Sulfonyl azide group, RSO2N3, generates reactive nitrene intermediate by heat or irradiation. The nitrene functionality may then react with C-H bonds of hydrocarbon compound, resulting in modification of the compound. As a model study, non-catalytic and solvent-free postpolymerization modification of polyethylene was attempted employing polystyrene with sulfonyl azide functionality. Firstly, azo based initiator containing the sulfonyl azide functional groups was synthesized, followed by the polymerization of styrene using the initiator to afford polystyrene end-functionalized with sulfonyl azide groups(PS-SA). Commercially available high-density polyethylene (HDPE) was then thermally treated with the PS-SA by using Brabender melt mixer. The modified HDPE exhibited improved tensile mechanical properties, suggesting the potential of this value-adding approach as an efficient technical platform to modify various polymers.
Keywords: Sulfonyl azide, polyethylene, post-polymerization modification, mechanical property