Palladium catalysed copolymerisation of ethene with alkylacrylates: polar comonomer built into the linear polymer chainElectronic supplementary information (ESI) available: NMR data for entries 1, 9, 10, 12 and size exclusion chromatographic data for entries 1, 3, 8, 12. See http://www.rsc.org/suppdata/cc/b1/b111252j/