Interfacial and mechanical properties of silane coupling agent interface‐modified basalt fiber reinforced thermoplastic polypropylene resin composites

Abstract Basalt fiber (BF)‐reinforced thermoplastic composites are not only made with little environmental pollution and recyclable, with obvious environmental value, but also have excellent mechanical properties, excellent resistance to high temperature and corrosion. In the present study, modifications to the interface of BF were performed using monoaminosilane and diaminosilane agents, specifically 3‐aminopropyltrimethoxysilane (SATMS) and N‐(2‐aminoethyl)‐3‐aminopropyltrimethoxysilane (DATMS), along with a urea‐modified silane, 3‐urethylpropyltrimethoxysilane (SUTMS). These modifications were evaluated against one another. Utilizing a film lamination technique, composites of BF and thermoplastic polypropylene resin (BF‐PP) were fabricated. Analytical assessments included examining the modified fibers' surface morphology, chemical structure, and roughness. Mechanical assessments of the modified BF‐PP composites were conducted, revealing that composites treated with the urea‐inclusive silane agent (BF/SUTMS‐PP) exhibited superior performance, enhancing flexural strength by 26%, tensile strength by 22.4%, and notched Izod impact strength by 21%. However, because of the lower thermal stability of SUTMS, when the processing temperature exceeds 240°C, there is a decomposition of the heated Y‐base end, thus affecting the mechanical properties of BF/SUTMS‐PP. Highlights The basalt fibers were modified by SATMS, DATMS, and SUTMS. The urea‐containing silane coupling agent has the strongest enhancement effect. Composite reinforced with SUTMS‐BF displayed the best mechanical properties.