Properties of blends of linear and branched polypropylenes in film blowing

The effect of blending a long-chain branched polypropylene (LCB-PP) with a linear polypropylene (L-PP) on the processability and properties of blown films was investigated. The rheological data revealed that blending an LCB-PP with an L-PP improved the elongational properties and the bubble stability, but a severe drop in the mechanical strength was observed for the blends. The most deteriorating effect was the reduction in the elongation at break in tensile tests carried out in the transverse direction (TD), where no yielding behaviour was observed for the blends.