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Alkyl-Chitosan-Based Adhesive: Water Resistance Improvement
Narimane Mati-Baouche1,2,3, Cédric Delattre4, Hélène de Baynast5
1Clermont Auvergne University, CNRS, SIGMA Clermont, Institut Pascal, F-63000 Clermont-Ferrand, France. narimane.mati@univ-rouen.fr.
Molecules (Basel, Switzerland)
|May 26, 2019
Summary
Grafting octanal chains onto chitosan (alkyl-chitosan) enhances water resistance and viscosity for bonding applications. Alkyl-chitosans show maintained adhesive properties, especially on wood, compared to native chitosan.
Area of Science:
- Polymer Chemistry
- Materials Science
- Surface Modification
Background:
- Chitosan, a natural polymer, has limited water resistance, hindering its use in bonding applications.
- Chemical modification is explored to enhance chitosan's properties for improved performance.
Purpose of the Study:
- To improve the water resistance of chitosan for bonding applications by grafting octanal (C8) alkyl chains.
- To evaluate the impact of this modification on the flow properties and adhesive strength of chitosan.
Main Methods:
- Chemical modification of chitosan using octanal to create alkyl-chitosans with varying alkylation degrees (10% and 15%).
- Nuclear Magnetic Resonance (NMR) spectroscopy for structural characterization.
- Rheological measurements to assess solution viscosity.
- Adhesive strength testing (bond strength and shear stress) on aluminum and wood adherends.
Main Results:
- NMR analysis confirmed the successful grafting of alkyl chains, with achieved alkylation degrees of 10% and 15%.
- Alkyl-chitosan solutions exhibited increased viscosity compared to native chitosan solutions at equivalent concentrations.
- Alkyl-chitosans demonstrated maintained adhesive properties on wood and improved water resistance over native chitosan.
Conclusions:
- Octanal grafting effectively enhances the water resistance of chitosan.
- The modified chitosan (alkyl-chitosan) offers improved flow properties and retains adequate adhesive strength, particularly for wood bonding.
- Alkyl-chitosan presents a promising alternative to native chitosan in applications requiring enhanced water resistance and specific adhesive characteristics.
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