In situ functionalisation of organomineral hybrid resins for tough basalt fibre reinforced plastics

This work addresses the usability of novel and sustainable basalt fibre reinforced composites (BFRP) with special emphasis to their structural integrity and fracture toughness GIc, compared to state-of-the-art ECR glass fibre composites (GFRP). Toughness was determined via Double Cantilever Beam (DCB) tests and evaluated both the Area Method (AM) and Corrected Beam Theory (CBT) yielding equivalent results. The organomineral matrix (3P Resin®) was made from (poly)isocyanate, water glass, and an environmentally unfavourable phosphate emulsifier. Phosphate was substituted by renewable oil (denoted as 2P resin) what reduced composites' toughness, and thus an in situ functionalisation by silane-terminated polyurethane (STP-U) was performed. Consequently, the 2P/STP-U resin proved better adhesion to fibres and strongly enhanced toughness. GIc exceeded the conventional 3P composites by 50% (BFRP) and 88% (GFRP), respectively. If both tough and highly sustainable composites are required at the same time, the BFRP with 2P/STP-U is superior to the GFRP solution.
This work addresses the usability of novel and sustainable basalt fibre reinforced composites (BFRP) with special emphasis to their structural integrity and fracture toughness GIc, compared to state-of-the-art ECR glass fibre composites (GFRP). Toughness was determined via Double Cantilever Beam (DCB) tests and evaluated both the Area Method (AM) and Corrected Beam Theory (CBT) yielding equivalent results. The organomineral matrix (3P Resin®) was made from (poly)isocyanate, water glass, and an environmentally unfavourable phosphate emulsifier. Phosphate was substituted by renewable oil (denoted as 2P resin) what reduced composites' toughness, and thus an in situ functionalisation by silane-terminated polyurethane (STP-U) was performed. Consequently, the 2P/STP-U resin proved better adhesion to fibres and strongly enhanced toughness. GIc exceeded the conventional 3P composites by 50% (BFRP) and 88% (GFRP), respectively. If both tough and highly sustainable composites are required at the same time, the BFRP with 2P/STP-U is superior to the GFRP solution.