Effect of cast extrusion parameters on the surface properties of films made of polyethylene blends with olefinic ionomers

In critical applications where long-term toughness and ductility are required in the manufactured products, such as pipes for drinking water distribution, polyethylene is the optimal material choice. Pipes for hot water transportation are usually multilayered and polyurethane foam is used to provide thermal insulation. Polyurethane and polyethylene have a high difference in polarity determining a poor interfacial adhesion. To increase the polarity of the compound, blends of polyethylene and a zinc ionomer were produced via twin screw extrusion. The pellets were then used to fabricate films via cast extrusion. The surface properties of the films were modified by varying the drawing roll speed. As the drawing speed of the film increases, an intensified presence of the polar groups on the film surface was observed via FTIR analysis. The mechanical and thermal properties of the produced films and of the compounds were evaluated to ensure the applicability for extrusion pipe manufacturing.