No abstract

No abstract

This work addresses the usability of novel and sustainable basalt fibre reinforced composites (BFRP) with special emphasis to their structural integrity and fracture toughness G Ic , 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 silaneterminated polyurethane (STP-U) was performed. Consequently, the 2P/STP-U resin proved better adhesion to fibres and strongly enhanced toughness. G Ic 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.

In this work newly developed phosphate-free polyurea/polysilicate resins (denoted as 2P) were explored and compared to market established 3P Resins® regarding their fiber/matrix adhesion with coupling agents introduced for further property improvement. Fiber/matrix adhesion was determined by macro mechanical test, i.e. interlaminar shear strength (ILSS), double-cantilever beam (DCB), Charpy impact, and tensile tests.It was demonstrated that 2P resins containing epoxidized linseed oil (ELO) replacing unfavorable organic phosphate esters in 3P Resins® as phase transfer agents nearly reach similar adhesion properties between fiber and matrix compared to established 3P Resins®. Additionally, some coupling agents were found to increase the ILSS by up to 26 %, the energy release rate by up to 7 %, the Charpy impact strength by up to 18 %, and the tensile modulus by up to 11 %.

No abstract