Absorption spectra in the detection of chemical changes in cellulose and cellulose derivatives

T he spectral absorption of th in fi lms of cellulose a ce tate, 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 w it h periodic acid foll owed by chlor ous aci d, a re recorded fo r the infra red from 2 to 15 mi Cl'O ns and the ultraviolet from 215 to 400 millimicrons.T he rege nerated cellulose absor bed ul t raviolet radia nt e n e rg ~' only a t t he short wavelengt h end of t he region studied , and t he re the t ra nsmi ttan ce of a fi lm 2.8 micon s thick was onl y sli gh tly red uced .The aceta te and oxidized cell uloses abso rbed in this region t o a g reater exten t but gave no narro w absorpti on ban d .~1a rk e rl changes we re obse rved in so me of t he absorpt io n bands in th e infra red region in going fro m cellulose acetate to rege nerated cellul ose an d t o t heir oxidation products.These changes we re co rrelate d 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;;en t by spect ra l a bso rption m ea sil re ments.