Development and characterization of structural composites using waste plastic core, rough cellular leather, and glass fiber-reinforced plastic additives: concept of waste recycling

This study investigates the mechanical, wear, water absorption, and flammability
properties of vinyl ester composites reinforced with recycled PET core, industrial
tanned leather, and silane-treated GFRP filler, offering a novel approach for sustainable material production. The composites were prepared by combining vinyl ester
resin with varying amounts of GFRP filler (1 vol.%, 3 vol.%, and 5 vol.%) and 40
vol.% industrial waste leather. A PET core was integrated to enhance structural performance. The prepared composites were characterized for tensile, flexural, hardness, impact strength, wear resistance, water absorption, and flammability properties. The results demonstrated significant improvements in the performance of the
composites. Specimen VLG2, containing 3 vol.% GFRP filler, exhibited superior
mechanical properties, including a tensile strength of 135 MPa, flexural strength of
155 MPa, Shore-D hardness of 83, and Izod impact strength of 6.4 J. These improvements were ascribed to the filler particles’ ideal distribution, which enhanced the
matrix’s ability to support loads and distribute stress. At a particular wear rate
of 0.012 mm3/Nm, water absorption of 0.47%, and flame propagation speed of
8.14 mm/min, specimen VLG3, which contained 5 vol.% GFRP filler, demonstrated exceptional wear resistance and flammability performance while retaining a
UL-94 V-0 certification. The improved wear resistance was due to the higher GFRP
filler content, which strengthened the composite against abrasion. The slower flame
propagation and absence of flaming drips were attributed to the flame-retardant
properties of GFRP filler and the char-forming ability of tanned leather. SEM analysis revealed that the uniform dispersion of fillers in VLG2 contributed to its superior
mechanical properties, while the agglomeration of fillers in VLG3 did not significantly affect its wear resistance, water absorption, or flame performance. These findings highlight the importance of optimized material selection and microstructural design in developing durable, high-performance composites suitable for applications
in industries such as automotive, aerospace, marine, and construction.