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Impact of water absorption on the creep performance of epoxy/microcrystalline cellulose composites |
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| Authors: | Alessandra Lavoratti Otávio Bianchi Joziel A Cruz Zainab Al-Maqdasi Janis Varna Sandro Campos Amico Roberts Joffe |
| Affiliation: | 1. Department of Materials, Federal University of Rio Grande do Sul–UFRGS, Porto Alegre, RS, Brazil;2. Department of Materials, Federal University of Rio Grande do Sul–UFRGS, Porto Alegre, RS, Brazil
Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, SE, Sweden Contribution: Formal analysis (equal), ?Investigation (equal), Methodology (equal), Writing - original draft (equal), Writing - review & editing (equal);3. Department of Materials, Federal University of Rio Grande do Sul–UFRGS, Porto Alegre, RS, Brazil Contribution: Data curation (supporting), Methodology (supporting);4. Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, SE, Sweden Contribution: Data curation (equal), Formal analysis (equal), Methodology (equal), Writing - review & editing (supporting);5. Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, SE, Sweden Contribution: Data curation (supporting), Methodology (supporting), Supervision (supporting);6. Department of Materials, Federal University of Rio Grande do Sul–UFRGS, Porto Alegre, RS, Brazil Contribution: Funding acquisition (lead), Supervision (lead), Writing - review & editing (supporting);7. Department of Engineering Sciences and Mathematics, Luleå University of Technology, Luleå, SE, Sweden Contribution: Funding acquisition (lead), Resources (lead), Supervision (lead), Writing - review & editing (supporting) |
| Abstract: | Recently, considerable effort has been made to study cellulose/epoxy composites. However, there is a gap when it comes to understanding the post-conditioning anomalous effect of moisture uptake on their mechanical and dynamic-mechanical properties, and on their creep behavior. In this work, up to 10.0 wt% microcrystalline cellulose (MCC) was incorporated into epoxy resin by simple mixing and sonication. Epoxy/MCC composites were fabricated by casting in rubber silicone molds, and rectangular and dog-bone test specimens were produced. The moisture uptake, dynamic mechanical, chemical, tensile, and creep behavior were evaluated. The incorporation of MCC increased the water diffusion coefficient. The changes in storage modulus and glass transition temperature, combined with Fourier-transform infrared spectroscopy analysis, evidenced that water sorption in epoxies causes both plasticization and additional resin crosslinking, although the latter is prevented by the addition of MCC. The creep strain of the composites increased by 60% after conditioning, indicating that plasticization induced by water sorption plays an important role in the long-term properties of the composites. |
| Keywords: | cellulose and other wood products mechanical properties thermosets |