PGS@B–N: an efficient flame retardant to improve simultaneously the interfacial interaction and the flame retardancy of EVA

Abstract

A novel organic-inorganic hybrid flame retardant of PGS@B-N prepared via the decoration of palygorskite (PGS) by boric acid (B) and dodecylamine (N) was incorporated with ethylene-vinyl acetate copolymer (EVA) to improve its flame retardance. The structure and morphology of PGS@B-N were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The flame retardance and burning behavior of EVA/PGS@B-N/EG (expandable graphite) composite were studied through thermogravimetric analysis (TGA), limiting oxygen index (LOI), vertical burning test (UL-94), and cone calorimeter test (CCT). Results of UL-94 and LOI tests indicated that the flame retardance of EVA/PGS@B-N/EG was better than EVA/PGS/EG flame-retardant composites.heat release rate (PHRR) of EVA with the addition of 30 wt% PGS@B-N/EG was reduced about 25% comparing with EVA with equivalent PGS/EG. The heat release rate (HRR), total release rate (THR), smoke production rate (SPR), and mass loss rate (MLR) of the composite were improved significantly. The TGA data gave that the thermal stability of EVA/PGS@B-N/EG was also well improved at high temperatures.SEM images of cryogenically fractured surfaces illustrated that EVA/PGS@B-N/EG had better interfacial interaction comparing with those of EVA/PGS/EG.

A facile method for preparation of PGS@ZB‐N and gas‐sol alternating synergistic effect for fire resistance of EVA

“…From Figure A, we can see that the major thermal degradation of pure EVA resin involves two stages. The first degradation stage occurred at the interval ranging from 280°C to 390°C, which could be ascribed to the evolution of acetic acid, whereas the second degradation stage finding at the interval ranging from 390°C to 500°C was ascribed to the degradation of polyethylene chains in EVA . As for the EVA/PGS/EG composite, the thermal degradation also involves two stages.…”

“…Figure shows the FTIR spectra of PGS, ZB, and PGS@ZB‐N. In the spectrum of PGS, the band at 3547 and 1653 cm −1 was attributed to O─H stretching vibration . The band at 470 cm −1 was assigned to the coordinate bond of metal ions and oxygen .…”

“…In the spectrum of PGS, the band at 3547 and 1653 cm −1 was attributed to O─H stretching vibration . The band at 470 cm −1 was assigned to the coordinate bond of metal ions and oxygen . The peak at 797 cm −1 may correspond to the stretching vibration of Al─O─Si, and the peak at 1021 cm −1 was attributed to Si─O─Si bonds .…”

“…To now, most research about synergistic effect were focused on the P‐N system; however, there were few attentions paid to the B‐N group . In our previous work, we have combined PGS, boric acid (B), and dodecylamine (N) to construct a flame retardant of PGS@B‐N to improve the flame retardancy of EVA . Herein, a novel organic‐inorganic@inorganic hybrid flame retardant of PGS@ZB‐N with the cooperation element of zinc (Z), comparing with PGS@B‐N, was prepared to investigate the synergistic effect in the EVA/PGS@ZB‐N composites.…”

“…As for other applications of clay‐based materials, sepiolite, montmorillonite, and hydrotalcite can be used as flame retardant to improve flame retardance of the polymers dramatically. As one of the core candidates, the flame retardancy applications of PGS were also well considered . But unsatisfactory compatibility, as well as mechanical performance, limits its applications.…”