Polyolefin-carbon nanotube composites by in-situ polymerization

The in-situ polymerization of olefins such as ethylene and propylene (PP) in the presence of carbon nanotubes (CNTs) is one of the most efficient and versatile ways to synthesize polyolefine nanocomposites. Since a good interfacial adhesion between polyolefin matrix and carbon nanotubes is crucial for successful preparation, the polymerizations were performed with methylaluminoxane (MAO) anchored covalently to the surface of the nanotubes. Thus, a heterogeneous co-catalyst is formed and the polymerization starts with the addition of ethylene or propylene directly on the tube surface. The resulting nanocomposites contain 0.1-25.0. wt% of homogeneous distributed CNT and a good separation of the individual tubes. They show better crystallization temperatures, temperature stability and mechanical properties than unfilled polyolefins.