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

Abstract

Summary Through the simple precipitation of palygorskite (PGS) by zinc borate (ZB) (to make PGS@ZB) and the decoration of PGS@ZB by dodecylamine (N), a novel organic‐inorganic@inorganic hybrid flame retardant of PGS@ZB‐N was prepared and was incorporated with ethylene vinyl acetate copolymer (EVA) to improve its flame retardance. The structure and morphology of PGS@ZB‐N were characterized by Fourier transform infrared (FTIR) spectroscopy, X‐ray diffraction (XRD), and scanning electron microscopy (SEM), and it was confirmed that the PGS@ZB‐N hybrid had been successfully prepared. The flame retardancy and burning behavior of EVA/PGS@ZB‐N/EG (EG = expandable graphite) composite were studied through thermogravimetric analysis (TGA), limiting oxygen index (LOI), UL‐94 (by the vertical burning test), and cone calorimeter test (CCT) characterizations. The prepared EVA/PGS@ZB‐N/EG composite obtained an LOI value of 41.2% with the addition of 30 wt% PGS@ZB‐N/EG. It was found that EVA/PGS@ZB‐N/EG was protected through a gas phase and condensed phase alternating synergistic effect mechanism.

Flame retardancy effect of phosphorus graphite nanoplatelets on ethylene‐vinyl acetate copolymer: Physical blending versus chemical modification

“…A reasonable yet well‐accepted approach to solve this problem is to incorporate flame‐retardant additives to improve flame retardancy and anti‐dripping properties of EVA 8,12,13 . In recent years, a wide variety of flame retardant additives have been examined in EVA among which are mineral components (zinc borate, 14–18 magnesium hydroxide, 16,19,20 aluminium hydroxide 16,21,22 ), phosphorus‐based materials (red phosphorus, 23,24 ammonium polyphosphate (APP), 7,22,25–27 nitrogen‐based systems (melamine 28,29 ), and carbon‐based flame retardants (expandable graphite [EG], 30–33 graphene nanoplatelets, 34–36 and graphene oxide 30,37 ). Overall, it has been demonstrated that carbon‐based materials such as graphene can change the pyrolysis pathway, dripping, and thermal conductivity in polymer systems 38 .…”