Absorption Spectra in the Detection of Chemical Changes in Cellulose and Cellulose Derivatives

The spectral absorption of th in fi lms of cellulose acetate, regenerated cellulose, t he a ce tate and regenerated cellulose after oxid ation with nitrogen d ioxide gas, a nd t he regenerated cell ulose after oxida tion with periodic acid followed by chlorous aci d, a re recorded fo r the infra red from 2 to 15 mi Cl'Ons and the ultraviolet from 215 to 400 mill imicrons. T he regenerated cellu lose absorbed ul t raviolet radiant en erg~' only a t t he short wavelengt h end of t he region studied , and t he re the t ra nsmi ttance of a fi lm 2.8 micon s thick was only sli gh tly red uced . The aceta te and oxidized cell uloses absorbed in this region t o a g reater exten t but gave no narrow absorpti on band . ~1arkerl changes were observed in some of t he absorpt ion bands in th e infra red region in going from cellulose acetate to regenerated cellulose an d t o t heir oxidation products. These changes were co rrelated wi th changes in t he OR. CO,' and COOH g roups. T he r ul ts indi ca te t he possibilit .'· of es ti mating t he a mount of th ese group s pre;;ent by spect ra l abso rption