Center research themes are selected and defined by the WBC Center Industry Advisory Board. The following list was established by the Board in July 2009 and will be updated periodically. Click on any of the themes listed below for a detailed description of each:

1. Emission Characterization

   An improved understanding of wood-related emissions is required, including emissions from native wood and from wood in any technologically significant state of processing. General research areas and topics include, but are not limited to:

   1. Native wood
      • Species effects.
      • Primary processing effects (machining and drying).
   2. Modified wood
      • Influence of chemical manipulations.
      • Influence of physical manipulations (e.g. mechanical, hygro-thermo-mechanical).
   3. Wood-based composites
      • Chemical characterization of decomposition by-products; understanding the fate of chemicals such as (but not limited to) aldehydes, ureas, and phenols; decomposition conditions mimicking environments of: composite manufacture, interior & exterior construction, and of marine, fire, and land-fill exposure.
      • Generation and migration of volatile organic compounds during production, covering a range of process conditions to determine control points and how these relate to composite performance.
      • Implications of composite/binder interactions.
      • Chemical and mechanical effects of composite-system design.

2. Green Building Systems

   Successful research proposals will address issues relating to improved sustainability of wood-based composites. The term sustainability relates to the ability of certain materials and/or practices to be maintained without depletion. Proposals must be directed towards improving our fundamental understanding of the topic, and must not be targeted towards the commercial development of specific materials, products or practices. Proposals may address:

   • Failure-modes and mechanisms of existing wood-based composites used in building systems, including those related to long-term weather exposure and the response of wood-based composites to sustained loads and cyclic environmental conditions.
   • Theoretical identification of ideal properties for sustainable wood-based composites of the future.
   • Methods for predicting the performance-life of wood-based composites under a given set of conditions.
   • Development of objective rating systems and measures for the sustainability of wood-based composites.
   • Forecasting of environmental change and the associated effects on the life-span of wood-based composites.
   • Demographic trends and evolving expectations for the functional requirements of homes and commercial buildings and the implications that these changes might have for the sustainability of wood-based composites.
   • Methodologies that strike an optimal balance between energy efficiency and long-term durability.

   While not required, proposals in this area could benefit from comparisons between wood-based composites and competing building materials.

3. Long Term Durability

   Understanding, predicting and improving the long term durability and performance of wood-based composites is fundamental to maintaining and expanding the role of these products in building construction. Projects in this area should advance the understanding of failure mechanisms that occur under extreme exposure to moisture, heat, UV radiation, and other stimuli. The cyclic variation and interaction of degradative stimuli should be considered not only for bulk performance but also for interfacial phenomena, distinguishing bulk and interfacial effects where possible.

   General research areas and questions include, but are not limited to:

   1. Examination and definition of failure mechanisms occurring under cyclic moisture conditions, including
      • Cyclic temperature.
      • Bio-deterioration due to fungi and insects, and the effects of current and future preservation methods (chemical modification and non-chemical modifications).
   2. Determination of how production variables impact long term performance, including
      • Wood moisture content at time of bonding; high moisture gluing, etc.
      • Implications of press temperature and energy input on dimensional stability.
      • Press strategies and density profile.
   3. Determination of how resin distribution and bond-line morphology impact long term durability.
   4. Development of improved testing methods to predict long term durability, including
      • Non-destructive test methods.
      • Comparing wood composites with non-wood materials.
   5. Characterization of how prolonged high temperature exposure impacts long term durability.
   6. Understanding the creep behavior and mechanisms of failure under high load and cyclic load conditions.

4. Process Characterization

   Exploring the impact of processing on the properties and behavior of wood-based composites supports product improvement and sustainability. Focus areas of common interest include:

   1. Fundamental understanding and modeling of heat and mass transfer during composite panel (OSB, particleboard, MDF, plywood) hot-pressing, as affected by numerous potentially interacting variables including, but not limited to:
      • Wood species.
      • Wood chemistry (major components – cellulose, hemicelluloses and lignin and minor components – extractives, VOCs).
      • Wood hygrothermal history.
      • Wood particle size and geometry.
   2. Fundamental understanding and modeling resin/adhesive movement (gross flow) and penetration (at multiple scales from microscopic to molecular) during the hot-pressing of wood-based composites as impacted by numerous potentially interacting variables including, but not limited to:
      • Cure rates
      • Wood macroscopic and microscopic structure/geometry
      • Wood chemistry
      • Application methods
      • Heat gradients
      • Moisture gradients
      • Vapor pressure gradients
      • Differences in adhesive components
      • fillers/extenders
      • molecular weight fractions
      • Distribution of cured resin/adhesive
   3. Fundamental understanding and modeling of the impacts of paper or non-paper based overlays applied during the primary hot-pressing of wood-based composites as it relates to:
      • Heat and mass transfer
      • Resin/adhesive movement

5. Sustainable Building Blocks

   The chemical and wood products industries are seeking chemical feedstocks that are derived from non-petrochemical sources. Sustainable alternatives are sought that could feasibly augment and/or replace existing commodity petrochemicals, including but not limited to the following applications:

   • Monomers for contemporary thermosetting and thermoplastic resins
   • Tackifiers
   • Solvents
   • Catalysts
   • Primers
   • Waxes
   • Fillers

   Alternatives could be monomeric to polymeric, and derived from a variety of renewable materials including polysaccharides, lipids, proteins, phenolic and polyphenolic compounds.

6. Wood-Adhesive Interaction

   The study of the behavior and performance of adhesives when applied to different wood species under typical bonding conditions, including the following areas:

   1. Improved understanding of how to influence and optimize penetration for performance.
      • Effects of adhesive viscosity and surface tension, wood surface energy, wood moisture content, wood anatomy, temperature and consolidation pressure.
      • What is sufficient penetration?
      • How does penetration relate to performance?
      • Bleed-though control.
      • Dry-out prevention.
      • Species effects.
      • How do the important aspects of penetration differ by product (e.g. veneer, flakes/strands, particles, fiber, etc)?
   2. Define and characterize the scale of adhesive penetration.
      • Millimeter scale, as per wood machining and machining defects.
      • Micron scale, as per wood anatomy and lumen filling.
      • Nanometer scale, as per cell wall infiltration.
      • What is important?
   3. Material properties of the wood-adhesive interphase.
      • Moisture-related dimensional stability relative to native wood.
      • Stiffness, strength, and toughness of the interphase.
      • Wood-induced alteration of adhesive structure and morphology.
      • Adhesive-induced alteration of wood structure and morphology.
   4. Bonding to chemically and physically modified wood and how this differs from native wood.

7. Wood Polymer Organization

   An improved understanding of the structure and organization of wood-polymers is required to advance many wood-processing technologies. Wood-based composite manufacture imposes a variety of chemical and thermo-mechanical wood treatments, all of which may be studied within the context of polymer structure and organization. Examples include but are not limited to:

   • Wetting by aqueous and non-aqueous liquids.
   • Swelling in aqueous and non-aqueous liquids.
   • Drying of green and also of re-wetted wood.
   • Thermo-mechanical relaxation, both in the linear and non-linear response regions, under a variety of pure and/or mixed stress modes.
   • Wood chemical reactions.
   • Wood enzymatic treatments.

   Research in this area would involve the study of these and other phenomena with an emphasis on refining and advancing current models of wood-polymer structure and organization. Efforts to develop such models through the creation of new materials would also be valued; examples include: novel materials that mimic the structure and organization of lignocellulose, genetic or other manipulations intended to improve wood properties.

• Strand dynamics during the oriented strand composites formation process (S. Perry and S. Shaler)
• Examining the lignin glass transition as a method to screen the effectiveness of wood adhesion coupling agents (J. Hosen)
• Carboxymethylcellulose Acetate/Butyrate (CMCAB) water-dispersions as wood adhesives (J. Paris)
• Mixed mode fracture testing of adhesively bonded wooden specimens(E. Nicoli and D. Dillard)
• New bio-based polymer nanocomposites reinforced with TEMPO-oxidized nanocelluloses (R. Johnson)
• Effect of cellulose nanocrystals on the rheology, curing behavior and fracture performance of phenol-formaldehyde resol resin (J.K. Hong and M. Roman)
• Preparation of labeled isocyanates for wood adhesion research (D. Ren and C. Frazier)
• Development of wood rheology for studying adhesive durability (S. Chowdhury and C. Frazier)
• Effect of heat on wood and wood composite properties (A. Sinha, R. Gupta and J. Nairn)

• Photostabilisation of Thermosetting Adhesives (M. Meisner and P.Evans)
• Characterization of Wood Resin-Adhesive Spray (X. Zhang and D. Gardner)
• Simulation modeling for manufacture of wood fiber thermoplastic composites (J.N. Lee and D. Hindman)
• Mechanical analysis of a moisture-cure polyurethane adhesive: dynamic bending versus oscillatory torsion (C. Heinemann)
• Effects of fungal attack on properties of connections between composite sheathing and studs in wood shear walls (N. Melencion and J. Morrell)
• Nanoscale Surface Modification of Wood Veneers for Adhesion (Z. Yu and S. Renneckar)
• DMA Analysis of Solvent Swollen Balsa Wood (J. Hosen and S. Renneckar)
• Non-destructive evaluation of veneer for use in laminated veneer lumber (LVL) using machine vision and ultrasonic stress wave analysis systems (D. DeVallance and J. Funck)
• Multi-scale characterization of wood-thermoplastic composite materials (Y. Wang and L. Muszynski)
• Effect of adhesive on bond durability and associated smoke toxicity for EWP under high temperatures (S. Shi)
• Defining moisture and temperature limits for decay in wood-based composites for use in developing service-life model (S. Shi)
• Applying micro-nano scratch/indentation method to characterize the interfacial bonding shear strength (IBSS) for wood composites and wood-polymer composites (M. Barnes and S. Shi)
• Cellulose fibrils reinforced polymer composites (W. Tze)
• Parallel-plate rheology of polyurethane adhesives in contact with wood (C. Heinemann)
• Polyelectrolytes as adhesives (S. Renneckar)
• Wood/adhesive interactions in a PVAc Latex System (C. Frazier and F.Lopez-Suevos)
• Analysis of structural composite lumber loaded by dowels in perpendicular to grain orientation at yield and capacity (D. Finkenbinder and D. Hindman)
• Coupling model analysis of stress relaxation behavior in Yellow-poplar/HMR system. (N. Sun)
• Hybrid thermosetting wood adhesives: optimized performance through tailored emulsions. (D. Riedlinger)
• Investigation of Tg as a measure of cure in wood/pMDI systems. (N. Sun)
• Characterization of PF resol/isocyanate hybrid adhesives (D. Riedlinger)
• Using fire-killed trees for wood-based composites (L Moya and S. Ramaswamy)
• Comparison of Shear Modulus Test Methods (S.K. Harrison and D. Hindman)
• The Influence of Phenolic Additives of PVAc Latex Adhesive Performance (F. Lopez Suevos)
• Improved Interfacial Adhesion in Wood-Plastice Composites: Developments of New Compatibilizers (C. Zhang and K.Li)
• A Preliminary Investigation Of The Properties of Engineered Wood Composite Panels Treated With Copper Naphthenate (J. Kirkpatrick & M. Barnes)
• Dynamic Mechanical Analysis of the Interphase Morphology of Wood-polymeric Isocyanate Bond-lines (S. Das)
• WBC Sim (hot pressing model) (J. Lee,J. Shu and L. Watson)
• Natural Fiber Reinforced Thermoplastic Composites from the Wetlay Process (R. Johnson)
• Effect of Grain Direction on the Dynamic Mechanical Analysis of Wood (S. Das)
• Cure Characterization of a Phenol-formaldehyde Adhesive (b. Scott)
• Dielectric Characterization of Phenol-formaldehyde Cure (b. Scott)
• Hydro-thermal Stabilization of Wood-based Materials (M. Reynolds)
• Effects of Moisture Cycling on the Shear Strength Properties of OSB (N. Deringer)
• Changes in OSB Mat Permeability During Hot-pressing (J. Hood)
• Modification of Wood Fiber with Thermoplastics by Raxtive Steam-Explosion Processing (S. Renneckar)
• An Investigation of Nail Connection Performance in a Cyclic-humidity Conditioned Environment (J. Smith)
• Incentives/Barriers to the Increased Utilization of Wood-Based Structural Panels in Industrial Markets (D. Gilbert, D. Bailey, P. Duvall)
• Infrared Microscopy and Confocal Laser Scanning Microscopy Analysis of Polyolefin Modified Wood Fibers (S. Renneckar)
• Investigating the Surface Energy and Bond Performance of Compression Densified Wood (J. Jennings)
• Self-assembly of Pullulan Abietate (S. Gradwell)
• Studies of PF Resole / Isocyanate Hybrid Adhesives (J. Zheng)
• Molecular Aspects of Performance in Crosslinking PVA Latex Adhesives (N. Brown)
• Rheology of Powdered Phenol Formaldehyde Adhesives (D. Riedlinger)
• Developing the Basis for Capacity Design of Connections (J. Smart)
• Investigation of the Wood / Phenol-Formaldehyde Adhesive Interphase Morphology (M. Laborie)
• Wood Magic in a Distance Education Format (C. Pugh)
• Comparative Analysis of Inactivated Wood Surfaces (M. Sernek)
• Characterizing the Durability of PF and pMDI Adhesives Through Fracture Testing (C. Scoville)
• Mechanism of Flake Drying and Its Correlation to Quality (E. Deomano)
• Improvements in the Fracture Cleavage Testing of Adhesively-Bonded Wood (J. Gagliano)
• Modeling the Transient Effects during the Hot-Pressing of Wood-Based Composites (b. Zombori)
• Feasibility of Implementing a Resin Distribution Measurement System for MDF Fiber (K. Scott)
• Public Perceptions of the U.S. Forest Products Industry (P. Uhrig)
• Wood Material Behavior in Severe Environments (C. Lenth)
• Analysis of Calcutta Bamboo for Structural Composite Materials (M. Ahmad)
• Analysis and Testing of a Ready-to-Assemble Wood Framing System (V. Kochkin)
• The Wood Species Dependence of pMDI Adhesive Performance (M. Malmberg)