Synergistic effects flame retardants

Molybdenum Oxide. Molybdenum compounds incorporated into flexible PVC not only increase flame resistance, but also decrease smoke evolution. In Table 10 the effect of molybdenum oxide on the oxygen index of a flexible PVC containing 50 parts of a plasticizer is compared with antimony oxide. Antimony oxide is the superior synergist for flame retardancy but has Httle or no effect on smoke evolution. However, combinations of molybdenum oxide and antimony oxide may be used to reduce the total inorganic flame-retardant additive package, and obtain improved flame resistance and reduced smoke. 

Of the tin additives studied, the anhydrous and hydrated zinc stannates, ZnSnO and ZnSn(OH), respectively, are considerably more effective flame-retardant synergists with the bromine present in the plastic than 8-stannic acid (Figure 1). In line with this observation, oxidic tin-zinc systems have previously been found to exhibit superior flame-retardant properties to tin oxides alone (19-22). In addition, ZnSnO, gives higher values of 01 than Sb20, incorporation levels studied, and, in fact, the 1% ZnSnO - containing plastics outperform samples containing 2% Sb O,. 

Zinc hydroxystannate and zinc stannate are very effective flame-retardant synergists when incorporated at levels of 1-10% into... 

Certain inorganic tin compounds are effective flame-retardant synergists when incorporated at a 2.5% level into a 50% ATH-filled ethylene-acrylic rubber composition. Tin-containing elastomer formulations retain their flame-retardant superiority at environmental temperatures up to 250°C, and samples containing 2.5% ZnSn(0H)g do not sustain combustion in air at this temperature. 

Chemicals that can yield phosphoric acid during the early stages of fibre pyrolysis form the majority of successful flame retardants for cellulose. However, it is not sufficient to supply just phosphoric acid precursors. The presence of nitrogen has been found to provide a synergistic effect with phosphorous. Minimum levels of added phosphorous and nitrogen for effective flame retardancy have been estimated at 2 % P and 1 % N. However, these minimum levels can vary greatly depending on fabric construction and test requirements. 

In order to attain an effective flame-retardance, alumina trihydrate coupled with a halogenic agent, because of their slight synergism, is recommended. A low amount of zinc borate is also synergistic, but a greater proportion suppresses the effect (Fig. 5.5). 

Mead, N.G. and Brown, S.C. (1993) ATH - An Effective Flame Retardant that also Works Synergistically with Other Products, London, 13/1/1993, Royal Society of Chemistry - Industrial Inorganic Chemicals Group. 

LSFR additive, a proprietary flame retardant synergist, meets the increasing demand for PVC and other polymer products that are not only fire resistant, but smoke resistant as well. Further, LSFR enhances the physical properties of polymers in six additional ways, making it one of the most cost-effective flame retardant additives available. In addition, it offers low specific gravity euid bulk density, and no compromise to your compound s physical integrity. 

Laurel Industries flame retardants are based on Thermoguard antimony-halogen and Pyronil brominated plasticizer technology and used to flame retard a variety of plastics and other materials. Synergistic action occurs when Thermoguard antimony is combined with a halogen which continues to be a very cost effective flame retardant technology for most polymers. 

Flame Retardant Synergist-Antimony oxide in combination with a halogen source constitutes an extremely effective flame retardant for use in broad range of polyaiers. 

It can be seen from Figure 5 that the amount of the added synergist Sb203 of the flame retardant strongly effects the PBDF yield and the optimal temperature of PBDF formation. The kind of polymeric matrix itself does not effect yields of PBDF. 

T. Handa, T. Nagashima and N. Ebihara, Synergistic Action of Sb2(>3 with Bromine-Containing Flame Retardants in Polyolefins. II. Structure-Effect Relationships in Flame Retardant Systems," J. of Fire Retardant Chemistry,, 37 (1981). ... 

Synergistic flame retardants such as a mixture of antimony trioxide and an organic bromo compound are more effective that single flame retardants. Thus, mixtures are often employed to protect materials and people. 

The traditional flame retardant is based on organobromine compounds together with antimony trioxide as a synergist. Magnesium hydroxide is a good flame retardant due to its high decomposition temperature and smoke suppression properties. It is widely used in thermoplastic materials. However, magnesium hydroxide must be added in portions of some 60% to achieve a reasonable effect. 

M. Brebu, E. Jakab, and Y. Sakata, Effect of flame retardants and Sb2C>3 synergist on the thermal decomposition of high-impact polystyrene and on its debromination by ammonia treatment, J. Anal. Appl. Pyrolysis, 79(l-2) 346-352, May 2007. 

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