Biobased Epoxidized Starch Wood Adhesives: Effect of Amylopectin and Amylose Content on Adhesion Properties
| Autor: | Pitchaimari Gnanasekar, Nicolas R. Tanguy, Nicole Tratnik, Ning Yan, Pei-Yu Kuo |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Yellow birch
Starch General Chemical Engineering 02 engineering and technology 010402 general chemistry 01 natural sciences chemistry.chemical_compound Amylose Environmental Chemistry biology Renewable Energy Sustainability and the Environment food and beverages General Chemistry Epoxy 021001 nanoscience & nanotechnology Grafting biology.organism_classification 0104 chemical sciences chemistry Chemical engineering visual_art Amylopectin Diethylenetriamine visual_art.visual_art_medium Adhesive 0210 nano-technology |
| Zdroj: | ACS Sustainable Chemistry & Engineering. 8:17997-18005 |
| ISSN: | 2168-0485 |
| Popis: | Formaldehyde-free, water-resistant, and environmentally friendly wood adhesives were prepared from starches via a simple one-step epoxidation reaction followed by cross-linking using diethylenetriamine. This study focused on the effect of amylose/amylopectin ratio of starch (high amylose, low amylose, and amylopectin) on the epoxidation reaction and on the bonding performance of the prepared epoxidized starches. The epoxidation of starches altered the fluid behavior of the resins, from Newtonian for pristine epoxy to shear thinning, that corroborated the successful integration of starch chains as part of the epoxy resin. Epoxidized amylopectin had the highest viscosity, 114 Pa.s, and a high degree of substitution, 2.33 ± 0.10, among the starches that indicated that amylopectin is more favorable for the grafting of epoxy groups and for the integration of starch chains in epoxy resins compared to the starches with high amylose content. Bonding strengths were determined by lap shear tests on yellow birch specimens in dry, wet, and boiled conditions. High amylopectin epoxidized starch showed the highest lap shear bonding performance under wet conditions (5.50 ± 0.451 MPa). Under boiled conditions, all three epoxidized starches showed equally better performance than the unreacted starch-filled epoxy blends. This study provides fundamental insights into the effect of starch molecular structure on epoxidation reaction and adhesion properties and suggests a promising approach for developing strong formaldehyde-free sustainable biobased wood adhesives. |
| Databáze: | OpenAIRE |
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