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US Forest Service Research & Development
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  • US Forest Service Research & Development
  • 1400 Independence Ave., SW
  • Washington, D.C. 20250-0003
  • 800-832-1355
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Research Highlights

Individual Highlight

Elucidating Covalent Bond Formation and Cleavage in Wood

The figure shows two-dimensional NMR spectra of control (unreacted) loblolly pine and loblolly pine that has been reacted with a model compound of pMDI adhesive. The labels A, B, and C (and α, β, γ positions) relate to the chemical structures at the bottom of the figure. The contours labeled with a subscript r show reacted wood cell wall polymers. The reactivity of the lignin sidechains clearly dominates over all other wood cell wall polymers. Forest ServiceSnapshot : Working with a group at the University of Wisconsin-Madison, Department of Biochemistry, FPL researchers have discovered mechanistic details behind some long-standing theories of wood adhesion and brown-rot fungal decay. Firstly, solution-state nuclear magnetic resonance spectroscopy

Principal Investigators(s) :
Daniel Yelle 
Research Location : FPL and the University of Wisconsin-Madison
Research Station : Forest Products Laboratory (FPL)
Year : 2010
Highlight ID : 173

Summary

Understanding the chemical changes of lignocellulosic polymers subjected to different chemical and biological processes is complex. The common practices of isolating cell wall components for individual analyses is time consuming and can alter the native structure of lignocellulosics in wood. Working with a group at the University of Wisconsin-Madison, Department of Biochemistry, FPL researchers have discovered mechanistic details behind some long-standing theories of wood adhesion and brown-rot fungal decay. Firstly, solution-state nuclear magnetic resonance spectroscopy (NMR) of dissolved wood cell walls has been applied to delineate reactions between pMDI (polymeric methylene diphenyl diisocyanate) adhesives and wood, showing that covalent bonds between wood and pMDI are non-contributors for pMDI-wood bond durability. Secondly, NMR of dissolved brown-rotted wood revealed marked bond cleavage of βO-4-linked lignin sidechains, thus significantly altering the original lignin polymer in wood. Other applications of this technology will include investigating how coatings and finishes interact with wood, how to describe changes in the chemistry of wood for improved durability, how the structure of lignocellulosics change after genetic modification of trees, and how other decay fungi degrade lignocellulosics in wood.

Forest Service Partners

External Partners

 
  • University of Wisconsin- Department of Biochemistry

Research Topics

Priority Areas

  • Resource Management and Use
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