Synergistic effects of aluminum hydroxide, red phosphorus, and expandable graphite on the flame retardancy and thermal stability of polyethylene

Abstract

The flame‐retardant low‐density polyethylene (LDPE) composites loading aluminum hydroxide (ATH), red phosphorus (RP), and expandable graphite (EG) were successfully prepared. The flame retardancy, the thermo‐oxidative stability, and the mechanical property of the composites were investigated. The synergistic effect of ATH, RP, and EG on the flame‐retardant property and thermal behavior of LDPE were observed. The limiting oxygen index value of LDPE significantly increased from 17.1% to 25.4% upon the incorporation of 15 wt.% of the mixture of three fillers with ATH:RP:EG mass ratio of 1:1:1; and this composite achieved the V‐0 classification of the UL94 vertical burning test. The thermogravimetric analysis of this composite under air atmosphere revealed that its residue weight remained 27.89% at 900°C. Furthermore, the results of tension tests indicated that the surface modification of ATH by magnesium stearate and RP by poly(methylhydrosiloxane) noticeably improved the tensile strength and the elongation of the composite.

Mechanisms of the Action of Fire-Retardants on Reducing the Flammability of Certain Classes of Polymers and Glass-Reinforced Plastics Based on the Study of Their Combustion

“…Similar results were also obtained for LDPE composites loading aluminum hydroxide (ATH), RP, and expandable graphite (EG) [ 36 ]. The LOI value of LDPE significantly increased from 17.1% to 25.4% upon the incorporation of a 15 wt.% mixture of three fillers with an ATH:RP:EG mass ratio of 1:1:1; this composite achieved the V-0 classification of the UL94 vertical burning test.…”

The potential use of natural expanded perlite as a flame retardant additive for acrylonitrile‐butadiene‐styrene based composites

“…To classify the burning characteristics of polymeric materials, the flame duration and the dripping property of the material during combustion are recorded in the UL-94 test. 64 As expected, the substantially flammable neat ABS failed to receive any rating in the UL-94 test due to the fast burning and severe melt dripping phenomenon. It is clearly observed from Table 3 that the flammability of ABS was greatly improved with the incorporation of EP and UL-94 V-1 fire rating was achieved without any melt dripping and all the composites kept their UL-94 V-1 rating with the increment of EP amount.…”

Flame retardant phosphonate-functionalised polyethylenes

“…LDPE was employed in this study due to its application as a protective jacket for wires and cables. 30 However, LDPE is a highly flammable thermoplastic with melt dripping behaviour when burning.…”

“…However, high loading of ATH of at least 35 wt% is required leading to degraded physical properties (increasing part density and brittleness). Therefore, synergistic flame retardant from the combination of low loading of ATH with phosphorus, 30,32 silicon, 32 e ,33 nitrogen 32 e ,34 or boron 35 containing flame retardant has been extensively studied.…”