Polypropylene Blends for Highly Drawn Tapes with Improved Toughness.

In this study, we used four amorphous poly-alpha-olefin (APAO) grades to improve the toughness of drawn polypropylene (PP) tapes. The samples containing different amounts of APAOs were drawn in a heat chamber of a tensile testing machine. The APAOs reduced the work of drawing and increased the melting enthalpy of the drawn specimens, as they facilitated the movement of the PP molecules. The APAO with the highest molecular weight and with a low level of crystallinity increased both the tensile strength and the strain-at-break of the specimens, so we also produced drawn tapes from that PP/APAO blend on a continuous-operation stretching line. The continuously drawn tapes also showed improved toughness.