Transparent Dioxaborolane Acrylate Vitrimers Through One-Pot Reaction with Superior Strength as Matrix Material for Carbon Fibers and TiO2 Nanoplates
This study presents an innovative approach to synthesizing multi-reprocessable materials by combining acrylates with dynamic dioxaborolane chemistry. The presented method enables a rapid, solvent-free, and cost-effective synthesis with a tetrafunctional linker to create highly crosslinked materials. The optically transparent vitrimers exhibit a glass transition temperature (Tg,DMA(6.28 rad s -1 )) of 58 °C and a low activation energy of 33.4 kJ mol−1, allowing for robust thermosetting polymers with exceptional thermal stability – demonstrated by a thermal degradation temperature of 305 °C. The stress-relaxation dynamics shows a rapid relaxation in 18 seconds at 110 °C. Static stress-relaxation experiments are analyzed using a stretched exponential fit. Furthermore, frequency sweep measurements are used to determine the stress-relaxation properties and to discuss the applicability of two models to fit the stress-relaxation data after annealing. In tensile test, the materials display an elastic modulus of 1.9 GPa and a tensile strength at maximum elongation of 58 MPa at room temperature after 20 recycling cycles. Finally, potential applications as matrix material for carbon fiber mesh composites or titanium dioxide nanoplates (50 wt.%) are presented.