Kaya, YahyaBalci, PetekOzen, SuleymanMardani, AliKara, Ali2026-02-082026-02-0820252073-4360https://doi.org/10.3390/polym17233206https://hdl.handle.net/20.500.12885/6073This study investigates the effect of sodium-silicate-based chemical surface modification of polypropylene (PP) fibers on the mechanical and fresh-state properties of cementitious composites. The proposed method introduces silanol and siloxane groups onto the PP surface through a radical-assisted chlorination route, aiming to enhance fiber-matrix interfacial bonding. Modified fibers increased the polycarboxylate ether (PCE) demand by 100% compared to the control mixture, while unmodified PP fibers caused a 58% increase at equivalent workability. The incorporation of PP fibers resulted in limited changes in compressive strength (1-7%), whereas silicate-modified fibers led to notable late-age flexural strength gains of 10% (28 days) and 17% (56 days). Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy (SEM-EDX) and Fourier Transform Infrared Spectroscopy (FTIR) analyses confirmed successful surface functionalization, while the heterogeneous silicate deposition still contributed positively to interfacial transition zone (ITZ) performance. Overall, sodium-silicate-modified PP fibers improve flexural behavior and interfacial bonding in cement-based systems, offering a promising approach for enhanced mechanical performance and sustainability.eninfo:eu-repo/semantics/openAccessPP fibercementitious systemsodium silicatepozzolanic propertiesArticle10.3390/polym172332061723WOS:0016343759000012-s2.0-10502456610941374893Q1Q1