Hybrid Epoxy Composites Based on Tire Waste-Derived Carbon Black and Eggshells With Enhanced Properties and Aging Life in Different Environmental Conditions

Abstract

Chicken eggshells (ChESh), are an unusual type of biomaterial and huge biological waste because of their rapid formation. In addition, carbon black (CBpyr) recycled from tire wastes by pyrolysis is a significant raw material for obtaining valuable products. This study investigated the effects of the hybrid fillers (CBpyr and ChESh) on the composite properties. The hybrid filler mixture was created in different weight ratios and incorporated into the epoxy matrix (ER) at 15-35 wt%. The 25 wt% hybrid filler ratio proved to be the most suitable for enhancing the mechanical properties. The tensile strength was 104, 99, and 77 MPa for hybrid composites (HC) in the CBpyr: ChESh hybrid filler at 1:1, 1:3, and 3:1 wt ratios. A 1:1 hybrid filler wt ratio was more effective in enhancing fire resistance properties, while a 1:3 ratio was better for achieving thermal resistance of unaged HCs. All 25 wt% HCs had higher storage and loss modulus values than ER. The maximum weight gains over 30 days in pure water, seawater, and hydrothermal aging conditions were found to be 0.99-1.4 %, 0.86-1.18 %, and 1.64-2.63 % for ER and HCs. In contrast to the unaged composite, the composite with the hybrid filler at a 1:3 wt ratio (HC(1:3)) exhibited higher tensile strength under these aging conditions. The mechanical properties were most affected by hydrothermal aging. Also, a lower glass transition temperature (Tg) value reduction was found for the aged HC (1:3). This composite is the most resistant to UV rays.