Study On The Relationship Between The Architecture And Viscoelasticity Of Metallocene Polyethylene And Their Alloys

The structure and viscoelasticity of metallocene polyethylenes (mPE) and their alloys were studied systematically based on three kinds of common PE and six kinds of mPE. Some important conclusions were obtained:Firstly, the molecular architectures such as molecular weight and its distribution, chain branches and so on were studied by means of a series of modern analysis technologies such as GPC, FITR, 13C NMR etc. It was found that the molecular distribution of mPE was narrower than common PE and the branch structure of mPE was also quite different, among which both mPE-2 and mPE-3 had long branches.Secondly, the shear and elongation rheology of mPE were studied deeply by means of ARES rheometer, RME rheometer, and MFR equipment etc. It was found that the dependence of viscosity of mPE on shear rate was poor, and the shear rheology, elongation rheology and processiblity of mPE could be improved obiviously by introducing long branches into the chain structure of mPE.Finally, the viscoelasticity of alloys of mPE and LDPE were studied in terms of ARES rheometer, RME rheometer, and MFR equipment etc. It was found that not only the shear viscosity of mPE was declined, but also the dependence of its shear viscosity on shear rate and temperature, its elongation rheology and processibility were improved obviously after blending some LDPE with mPE.The results and conclusions obtained provide important data and theoretical support for the study, development and application of mPE.