Polypropylene Blends for Highly Drawn Tapes with Improved Toughness

In this study, weused 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 aheat chamber of a tensile testing machine. The APAOs reduced the workof drawing and increased the melting enthalpy of the drawn specimens,as they facilitated the movement of the PP molecules. The APAO withthe highest molecular weight and with a low level of crystallinityincreased both the tensile strength and the strain-at-break of thespecimens, so we also produced drawn tapes from that PP/APAO blendon a continuous-operation stretching line. The continuously drawntapes also showed improved toughness.

Automated summary

In this study, four different grades of amorphous poly-alpha-olefin (APAO) were used to increase the toughness of drawn polypropylene (PP) tapes. The presence of APAOs facilitated the movement of PP molecules, reducing the work of drawing and increasing the melting enthalpy of the drawn specimens. The APAO with the highest molecular weight and low crystallinity level showed the greatest improvement in both tensile strength and strain-at-break, and this blend was used to produce continuously drawn tapes on a stretching line, exhibiting improved toughness.