Polymer crosslinking and functionalisation via a thermal azide-alkyne cycloaddition reaction

摘要

In general the methods of preparing crosslinked materials can be divided into two separate categories: (1) copolymerising monomers with a small amount of multifunctional monomer that direcdy forms a crosslinked network; and (2) crosslinking of preformed polymer chains in a secondary process. This brief paper claims a method of combining the best features of these two methods, by using the thermal azide-alkyne cycloaddition reaction. It is shown that polystyrene chains bearing random azide and alkyne groups, prepared by free radical polymerisation of styrene, TMS-protected propargyloxy-styrene and vinylbenzyl azide (followed by deprotection of the alkyne by tetrabutylammonium fluoride), undergo crosslinking when heated above 60°C. The relationship between crosslinking time and extent of extent of crosslinking was studied at several different temperatures (60-90°C).