1. Alireza Kaboorani Bernard Riedl
Wood Adhesives and Nanotechnology
Alireza Kaboorani Bernard Riedl
Laval University
Quebec City, Canada

2. Publications
Kaboorani, A.; Riedl, B. (2013). Efficiency of Ultrasonication Technique in Dispersion of Nano-clay in Polyvinyl Acetate (PVA) adhesive. Nanomaterials Journal. Volume
Kaboorani, A.; Riedl, B.; Blanchet, P.; Fellin, M.; Hosseinaei, O; Wang, S.(2012).Nanocrystalline Cellulose (NCC): A Renewable Nano-Material for Wood Adhesives. European Polymer Journal. Vol.48; pp. 1829–1837.
Kaboorani, A.; Riedl, B.(2012). Nano- Aluminum Oxide as a Reinforcing Material for Thermoplastic Adhesives. Journal of Industrial and Engineering Chemistry.Vol.18; pp. 1076–1081.
Kaboorani, A.; Riedl, B. (2011).Improving Performance of Polyvinyl Acetate (PVA) as a Wood Adhesive by Combination with Melamine Based Adhesives. International Journal of Adhesion and Adhesives. Vol. 31; pp.605–611.
Kaboorani, A.; Riedl, B. (2011).Effects of Addition of Nano-Clay on Performance of Polyvinyl Acetate (PVA) as a Wood Adhesive. Composites: Part A. Vol.42; pp.1031–1039.

3. Table of Content Introduction Objective Materials and Methods Results
Conclusions
Acknowledgements

4. Introduction

5. An increase in usage of adhesives in wood industry as solid wood replaced by engineered wood products (EWP) in last decades
Important role of adhesives in durability of wood products
Commercial durable wood adhesives contain formaldehyde, causing health problems in the production and the service

6. Polyvinyl acetate (PVA):
A thermoplastic polymer
Borad range of applications
A water based polymer
Several advantages:
Ease of application
Low cost
Not containing formaldehyde
But a big drawback....

7. Poor performance towards elevated temperatures and humid conditions
Drawback
Poor performance towards elevated temperatures and humid conditions
Solutions:
(1) Polymerization of PVA with hydrophobic monomers or functional monomers
(2) Blending PVA with other adhesives or hardener
Not perfect solutions: increase some properties of PVA at the expense of reducing some other properties

8. Nanotechnology: many applications
Little is done to materialize positional advantages of nanotechnology in wood adhesives
Past research: positive impact of nanotechnology on polymers properties;
mechanical performance
thermal stability
barrier properties and

9. Objective;
Development of adhesives with improved properties through nanotechnology

10. Materials and Methods

11. Materials Adhesive: Polyvinyl acetate (PVA), commercial grade
Wood substrates:Sugar maple (Acer saccharum) and Black spruce (Picea mariana)
Nano-clay, hydrophilic: Nanofil 116(Southern Clay
Products) & Lit. G-105 (Nanocor Inc.)
Nanocrystalline cellule (NCC)
Variable nano-particles loadings

12. Characterizations
Mechanical properties: block shear test of wood joints in dry and wet conditions, as well an elevated temperature
Structural characterizations:
Transmission electron microscopy (TEM)
Atomic Force microscopy(AFM)

13. Block shear tests:
Dry state: Block shear samples, according to ASTM D905-98
Wet state: Block shear samples, conducted after spending 24 hours in water
Elevated temperature: Block shear samples conducted at 100°C according to ASTM

14. Transmission electron microscopy (TEM)
Apparatus: JEOL, JEM-1230 transmission electron microscope
Magnification: 100 nm

15. Atomic force microscope ( AFM)
NanoScope : Veeco Instruments Inc.
Mode: Trapping mode
Calculation of surface roughness

16. Results

17. Shear strength measured on the sample in dry state(PVA + nano-clay).

18. Shear strength measured on the samples after spending 24 hours in water(PVA + nano-clay).

19. Shear strength measured on block shear samples at 100°C (PVA+nano-clay).

20. Shear strength measured on block shear samples in dry state(PVA+NCC)

21. Shear strength measured on block shear samples after spending 24 hours in water(PVA+ NCC).

22. Shear strength measured on block shear samples at 100°C (PVA+ NCC).

23. TEM images of PVA-Lit.G-105 nano-composites with different nano-clay loadings
agglomerated zone
1% Lit.G % Lit.G % Lit.G-105

24. AFM images for PVA/ NCC nano-composites: surface roughness
Pure PVA
1% NCC
2% NCC
3% NCC

25. Conclusions

26. Nano-clay:
Positive effects (not significant) of nanoclay on bonding strength of PVA in dry state
Significant effects of nanoclay on water resistance of PVA
Improvement in water resistance is proportional to nano-clay loading
Good dispersion at low loadings (1 and 2%) exfoliated structures
Coexistence of exfoliated and intercalated structures at 4 %

27. NCC:
Shear strength in dry state: Increase in wood failure percentage-positive effects
Shear strength in wet state: significant gain, almost doubled
Shear strength at the elevated temperature: A significant increase
Good dispersion of nanocellulose at 1% loading: Low surface roughness
Difficulty in dispersing nanocellulose at 2% and 3% loadings: High surface roughness

28. Acknowledgements

29. Thank you very much for your attention
Alireza Kaboorani Research Scientist
Centre de recherche sur les matériaux renouvelables (CRMR)
Thank you very much for your attention
Merci beaucoup pour votre attention