摘要:

AbstractAn investigation of the burning behaviour of a series of halogenated polyester resin formulations has been carried out using the Cone Calorimeter technique. The data obtained clearly indicate that zinc hydroxystannate (ZHS) is more effective than antimony trioxide (Sb2O3) in reducing the average and peak rates of heat release in a chlorinated resin and in decreasing the peak rate of heat release in a brominated resin. The decreases in average heat release rate in the brominated resin are similar for ZHS and Sb2O3. Hence, at an addition level of 2 phr (parts per hundred of resin), ZHS reduces the average heat release rates of a chlorinated and a brominated resin by 41% and 26%, respectively, and the peak heat release rates of the same resins by 38% and 39%, respectively. The degree of smoke suppression exhibited by ZHS in these Cone experiments is significantly greater than that given by Sb2O3. In general, the correlation between Cone Calorimeter data and results obtained using other laboratory fire tests (UL‐94, LOI) is poor, except in the case of smoke density measurements, where the correlation with NBS Smoke Box data is remarkably good. No correlation is observed between the measured values of CO and CO2output by different test methods, although it is now generally considered that small‐scale fire tests cannot be used to predict gaseous concentrations in real‐fire situa

ISSN:0308-0501    

DOI:10.1002/fam.810170102

出版商:John Wiley&Sons Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractFour wire coating materials (two of them based on PVC and the two others based on XLPE) were assessed for the irritancy of their smoke, under non‐flaming conditions, by using the respiratory depression method, expressed as theRD50. The DIN 53 436 combustion tube was used as the fire model, at a temperature of 550°C (smouldering mode), and the animal model was the mouse. Animals were exposed for 10 min, at concentrations too low to cause lethality. It was found that there was relatively little difference between the irritancy of all four smokes. This was an unexpected result, since it had been predicted that PVC smoke would be much more irritating than XLPE smoke. In fact, the smoke from the PVC compounds had anRD50roughly in the range of 100–1000 ppm, while the smoke from the XLPE compounds had anRD50roughly in the range of 10–100 ppm. This means that PVC smoke is somewhat less irritating than XLPE smoke. The components in the smoke of all materials were determined by a combination of continuous gas analysis, ion chromatography and gas chromatography/mass spectrometry, with the objective of understanding the factors causing the irritancy. Hydrogen chloride, one of the major decomposition products of PVC, is also the most important smoke constituent causing irritancy of the smoke. Its irritancy, however, was insufficient, by a considerable margin, to explain the full degree of irritancy found. TheRD50of HCl is, like that of PVC smoke, in the range of 100–1000 ppm. On the other hand, the only compound found in the smoke of XLPE compounds with anRD50in the same 10–100 ppm range as he overall smoke is methyl vinyl ketone. Unfortunately, the concentration of methyl vinyl ketone was much too low to account for the irritancy levels encountered. Literature data indicate that polyethylene smoke is rich in long‐lived free radicals and that PVC smoke does not contain them. Moreover, such free radicals are associated with various illnesses, particularly with respiratory symptoms. Thus, it is speculated that such free radicals could be the cause of the high irritancy of the smoke from the XLPE wire coati

ISSN:0308-0501    

DOI:10.1002/fam.810170103

出版商:John Wiley&Sons Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractA series of cellulose–polysilicic acid hybrid fibres with 15–35% silica contents were spun and their flammabilities were assessed by the LOI oxygen index test. Also, the rate of heat release and toxicities of fumes evolved during the combustion process for hybrid fibre with 33% SiO2loading was obtained using the cone calorimeter and FT‐IR techniques. The low flammability and toxicity indices indicate that this hybrid fibre can be used as a flame‐retardan

ISSN:0308-0501    

DOI:10.1002/fam.810170104

出版商:John Wiley&Sons Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractThree timber‐based materials were investigated by subjecting them to a constant uniform heat flux in the range 20–70 kW m−2using a Cone Calorimeter and the ISO Ignitability Apparatus. The specimens were examined in the vertical and horizontal orientations in the Cone Calorimeter using gas flame pilot, spark pilot and spontaneous methods of ignition. They were also studied using the ISO Ignitability Apparatus in the normal and inverted horizontal orientations using gas flame pilot and spontaneous methods of ignition. The results obtained are compared by specimen, orientation and mode of ign

ISSN:0308-0501    

DOI:10.1002/fam.810170105

出版商:John Wiley&Sons Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractThe pyrolysis of benzonitrile under nitrogen at atmospheric pressure has been studied at temperatures of 823–873 K in a flow reactor. The results demonstrate that conversion to hydrogen cyanide occurs directly by a free radical mechanism. The dominant products detected are hydrogen cyanide, monocyanodiphenyl, benzene, dicyanodiphenyl and dicyanobenzene. Reaction orders and activation energies have been determined for product formation. A reaction scheme involving three competing chain reactions in the gas phase with chain carriers H., C6H 5.and.C6H4CN is proposed to explain the observed kinetics. A mechanism is advanced for the formation of significant quantities of polymer, consistent with infra‐red spectra and elemental ana

ISSN:0308-0501    

DOI:10.1002/fam.810170106

出版商:John Wiley&Sons Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractThe Superphosphate Fertilizer, to be referred to simply as fertilizer, was used to impregnate some tropical timbers. It was observed that this treatment drastically altered the thermal characteristics of these materials. The results are interpreted as arising from the fact that on heating, fertilizer evolves molecules that interfere with the chemistry of pyrolysis/combustion of wood cellulose.

ISSN:0308-0501    

DOI:10.1002/fam.810170107

出版商:John Wiley&Sons Ltd.    

年代:1993

数据来源: WILEY

摘要:

AbstractThe Cone Calorimeter has been used for fire testing of different products on a small scale for almost a decade. However, the number of users has been increasing in the last two to three years. More experimentation with the apparatus has led to practical questions. One of these is about the use of a retainer frame which has been used mainly for building products, but very few direct comparisons have been presented.

ISSN:0308-0501    

DOI:10.1002/fam.810170108

出版商:John Wiley&Sons Ltd.    

年代:1993

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810170109

出版商:John Wiley&Sons Ltd.    

年代:1993

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810170110

出版商:John Wiley&Sons Ltd.    

年代:1993

数据来源: WILEY

ISSN:0308-0501    

DOI:10.1002/fam.810170101

出版商:John Wiley&Sons Ltd.    

年代:1993

数据来源: WILEY