Influence of cellulose nanofibers on the curing behavior of epoxy/amine systems

• Autocalytic model is better suited than nth order model to describe the kinetic behavior of the cellulose-epoxy systems.
• The Ea values decreased in the presence of cellulose nanofibers and increased in the presence of DMF.
• Compared to Kamal model, the S–B model gave a better description of the experimental data.

Epoxy composites were prepared using diglycidyl ether bisphenol F and water-dilutable diglycidyl ether bisphenol A with curing agents, polyoxypropylenediamine and diethylmethylbenzenediamine, in water or dimethylformamide as a solvent. The influence of cellulose nanofibers and solvents on curing kinetics of epoxy composites was investigated. Curing kinetic parameters were calculated using the model-fitting methods and the isoconversional method. Among these, the Sestak–Berggren equation best fit the experimental data. Results indicated that dimethylformamide decreased the reaction rate, whereas water revealed the opposite pattern. Cellulose nanofibers catalyzed the reaction between bisphenol F resins and the aromatic curing agent.

Figure optionsDownload as PowerPoint slide