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

Publications Kaboorani, A.; Riedl, B. (2013). Efficiency of Ultrasonication Technique in Dispersion of Nano-clay in Polyvinyl Acetate (PVA) adhesive. Nanomaterials Journal. Volume 2013. http://dx.doi.org/10.1155/2013/341897 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.

Table of Content Introduction Objective Materials and Methods Results Conclusions Acknowledgements

Introduction

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

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....

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

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 ......

Objective; Development of adhesives with improved properties through nanotechnology

Materials and Methods

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

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)

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 7247-07

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

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

Results

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

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

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

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

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

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

TEM images of PVA-Lit.G-105 nano-composites with different nano-clay loadings agglomerated zone 1% Lit.G-105 2% Lit.G-105 4% Lit.G-105

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

Conclusions

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 %

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

Acknowledgements

Thank you very much for your attention Alireza Kaboorani Research Scientist Centre de recherche sur les matériaux renouvelables (CRMR) alireza.kaboorani.1@ulaval.ca Thank you very much for your attention Merci beaucoup pour votre attention