Synergistic effect of natural zeolites on flame retardant additives

Abstract

The thermal degradation and flammability of intumescent fire-retardant polypropylene matrix composites consisting of ammonium polyphosphate (APP) as an acid source and blowing agent, pentaerythritol (PER) as a carbonisation agent and natural zeolite (clinoptilolite rich, Go¨rdes II) as a synergistic agent were examined. APP and PER combinations were examined at different ratios (0.25, 0.33, 0.5, 1, 2, 3, and 4) for optimisation of the formulation for flame retardancy. The zeolite was incorporated into flame retardant formulation at four different concentrations (1, 2, 5, and 10 wt%) to investigate the synergism between the flame retardant materials. The thermal degradation and flammability of composites were characterized by thermogravimetric analysis (TGA) and by limiting oxygen index (LOI) measurement and horizontal burning (HB) tests. A synergistic effect in flame retardancy was observed when natural zeolites were used in combination with APP and PER.

Optimisation of the effect of colemanite as a new synergistic agent in an intumescent system

“…In the literature, APP/PER/natural and synthetic zeolite intumescent systems in PP are studied and it is stated that intumescent material should be around 30 wt% to obtain satisfactory improvements in flame retardancy and the rest should be PP [17]. Therefore concentration of PP was kept constant at 70 wt% in the experimental design procedure.…”

Synergistic effects of sepiolite on intumescent flame retardant polypropylene

“…In order to enhance the flame retardancy, new intumescent flame retardant systems have been developed rapidly [3,[6][7][8], which has high flame retardant efficiency. In addition, some synergistic agents have also been used to improve further the flame retardant of intumescent flame retardant PP systems, such as nano-Mn 0.4 Zn 0.6 Fe 2 O 4 [9], zeolites [10], montmorillonite [11,12], silica [13], alumina [13], silicotungstic acid [14], lanthanum oxide [15,16], nano-BaWO 4 [17], expandable graphite [18], iron powder [19], nanoflaky manganese phosphate [20], phosphotungstic acid [21], hydroxy silicone oil [22], a-ZrP [23], colemanite [24], zinc borate [25], polysilsesquioxane [26], borosiloxane [27] and other metallic compounds [1]. Sepiolite is a family of fibrous hydrated magnesium silicate with the theoretical half unit-cell formula Si 12 O 30 Mg 8 (OH) 4 (OH 2 ) 4 ·8H 2 O characterized by a needle-like morphology [28].…”

Mechanism of enhancement of intumescent fire retardancy by metal acetates in polypropylene

“…The ratio of APP and PER was set to 3:1, which generally gives the best fire retardancy performance for APP and PER combinations [18] . PP composites were compounded at 185…”