Ultraviolet radiation, nylon

Acrylamide readily undergoes polymerization by conventional free radical methods, ionizing radiation, ultrasonic waves, and ultraviolet radiation. The base-cata-lized hydrogen transfer polymerization of acrylamide yields poly-/3-alanine (Nylon 3) a water insoluble polymer that is soluble in certain hot organics. All current industrial production is believed to be by free radical polymerization. 

However, Jellinek and Chaudhuri exposed Nylon 66 films to nitrogen dioxide, ozone, and ultraviolet radiation. The degree of degradation of polymer a was measured by... 

Jellinek, H. H. G., and A. K. Chaudhuri. Inhibited degradation of nylon 66 in presence of nitrogen dioxide, ozone, air, and near-ultraviolet radiation. J. Polymer Sci. Part A-1. 10 1773-1778, 1972. 

Another reason for an apparent, but not a true, limit to the amount of a particular product formed would be the existence of competing reactions such as chain breaking and cross-linking. Charlesby has developed equations to permit calculation of the ratio of chain breaking to cross-linking in thermoplastic polymers exposed to high energy radiation (29). These have been applied to analyze the effect of exposure of Acrylan, Mylar, nylon and polyethylene to 2537 A ultraviolet radiation (30). 

Ultraviolet radiation Polyolefins, nylon. Chain scission of surface... 

El-Zaher, N.A., Kishk,S.S. Study of the effect of ultraviolet radiation on the chemical structure, mechanical properties and crystallinity of nylon-6 films, Colourage, 43 (1996) 11, p. 25-30... 

Many polymeric materials serve in applications that require exposure to outdoor conditions. Any resultant degradation is termed weathering, which may be a combination of several different processes. Under these conditions, deterioration is primarily a result of oxidation, which is initiated by ultraviolet radiation from the sun. Some polymers, such as nylon and cellulose, are also susceptible to water absorption, which produces a reduction in their hardness and stiffness. Resistance to weathering among the various polymers is quite diverse. The fluorocarbons are virtually inert under these conditions some materials, however, including poly(vinyl chloride) and polystyrene, are susceptible to weathering. 

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