5.1 Ethyl acrylate is copolymerized with ethylene to produce film, molding, and wire coating resins with improved physical properties. Ethyl acrylate comonomer increases flexibility, stress cracking resistance, toughness, and clarity. A rapid quantitative technique is needed for the evaluation of the amount of ethyl acrylate in a resin for specification purposes because physical properties change rapidly with increasing comonomer content.

5.2 Infrared spectrophotometric analysis, when suitably calibrated, can be used for the measurement of the concentration of comonomer present. Calibration is performed with samples that have been analyzed for oxygen content by fast neutron activation analysis. Oxygen content is converted to ethyl acrylate comonomer content by a simple calculation.

5.3 A purpose of the infrared method of analysis is to provide a procedure for use in quality control analysis. It is a rapid, secondary method of analysis as contrasted with the more expensive and time-consuming fast neutron activation analysis which is the primary, calibrating method.