Enhanced performance of rosin-based epoxy composites mixed with carbon nanotubes and cork powders from oriental oak bark

Abstract Rosin-based epoxy composites with high-impact toughness, tensile strength, modulus, and excellent flame retardance were prepared through a simple and effective approach. In this study, rosin-based epoxy resin (acrylopimaric diglycidyl ester, APA-ER) was synthesized from rosin, and the chemical structures of the products were determined by 1H NMR and FT-IR. The multiwalled carbon nanotubes (MWCNTs) and cork powders were introduced to the APA-ER to enhance the mechanical and thermal properties of epoxy composites. For the first time, cork powder was used to reinforce the modified rosin-based epoxy resin. Testing results of the mechanical properties indicated that the impact toughness of epoxy composite with 1.5 wt% MWCNTs and 3 wt% cork powders (100–200 mesh) had the highest value (12.34 and 12.04 kJ m−2), which was increased by 324% and 314%, respectively, compared to pure resin (2.91 kJ m−2). The composites with 1.5 wt% MWCNTs displayed better flexural and tensile performance compared to APA-ER/Cork. Moreover, the DMA, TG, and cone calorimeter results showed that APA-ER/Cork had a better performance in thermal stability and flame retardance than APA-ER/MWCNTs. Additionally, the flame retardance of rosin-based epoxy resin was further improved by adding MWCNTs and cork powder simultaneously. These results showed that the rosin-based epoxy resin could be toughened and strengthened effectively, and the thermal performance was improved by MWCNTs and cork powders. In conclusion, the value-added development of rosin and cork products was increased and applied in the field of functional materials.