Ultraviolet-visible spectroscopy carbonyl groups

The dichroic ratio can also be measured using ultraviolet or visible radiation (UV-visible spectroscopy). Polymers with carbonyl groups, phenyl groups and other conjugated systems may be studied. 

Ultraviolet and visible light absorption spectroscopy can be used to identify chromophores (e.g. benzene rings and carbonyl groups) and to determine the lengths of sequences of conjugated multiple bonds in polymers. It also can be used to analyse polymers for the presence of additives such as antioxidants or for detection of residual monomer(s). Additionally, fluorescence and phosphorescence techniques are important in studies of polymer photophysics. 

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