Thermal stability and flame retardancy of LDPE/EVA blends filled with synthetic hydromagnesite/aluminium hydroxide/montmorillonite and magnesium hydroxide/aluminium hydroxide/montmorillonite mixtures

Ibarra, Laia Haurie; Fernández, A. Inés; Velasco, José Ignácio; Chimenos, J.M.; Cuesta, José‐Marie Lopez; Espiell, F.

doi:10.1016/j.polymdegradstab.2007.02.014

Cited by 127 publications

(60 citation statements)

References 26 publications

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“…Initially it appears that Haurie [84] found contradictory results to Laoutid [85]. Haurie reports that a blend of hydromagnesite with oMMT gives a reduction in LOI, the opposite of Laoutid"s reported increase, however Haurie"s total filler content is not kept constant.…”

Section: Fire Retardant Polymer Nanocomposites Containing Hydromagnesitementioning

confidence: 95%

The fire retardant behaviour of huntite and hydromagnesite – A review

Hollingbery

Hull

2010

Polymer Degradation and Stability

136

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Naturally occurring mixtures of hydromagnesite and huntite have found important industrial use. Their endothermic decomposition over a temperature range similar to that of commonly used polymers and their release of water and carbon dioxide, has led to such mixtures being successfully used as fire retardants. They have replaced aluminium hydroxide and magnesium hydroxide in many applications. The current understanding of the thermal decomposition mechanism of both minerals and their combination in natural mixtures has been reviewed and related to their fire retardant action. Both minerals contribute to the reduction in flammability of polymers although the extent of these interactions has not been fully investigated. However, the fire retardant mechanism of these minerals appears more complicated than either aluminium hydroxide or magnesium hydroxide. This paper critically examines the literature on the fire retardant behaviour of mixtures of hydromagnesite and huntite, providing information of particular use to formulators of fire retardant polymers using these minerals. It also highlights the gaps in understanding of the fire retardant mechanisms of mixtures of hydromagnesite and huntite and areas that require further research.

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Section: Fire Retardant Polymer Nanocomposites Containing Hydromagnesitementioning

confidence: 95%

The fire retardant behaviour of huntite and hydromagnesite – A review

Hollingbery

Hull

2010

Polymer Degradation and Stability

136

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“…Complete pyrolysis of PP from PP/MH composites took place between approximately 400 and 500 °C, similar to PP alone. Several polymer/Mg(OH)2 systems have already been tested where the addition of the filler had no significant influence on the decomposition behavior of the polymer [54][55][56]. A strongly reduced MLR in step two originated from the replacement of matrix polymer PP by a large amount of MH filler.…”

Section: Pyrolysismentioning

confidence: 99%

Flame-Retardancy Properties of Intumescent Ammonium Poly(Phosphate) and Mineral Filler Magnesium Hydroxide in Combination with Graphene

et al. 2014

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Thermally reduced graphite oxide (TRGO), containing only four single carbon layers on average, was combined with ammonium polyphosphate (APP) and magnesium hydroxide (MH), respectively, in polypropylene (PP). The nanoparticle's influence on different flame-retarding systems and possible synergisms in pyrolysis, reaction to small flame, fire behavior and mechanical properties were determined. TRGO has a positive effect on the yield stress, which is decreased by both flame-retardants and acts as a synergist with regard to Young's modulus. The applicability and effects of TRGO as an adjuvant in combination with conventional flame-retardants depends strongly on the particular flame-retardancy mechanism. In the intumescent system, even small concentrations of TRGO change the viscosity of the pyrolysing melt crucially. In case of oxygen index (OI) and UL 94 test, the addition of increasing amounts of TRGO to PP/APP had a negative impact on the oxygen index and the UL 94 classification. Nevertheless, systems with only low amounts (≤1 wt%) of TRGO achieved V-0 classification in the UL 94 test and high oxygen indices (>31 vol%). TRGO strengthens the residue structure of MH and therefore functions as a strong synergist in terms of OI and UL 94 classification (from HB to V-0).

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“…However, the suitability of both synthetic and natural hydromagnesite as a fire retardant for polymers could improve the cost effectiveness of the plan and lead to a future commercial source of hydromagnesite. There has also been interest in the literature [25,[27][28][29][30][31] in synthetic hydromagnesite as a fire retardant.…”

Section: Sources Of Hydromagnesite and Huntitementioning

confidence: 99%

The thermal decomposition of huntite and hydromagnesite—A review

2010

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Naturally occurring mixtures of hydromagnesite and huntite are important industrial minerals. Their endothermic decomposition over a specific temperature range, releasing water and carbon dioxide, has lead to such mixtures being successfully used as fire retardants, often replacing aluminium hydroxide or magnesium hydroxide. The current understanding of the structure and thermal decomposition mechanism of both minerals and their combination in natural mixtures is reviewed. The crystalline structure of both minerals has been fully characterised. The thermal decomposition of huntite has been characterised and is relatively simple. However, the thermal decomposition mechanism of hydromagnesite is sensitive to many factors including rate of heating and the composition of the atmosphere. The partial pressure of carbon dioxide significantly affects the decomposition mechanism of hydromagnesite causing magnesium carbonate to crystallise and decompose at a higher temperature instead of decomposing directly to magnesium oxide.Keywords: hydromagnesite, huntite, fire, flame, retardant, mineral This review critically examines the sometimes conflicting reports in the published literature. It draws together current knowledge of the structure and thermal decomposition of hydromagnesite and huntite, in order to provide an insight into the thermal behaviour of mixtures of these minerals and to optimise their selection and applications. Industrial use of Mineral Fillers as Fire Retardant AdditivesThe largest group of mineral fire retardants are metal hydroxides. Their endothermic decomposition and associated release of inert gasses or water vapour, above the processing temperature but below the thermal decomposition temperature of polymers suppresses the ignition, while the accumulation of a solid inert residue on the surface of the burning polymer reduces the heat release rate. Aluminium hydroxide (ATH) and magnesium hydroxide are the most widely used [1]. Globally aluminium hydroxide is the highest tonnage fire retardant [2,3]. It decomposes according to the following reaction:The endothermic loss of water resulting from the thermal decomposition of ATH has been variously reported [3][4][5] between 1170 and 1300 Jg Magnesium hydroxide is used less widely than ATH. It decomposes through a similar endothermic mechanism to ATH, giving off water. Mg(OH) 2(s) → MgO (s) + H 2 O (g)The endotherm for this reaction is quoted at values between 1244 to 1450 Jg -1 by various authors [3,[5][6][7]. It starts to decompose at about 300 -330°C giving off water [5]. L.A. Hollingbery, T.R. Hull / Thermochimica Acta 509 (2010) 1-112 Although ATH and magnesium hydroxide are the most well known mineral fire retardants, Rothon [5] has identified a number of minerals (Table 1) that could be of potential benefit in polymers. Each decomposes endothermically with the evolution of either carbon dioxide, water or both. Of these minerals, hydromagnesite is the one that has probably seen most commercial interest. Hydromagnesite is naturally occurring...

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Thermal stability and flame retardancy of LDPE/EVA blends filled with synthetic hydromagnesite/aluminium hydroxide/montmorillonite and magnesium hydroxide/aluminium hydroxide/montmorillonite mixtures

Cited by 127 publications

References 26 publications

The fire retardant behaviour of huntite and hydromagnesite – A review

The fire retardant behaviour of huntite and hydromagnesite – A review

Flame-Retardancy Properties of Intumescent Ammonium Poly(Phosphate) and Mineral Filler Magnesium Hydroxide in Combination with Graphene

The thermal decomposition of huntite and hydromagnesite—A review

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