Sulfonation of low‐density polyethylene films. Infrared absorption coefficients for the sulfonic group

The chemical modification of the surface of low‐density polyethylene films exposed to an atmosphere of fuming sulfuric acid for different periods of time has been investigated. The degree of surface sulfonation for each treated film was calculated as the weight‐increase per unit area. The correlation of the absorbance of infrared bands associated to the sulfonic group with the degree of sulfonation of the films allowed to determine the IR absorption coefficients, especially for the band at 1 040 cm −1 .