RESUMO
Polyolefins that contain polar functionalities are highly desired because they could extend the range of applications of these low production cost materials by modifying surface and other interfacial properties. Block copolymers containing polyolefin and polar segments are among the most sought-after architectures because of their ability to span the phase boundaries. This review focusses on the end-functionalisation of polyolefins by catalytic olefin polymerisation processes, almost invariably by metal-catalysed routes, followed by the growth polar blocks by various polymerisation techniques.
RESUMO
A new metallocene-based polymerization mechanism is elucidated in which a zirconium hydride center inserts α-methylstyrene at the start of a polymer chain. The hydride is then regenerated by hydrogenation to release a polyolefin containing a single terminal α-methylstyrenyl group. Through the use of the difunctional monomer 1,3-diisopropenylbenzene, this catalytic hydride insertion polymerization is applied to the production of linear polyethylene and ethylene-hexene copolymers containing an isopropenylbenzene end group. Conducting simple radical polymerizations in the presence of this new type of macromonomer leads to diblock copolymers containing a polyolefin attached to an acrylate, methacrylate, vinyl ester, or styrenic segments. The new materials are readily available and exhibit interfacial phenomena, including the mediation of the mixing of immiscible polymer blends.
