Abstract
By exposing low-density polyethylene to an atmosphere of fuming sulfric acid, sulfonated low-density polyethylenes (SPE) were prepared and the degree of surface sulfonation for treated film was determined as the weight-increase per unit area. Polypyrrole (PPy) films on the surface of SPE were grew using molecular selfassembly process and the properties of PPy/SPE composite films have been investigated. Then, the functional applications of PPy/SPE composite films have also been proposed and especially the movement properties of actuators using PPy/SPE composite films were mentioned.