ИСТИНА

High modulus and high strength fibers for GRP (glass fiber reinforced plastics) are of particular interest to production of longer wind turbine blades in the renewable energy market. Basalt continuous fibers (BCF) are perspective material for this purpose due to its higher tensile strength and E-modulus (2800 - 3200 MPa, 60 - 70 GPa). BCF exceed the widely used E-glass fibers in mechanical properties (2500 - 2800 MPa, 45 - 60 GPa), but concede to the S-glass fibers (3500 - 4000 MPa 80 - 90 GPa). Furthermore, GRP based on basalt fiber can be easily recycled than ordinary GRP. The aim of this study was to obtain BCF with improved mechanical properties. Object of research was eight-component system Na2O-K2O-MgO-CaO-FeO-Fe2O3-SiO2-Al2O3. Andesite basalt was used as a raw material. BCF with various contents of network formers (SiO2, Al2O3) and modifiers (MgO, CaO, ZnO) oxides were obtained. Based on "composition - structure - mechanical properties" relationships the follows methods for BCF surface modification were developed: weak acid solution treatment, short-term heat treatment under load, application of sizing agent dispersed by ultrasonic bath . The tensile strength and Young's modulus of BCF under study were amounted to 2700±250 MPa and 79±3 GPa respectively. Mechanical properties of basalt fibers were determined according to ISO 5079 Complex structure research was carried out using IR-, Raman- and NMR spectroscopy. Scanning electron microscopy, EDX and optical analysis were used for detection of nano- and microdefects on the fiber surface.