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Rheology of latex films bonded to wood: influence of cross-linking

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Veröffentlicht/Copyright: 17. Januar 2006
Holzforschung
Aus der Zeitschrift Band 60 Heft 1

Abstract

Parallel-plate rheological analysis was conducted on two types of cross-linking poly(vinyl acetate) latex films: dry freestanding films, and dry films bonded directly to wood (composites). For each sample type, three levels of cross-linking were used: (1) little or no cross-linking of unaltered latex; (2) substantial cross-linking through AlCl3 catalysis of N-methylolacrylamide co-monomer; and (3) greater cross-linking from a phenol-formaldehyde resol additive, in addition to AlCl3 catalysis. Simple thermal scans revealed a strong wood/adhesive interaction; wood increased the base polymer Tg by ∼5°C in all adhesives. Relative to the simple thermal scans, time-temperature master curves provided more insight and information about the wood/adhesive interaction. Storage modulus and tan δ master curves both indicated that wood retarded adhesive cross-linking. Using time-temperature superposition, a segmental coupling analysis demonstrated that wood actually narrowed the breadth of the glass transition, or reduced segmental coupling. Cross-linking influenced segmental coupling, but in a fashion that was dependent on the presence or absence of wood. Wood-induced reductions in cross-linking and in segmental coupling were attributed to the diffusion of water-soluble reactive compounds away from the adhesive layer and into the bulk wood. Time/temperature equivalence provides a sensitive means to detect interactions between wood and viscoelastic adhesives.

Keywords: glass transition; latex adhesives; rheology; wood/adhesive interactions
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Corresponding author. Charles E. Frazier, Department of Wood Science and Forest Products, Virginia Tech, 230 Cheatham Hall, Blacksburg, VA 24061-0323, USA Fax: +1-540-231-8176

References

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Published Online: 2006-01-17
Published in Print: 2006-01-01

©2006 by Walter de Gruyter Berlin New York

Artikel in diesem Heft

  1. Morphological and chemical variations between juvenile wood, mature wood, and compression wood of loblolly pine (Pinus taeda L.)
  2. XPS in combination with mercurization – incorporation of mercury into different morphological parts of an unbleached softwood kraft pulp
  3. Comparison of different XPS methods for fiber surface analysis
  4. Antifungal diterpenes from the bark of Cryptomeria japonica D. Don
  5. Rapid analysis of transgenic trees using transmittance near-infrared spectroscopy (NIR)
  6. Calibration of NIR to assess lignin composition (H/G ratio) in maritime pine wood using analytical pyrolysis as the reference method
  7. Dissolution of fibre material in alkaline pre-treatment and refining of spruce CTMP
  8. Creating water-repellent effects on wood by treatment with silanes
  9. Rheology of latex films bonded to wood: influence of cross-linking
  10. Reinforcing potential of wood pulp-derived microfibres in a PVA matrix
  11. Diffusion of tritiated water into water-saturated wood particles
  12. Interrelationship between the severity of heat treatments and sieve fractions after impact ball milling: a mechanical test for quality control of thermally modified wood
  13. Machinability investigation of medium-density fibreboard
  14. Rolling shear modulus and damping factor of spruce and decayed spruce estimated by modal analysis
  15. Structural changes in activated wood-based carbons: correlation between specific surface area and localization of molecular-sized pores
  16. Distribution and characterisation of discolouring substances in Norway spruce (Picea abies L. Karst.) pulp wood stored under water sprinkling
  17. Decay resistance, extractive content, and water sorption capacity of Siberian larch (Larix sibirica Lebed.) heartwood timber
  18. Biological resistance of wood treated with zinc and copper metaborates
https://doi.org/10.1515/HF.2006.009
Schlagwörter für diesen Artikel
glass transition; latex adhesives; rheology; wood/adhesive interactions

Artikel in diesem Heft

  1. Morphological and chemical variations between juvenile wood, mature wood, and compression wood of loblolly pine (Pinus taeda L.)
  2. XPS in combination with mercurization – incorporation of mercury into different morphological parts of an unbleached softwood kraft pulp
  3. Comparison of different XPS methods for fiber surface analysis
  4. Antifungal diterpenes from the bark of Cryptomeria japonica D. Don
  5. Rapid analysis of transgenic trees using transmittance near-infrared spectroscopy (NIR)
  6. Calibration of NIR to assess lignin composition (H/G ratio) in maritime pine wood using analytical pyrolysis as the reference method
  7. Dissolution of fibre material in alkaline pre-treatment and refining of spruce CTMP
  8. Creating water-repellent effects on wood by treatment with silanes
  9. Rheology of latex films bonded to wood: influence of cross-linking
  10. Reinforcing potential of wood pulp-derived microfibres in a PVA matrix
  11. Diffusion of tritiated water into water-saturated wood particles
  12. Interrelationship between the severity of heat treatments and sieve fractions after impact ball milling: a mechanical test for quality control of thermally modified wood
  13. Machinability investigation of medium-density fibreboard
  14. Rolling shear modulus and damping factor of spruce and decayed spruce estimated by modal analysis
  15. Structural changes in activated wood-based carbons: correlation between specific surface area and localization of molecular-sized pores
  16. Distribution and characterisation of discolouring substances in Norway spruce (Picea abies L. Karst.) pulp wood stored under water sprinkling
  17. Decay resistance, extractive content, and water sorption capacity of Siberian larch (Larix sibirica Lebed.) heartwood timber
  18. Biological resistance of wood treated with zinc and copper metaborates
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