Polymer Combustion and New Flame Retardants.

摘要

The combustion of polymers is a complex coupled process characterized by energy feedback from a flame to the polymer surface and subsequent gasification of the polymer to generate combustible degradation products. Energy feedback characteristics for two different burning configurations, pool burning and vertical wall burning, are discussed. Thermal degradation of polymers and heat transfer in polymer samples are briefly discussed in order to determine polymer gasification rates at specified external heat fluxes. Transient burning rates of two polymeric materials, PMMA and Douglas Fir, are calculated in a pool flame configuration for two different diameters and the predicted results are compared with the experimental data. A similar comparison is made for upward flame spread in the corner of a room. To improve the fire performance of polymers, use of a nonhalogenated char-forming flame retardant is suggested, and its benefits are discussed. The fire performance of a newly developed char forming flame retardant additive combination in a variety of polymers is described. Although its flame retardant mechanism has been studied by analyzing the char structure in the presence of the additives using solid-state NMR, at present it is not clearly understood.