Dynamic-Mechanical and Decomposition Properties of Flax/Basalt Hybrid Laminates Based on an Epoxidized Linseed Oil Polymer

This contribution focuses on the development of flax and flax/basalt hybrid reinforced composites based on epoxidized linseed oil (ELO) resin, exploiting the feasibility of different ratios of glutaric anhydride (GA) to maleinized linseed oil (MLO) in the hardener system (50:0, 40:10 and 30:20 wt.%) to provide crosslinked thermosets with balanced properties. The hybrid laminates have been manufactured by resin transfer molding (RTM) and subjected to dynamic-mechanical (DMA) and thermal gravimetry (TGA) analysis. The presence of glutaric anhydride (GA) resulted in hard and relatively brittle flax and flax/basalt laminates, whose loss moduli decreased as the number of basalt plies diminished. Furthermore, the increase in MLO content in the GA:MLO hardener system shifted the glass transition temperatures (T-g) from 70 degrees C to 59 and 56 degrees C, which is representative of a decrease in brittleness of the crosslinked resin. All samples exhibited two stages of their decomposition process irrespective of the MLO content. The latter influenced the residual mass content that increased with the increase of the MLO wt.% from 10 to 30 wt.%, with shifts of the final degradation temperatures from 410 degrees C to 425 degrees C and 445 degrees C, respectively.

Automated summary

This study focused on the development of flax and flax/basalt hybrid reinforced composites using epoxidized linseed oil resin, with different ratios of glutaric anhydride and maleinized linseed oil in the hardener system. The addition of glutaric anhydride resulted in hard and brittle laminates, while increasing MLO content led to a decrease in brittleness of the crosslinked resin. The thermal analysis showed shifts in glass transition temperatures and final degradation temperatures with varying MLO content.