简 介: |
Polypropylene (PP) is a fast growing commodity resin as it possesses many beneficial properties such as low density, high stiffness, good resistance to chemicals, and an easy processability. The conventional PP consists of linear molecules, the molar mass of which can be varied in a wide range resulting in different flow properties. Introducing long-chain branches (LCB) adds particular rheological properties to the material which are advantageous for processing operations like thermoforming or foaming. Special rheological measurements can be used to assess the behaviour of PP with respect to these applications which are dominated by elongational flow. Moreover, rheological experiments are a powerful tool to get an insight into the molecular structure of polypropylenes, particularly, in the case of long-chain branching. |