Improved ceramifiable properties of EVA composites with whitened and capsulized red phosphorus (WCRP)

Abstract

Ceramifiable EVA composites were prepared by addition of WCRP and silicate glass frits (SGFs) to EVA resin. Ceramic residues were obtained by firing ceramifying EVA composites at 600, 800 and 1000 °C for 30 min. The effect of WCRP on the self-supporting property of the composites and the effect of firing temperatures on the flexural strength of the ceramic residues for the composites are investigated. Results show that the addition of WCRP improves the self-supporting property of the composites, and the flexural strength of the ceramic residues containing phosphorus is enhanced with increasing temperature. XRD analysis shows that addition of WCRP promotes the precipitation of cristobalite (SiO₂), which leads to an improvement in the properties. XRF and FT-IR demonstrate the WCRP in the composite could be converted into [PO₄]³⁻ at high temperature. It can be concluded that phase separation between the phosphates and SGFs causes the formation of the crystalline phase. SEM confirms that the number of pores in the residues decreases with increasing temperature, which results in the increase in flexural strength.