| Abstract:
The Precise prediction of polypropylene synthesized by heterogeneous Ziegler-Natta catalysts needs good knowledge of parameters affecting on polymerization. Molecular weight and molecular weight distribution are among important characteristics of a polymer determining physical-mechanical properties. Broadening of molecular weight distribution is an important and well known characteristic of polypropylene synthesized by heterogeneous Ziegler- Natta catalysts, So it is important to understand the origin of broad molecular weight.
Two main factors in broadening molecular weight, namely mass transfer resistances and multiplicity of active sites, are discussed in this paper and a model including these factors is presented. Then we calculate molecular weight and molecular weight distribution by the model and compare our results with experimental results in open literature. Also the effect of the amount of hydrogen on molecular weight and molecular weight distribution is studied by the model.
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