Composites based on polymeric blends reinforced with TiO₂ modified aramid fibers

The paper presents a study on composites based on 50:50 (PP:LLPE-g-MA) reinforced with 0.5, 1, and 2 wt% aramid fibers unmodified/modified with TiO2, processed by melt compounding. Micronic aramid fibers were acetone washed to remove impurities and treated with Ti(IV)isopropoxide precursor via sol-gel method, adding microcellulose for TiO2 particle dimension control. Composites were hot-pressed into 4 mm-thick plates for sampling and 0.5 mm-thick sheets for thermoforming. All composites were successfully thermoformed, fibers-based samples showing improved thermoforming ability without wrinkling. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and Energy dispersive X-ray spectroscopy (EDS) analysis confirmed the formation of TiO2 particles on the fiber surface. Optical microscopy, SEM and FTIR analysis exhibit the fibers' strong embedment into the matrix due to physical interlocking, generating surface defect reduction. Water absorption decreased from 0.195% (control) to 0.075 and 0% for 1 TiO2 and 2 TiO2 samples, due to material compactization. Contact angles increased from 95.18 degrees (Control) to 108 degrees (1 TiO2) and 112.89 degrees (2 TiO2). The highest flexural strength and modulus were exhibited by 1 TiO2 sample that increased by 44.88% and 47.6% compared to the control sample, due to higher intrinsic rigidity of fibers and TiO2 modifying surface rugosity and phase interaction. The impact strength of the control sample improved by 139% compared to PP due to brittleness reduction, 1 TiO2 by 209% compared to PP, 29% compared to the control sample. The results and excellent thermoformability recommend the materials for encapsulation of electronic/expensive parts in automotive or drone applications, offering viable, facile, rapid, and cost-effective solutions to easily replace damaged parts.