Distribution analysis of carbonyl groups in a polymer by derivatization/electron probe X-ray micro-analysis

An analytic method, referred to as "derivatization/electron probe X-ray micro-analysis (EPMA)", has been developed to determine the distribution of a small amount of carbonyl groups formed by the oxidation of polymers by chemical derivatization with 2,4,6-trichlorophenylhydrazine (TCPH). A suitable condition of the derivatization reaction with carbonyl groups in polymers was investigated. It was found that the highest reaction yield and selectivity were obtained by heating the sample in a 2.5% TCPH/acetic acid solution at 90 degrees C for 30 min. Acetic acid was used as a catalyst and a solvent. By derivatization/EPMA using this reaction condition, a distribution measurement of the carbonyl group in the polymer became possible in 0.01% of the detection limits. Actual applications to a depth analysis of degraded ethylene-carbon mono oxide copolymer and polyethylene proved that this method is useful for the characterization of polymers and studies on polymer degradation.