Research On High-Melt-Strength Polypropylene With Long-Chain-Branching Structure (LCB-HMSPP) Prepared By ～(60)Co-γ Irradiation: Rheological Properties And Applications In Extrusion Foaming

This paper dear with the preparation, rheological properties, as well as extrusion foaming of high-melt-strength polypropylene with long chain branching structure (LCB-HMSPP). LCB-HMSPP was achieved by 60Co-γ ray irradiation in presence of bi-functional monomer. ARES (advanced rheology expended system), capillary rheometer and Gottfert rheotens extensional rheometer were introduced to investigate the shear and extensional rheological behavior of this LCB-HMSPP. In addition, sag resistance, another important parameter to characterize melt strength, was also carried out. Effect of sentilizer content, radiation dose and adding a small amount of high molecular weight component on shear and extensional rheological behavior, such as melt elasticity, die swell, melt flow rate, sag resistance, melt strength and transient extensional viscosity, were intensively discussed. Meanwhile, mechanism of forming the long chain branching structure of PP during high energy irradiation was proposed.As evidenced by ARES, capillary rheometer, sag resistance and rheotens...