Boric Acid-Vinyl Monomer Combination Treatment , 1998 .

[15]  T. Tokimatsu,et al.  A physiological role for oxalic acid biosynthesis in the wood-rotting basidiomycete Fomitopsis palustris , 2001, Proceedings of the National Academy of Sciences of the United States of America.