Composites flame retardant properties

In general, tin compounds do not exhibit flame-retardant properties in halogen-free polymer systems, unless the composition contains a high inorganic filler loading. However, tin additives often act as smoke suppressants in non-halogenated polymers. 

Green J (1989) Flame retardants and smoke suppressants. In Katz HS, MUewski JV (eds) Handbook of fiUers for plastics. Van Nostrand, New York, chapter 4, p93 Hornsby PR, Watson CL (1986) Plast Rubber Process Appl 6 169 Rothon RN (1995) Effects of particulate fiUers on flame retardant properties of polymers. In Rothon RN (ed) Particulate-fiUed polymer composites. Longman, Harlow, Chap 6,p207... 

S. Chang, T. Xie, and G. Yang, Effects of polystyrene-encapsulated magnesium hydroxide on rheological and flame-retarding properties of HIPS composites, Polym. Degrad. Stab., 91(12) 3266-3273, December 2006. 

Rothon, R., Effects of particulate fillers on flame retardant properties of composites, in Particulate-Filled Polymer Composites, 2nd edn., Rothon, R.N. (Ed.), Rapra Technology Ltd., Shawbury, U.K., 2003, Chapter 6, p. 271. 

In an attempt to provide compatibility between the FR and polymer matrix, Wang et al. reported recently on a novel microencapsulated intumescent system containing 4A zeolite as a potential flame retardant for natural rubber (NR).61 The flame-retardant properties of NR composites loaded with different amounts of intumescent flame retardant (IFR), IFR-4A zeolite, and microencapsulated intumescent flame retardant (MIFR)-4A zeolite agents were studied and compared. The LOI data demonstrate that the NR composite filled with 50phr of MIFR-4A zeolite agent and 50phr of IFR-4A zeolite shows better FR properties as compared to NR and 50phr of IFR-filled systems. 

Special considerations cobalt salts reduce UV and thermal stability steel fiber and acrylic fiber give the best wear retention to brake pads composites containing graphite have much better flame retarding properties than composites containing aramid or glass fiber glass fiber slows down the cure rates of novolac resins ... 

Han Z, Diao C, Doug L, Zhang X. Effect of surface-treated nanosilica on thermal behavior and flame retardant properties of EVA/ATH composites. International Conference on Solid Dielectrics. July 2007. 

When a PA is to be used in applications requiring self-extinguishing characteristics and flame retardant properties, it is necessary to resort to the addition of a flame retardant. Flame retardant formulations, known in the field of poly(ester)s, can be widely adapted to PAs. Brominated poly(styr-ene) in combination with an antimony compound, such as sodium antimon-ate, can be used." The performance is improved when a minor amount of calcium oxide is added. The thermal stability of these compositions is much better in comparison to formulations with magnesium oxide or zinc oxide. 

Cai, Y Wei, Q. Huang, R Lin, S. Chen, F. Gao, W. Thermal stability, latent heat and flame retardant properties of the thermal energy storage phase change materials based on paraffin/high density polyethylene composites. Renew Energ 34 (2009) 2117-2123. 

Specific fillers may be added to add or enhance specific properties in magnetic materials. Alumina, antimony trioxide or magnesium carbonate may be added to improve the flame retardant properties of the composite. The addition of lead oxide or carbide lead is suggested for improve resistance to nuclear radiation. To improve thermal conductivity, alumina, aluminium powder or silicates can be added. Silica, talc, mica or kaolin are indicated to increase the electrical resistance. The inclusion of metal powders, metal oxides or silicates are suggested to thermal absorption improvement. To increase the tensile strength in NR-based materials, carbon black in general, fibres or polymeric materials may be added. 

Depending on the distribution of micro/nanofiller in the polymer matrix, the composites may be classified as microcomposites or nanocomposites. These two types of composites differ significantly with respect to their properties. The nanocomposites show improved properties compared to pure polymer or that of microcomposites. It started only back in 1990, when Toyota research group showed that the use of montmorillonite can improve the mechanical, thermal, and flame retardant properties of polymeric materials without hampering the optical translucency behaviour of the matrix. Since then, the majority of research has been focused in improving the physicochemical properties, e.g. mechanical, thermal, electrical, barrier etc. properties of polymer nanocomposites using cost effective and environmental friendly nanofillers with the aim of extending the applications of these materials in automotive, aerospace, construction, electronic, etc. as well as their day to day life use. The improvements in the majority of their properties have invariably been attributed... 

Murariu, M., Bonnaud, L., Yoann, P., Fontaine, G., Bouibigot, S., Dubois, P. New trends in polylactide (PLA)-based materials "Green PLA-Calcium sulfate (nano) composites tailored with flame retardant properties. Polym. Degrad. Stab. 95, 374—381 (2010)... 

C.M. Becker, A.D. Gabbardo, P. Wypych, S.C. Amico, Mechanical and flame-retardant properties of epoxy/Mg-Al LDH composites. Composites Part A Applied Science and Manufacturing, ISSN 1359-835X 42 (2) (February 2011) 196-202. http //dx.doi. org/10.1016/j.compositesa.2010.11.005. 

For this reason, HMTA cured novolac networks are generally brittle in nature and have low fracture energies and impact strengths, probably due to the voids combined with the high crossliiik densities. Curing novolac resins with epoxy resins can produce networks without volatile by products. These can be reinforced with glass or carbon fibers to yield tough, void-fiee composites, which also retain much of the flame-retardant properties of phenolics [39],... 

For instance, the effect of smoke reduction and flammability performance of zinc-based compounds (i.e. zinc borate and zinc hydroxystannate) in epoxy resin composites used in the aerospace and aeronautical industries have been analyzed (Formicola et al., 2011). The flammability performance of neat and loaded systems was analyzed by using micro-combustion calorimetry, while smoke generation, in terms of CO and CO2 production, was analyzed under dynamic conditions by using cone calorimetry. The experimental results have shown that the dispersion of zinc borate and zinc hydroxystannate within epoxy matrices leads to a significant variation in flame retardant properties in particular the total heat release is reduced by about 25% and 30%, respectively, and the heat release capacity by about 30% and 50%, respectively. The system containing zinc hydroxystannate shows an enhancement in all smoke reduction properties, and both compounds lead to a reduction of the CO2/CO ratio. 

Effects of Particulate Fillers on Flame Retardant Properties of Composites... 

---