Targeted molecular properties of linear low-density polyethylene (LLDPE)

The idea of polymer reaction engineering (PRE) to link the polymerization process to application properties using the polymer microstructure is used as a base of this work. The focus lies on the control of microstructural properties and short chain branching (SCB) characteristics in polyolefins. To realize the synthesis of sufficient sample amounts of polyolefins with differing SCB- lengths and -densities on polymer backbones of different lengths a mini-plant was built and optimized. Furthermore, a catalytic system capable to produce only short chain branched polymer is described and optimized for the continuous operation mode within the mini-plant. To realize the quantitative correlation estimation in future this study shows first results obtained for a broad variety of -olefins as comonomers analyzed with different analytical methods showing the most suitable comonomers for a deeper investigation. Process parameters and sample handling was optimized to realize homogeneity within the reactor, high catalyst efficiency, full process control and reproducibility of experiments. By this, the mini-plant, the polymerization process conditions, the catalytic system and its handling as well as a choice of promising monomer selection with first conclusions is the result of this work.