Protection against intense light. II. The role of the gaseous decomposition products

Abstract

synopsisScreening studies have shown that of a series of halogenated vinyl polymers, poly-(vinylidine fluoride) gives comparatively good thermal protection when exposed to the intense light energy of the carbon arc-image furnace. Results indicate that this protection is undoubtedly provided by polyenes, -(CH=CF),,-, formed during pyrolysis. Decomposition products containing these structures are expelled by the gases formed into the region between the light source and the target where they intercept photons from about 200 to 500 m p and dissipate the energy to the air as heat and/or reradiate it. Instrumental evidence for polyene formation is given. The concept of polyene formation clarifies the relative thermal protection offered by a series of vinyl polymers.