Polyamides, aliphatic Nylon 6 copolymer

Aliphatic esters absorb light at rather shorter wavelengths than the ketone copolymers and, hke PMMA, are regarded as having good photostability. Aliphatic polyamides are much less photostable and nylons degrade in outdoor exposure by a combination of photocleavage and photo-oxidation (116-118). 

STRUCTURE As described in several articles md patents/ this type of aromatic nylon resin is a polyamide consisting of varying portions of aliphatic and aromatic units. Hexamethylene diamine is the main aliphatic component, which may be augmented by various amounts of adipic acid. The main aromatic component is terephthalic acid, which may be augmented by lesser amounts of isophthalic acid. Depending on relative composition, Amodel (nylon 6,6 copolymer) resins can be regarded as co- and terpolymers consisting of repeat units of nylon 66, nylon 6T, and nylon 61 —poly (hexamethylene isophthalamide). The major potential difference of other aromatic nylons, such as Ultramid T from BASF, is the presence of the 61 component. 

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