AbstractThe surface tension of molten LDPE can be determined with the help of the pendent drop method, depending on the temperature and on the surfactant added. The critical micelle concentration was reached on addition of 1% of the surfactant. A four‐component mixture consisting of HDPE, LDPE, PVC, and PS, whose composition corresponded to that of collected waste plastics, was used to study the effects of the addition of surfactants on the applicational propertie