Molybdenum compounds as flame‐retardants and smoke‐suppressants in halogenated polymers

摘要

AbstractThe hazards resulting rom smoke emission were widely recognized in the early 1970s as a result of several major fire disasters. Since that time considerable interest has been shown in the development of smoke‐suppressants. This paper reviews some of the very promising results that have been obtained using molybdenuem comounds as flame‐retardants and smoke‐suppressantes in halogenated polymers. They have been shown to be effective in both rigid and flexible grades of PVC. In the rigid grades these compounds can reduce smoke emission by at least 80. Reductions in excess of 50 have been observed with typical plasticized formulations, although the magnitude of the effect here depends on both the type and level of plasticizer. Comparisons of the results of different smoke tests suggest that the small‐scale tests commonly used do not fully reflect the true extent of the smoke‐reductions that are obtainable with these combounds. Significant reductions in smoke‐emission have also been obtained with halogenated polyester thermosets and chlorinated elastomer formulations. With the polyesters some of the best results occurred when molybdenum oxide was used in conjunction with alumunium trihydrate. In all cases these compounds proved to have significant flame‐retardant properties. Reference has been made in the paper to their mode of activity but the actual mechanistic investigations have not been discus