The Study On Polyolefin Nano-composites And New Type Catalysts For Olefin Polymerization

The organic/inorganic nano-composite is a new area with rapid development in polymer material science. The stiffness, dimension-stability and thermal-stability of the inorganic materials and the toughness, processability and dielectric property of the polymers can be combined properly in this new material. Nano-composites open a new horizon of composite materials.Polyethylene/palygorskite nano-composites were prepared successfully for the first time via the "in-situ polymerization method". The methodology of the preparation of this composit was studied systematically. Besides, the structure of the active sites supported on the nano-scale fibers of palygorskite, which initiated the polymerization of ethylene, and the kinetics of ethylene polymerization were investigated in this paper. The results suggest that after appropriate treatment, only a few quantities of active component is needed to be supported on the palygorskite, and it can initiate the ethylene polymerization with high efficient.The structure and properties of the polyethylene/palygorskite nanocomposites and the relationship between them were studied systematically in this paper. Because the nano-scale fibers of palygorskite were uniformly dispersed in the polyethylene matrix, and there is good bonding between the components, the nano-composites exhibit high tensile strength, excellent toughness, good chemical resistance, improved thermal stability, and high dimension stability. Obviously, the comprehensive property of the nanocomposites is superior to that of common PE.Supporting the active component on some high efficient, low costsupport to prepare high efficient catalyst with good morphology, simple process and low cost is an important task in the research of polyolefin catalyst. In this paper, the spherical natural palygorskite was selected as the support of high efficient catalyst for ethylene polymerization. By supporting MgC12.nC4H9OH/TiC14 catalytic component and MgCI2/THFITiC14 bimetallic active component on spherical palygorskite support, two kinds of high efficient spherical catalyst for ethylene polymerization were prepared. The new type catalysts exhibit good catalytic properties and they are suitable for the production of spherical liner low density polyethylene. The methodology of the preparation of the novel catalysts, and the properties of polyethylene produced with the catalysts were studied, too.