Synthesis and characterization of fiber-reinforced lightweight foamed phosphogypsum-based composite

A foamed phosphogypsum-based composite (FPGC) was synthesized in this study via chemical foaming and the effect of hydrogen peroxide (H2O2) (0.5% to 2.5%) on its properties was investigated. With the increasing dosage of H2O2, more foamed pores were produced, causing a decline in the mechanical strength and water resistance of mixtures. Nonetheless, the increased pores resulted in an improvement in thermal insulation and acoustic ab-sorption. Fiber addition resulted in slight enhancement in the acoustic absorption and thermal conductivity but significantly improved the mechanical strength and water resistance of fiber-reinforced FPGC, particularly polyvinyl alcohol (PVA) fiber. The calcium stearate (CS) (5% to 25%) as foam stabilizer was also incorporated to ascertain its effect on the properties of FPGC. CS content exceeding 15% had a positive effect on the properties of fiber-reinforced FPGC. Finally, the fiber-reinforced FPGC with 1% PVA fiber, 1.5% H2O2, and 20% CS attained a bulk density of 826 kg/m3, compressive strength of 5.08 MPa, softening coefficient of 0.69, and improved sound absorption and thermal conductivity of 0.483, and 0.221 W/m & BULL;K, respectively. This study presents a promising approach for the utilization of phosphogypsum (PG), and further works can be explored to evaluate the long-term performance and durability of FPGC in various environmental conditions.