Smoke suppressants, analysis

Thermal analysis experiments have clearly shown that tin-based fire retardants markedly alter both the initial pyrolysis and the oxidative burn off stages that occur during polymer breakdown These changes have been interpreted as being indicative of an extensive condensed phase action for the tin additive, in which the thermal breakdown of the polymer is altered to give increased formation of a thermally stable carbonaceous char at the expense of volatile, flammable products. The consequent reduction in the amount of fuel supplied to the flame largely accounts for the beneficial smoke-suppressant properties associated with zinc stannates and other tin-based fire retardants. 

Hassel [103] has compared DSC, TG, thermal evolution analysis, TMA and DMA in evaluating flame retardant textiles based on different polyester fibres. Also the thermoanalytical analysis (DSC, TGA) of a sisal reinforced flame retardant poly-ester/(DBDPO, Sb203) formulation has been described [104]. Larcey et al. [105] have reported use of a simultaneous TG-DSC system (STA) to investigate the suitability of using magnesium hydroxide as a flame retardant and smoke suppressant in PP formulations. 

C in TG-FTIR measurement (792 cm ) of a brominated polystyrene sample [365]. On-the-spot TG-FTIR of PBT/octabromodiphenyl ether (MW 801 Da) detected the brominated diphenylether flame retardant at 275° C and terephthalic acid (the starting monomer of PBT) at 425°C [310]. Similar high-MW species have never been reported in TG-MS experiments the flame retardant was not observed in off-line TG-GC-FTIR-MS analysis. In an examination of an ABS/PC blend with 8% triphenylphosphate (TPP), in addition to the EGP, the SGPs for the specific wavenumber windows of TPP (900-1200 cm ), aromatic compounds (3000-3100 cm ), and carbon oxides originating from PC (2200-2300 cm ), were obtained. TPP evolving first was detected at about 150°C (detection limit 0.5 /xg/s) [310]. Anthony [366] has used FTIR spectroscopy to examine TG residues and diffuse reflectance as the means of sample preparation for the study of interactions between pyromellitate polyesters (smoke suppressants) and polyurethane foams. This was achieved by interrupting the thermal analysis at selected points on the TG curve. In... 

However with poor ventilation they seem to give more persistent smoke than compositions based on ammonium nitrate and sodium chloride. Analysis of the smoke showed it to be due to finely divided ammonium chloride suspended in moist air, and although not harmful it may be objectionable to the miners. In addition, calcium sulphate was included to suppress the smoke (J. Taylor and Gay [4]). Calcium nitrate found only a limited use as a substance for lowering the temperature of detonation flame. 

Robust and reproducible methods have been developed with traditional RP materials for neutral and ion suppressed acidic analytes [51,52], in application to pharmaceutical analysis [34,53,54], aromatic compounds [55], phenols in tobacco smoke [56], preservatives in creams [40,41] nucleosides [57,58] and cannabinoids [59], Typical efficiencies were >100,000 plates/m. The analysis of bases, however, remains a challenge (see later section). The use of other column chemistries such as C8 and phenyl phases allows the selectivity of the stationary phase to be optimised in a similar fashion to that used in LC [60-62], (see Fig. 3.5). 

Landsberger S and Wu D (1995) The impact of heavy metals from environmental tobacco smoke on indoor air quality as determined by Compton suppression neutron activation analysis. Sd Total Environ 173/174 323-337. 

NFPA Health 0. Flammability 1, Reactivi 1 Uses Red Mfg. of phosphoric acid additive to semiconductors fertilizers safely matches pyrotechnics tracer bullets antioxidant and color suppressant for po. coatings flame retardants electroluminescent coatings Wh. Dietary nutrient fertilizers rodenticides smoke screens incendiaries mfg. analytical chemistry gas analysis tracer bullets rat poison... 

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