“…Although an attempt to increase the peroxide loading density by coupling UHMWPE 4c with diazonium salt 7b gave material 8 , when converted into adduct 9 it did not exhibit any higher loading than the base material. That these loading levels had potential application was suggested by incubation of modified XAD 6a , UHMWPE 6c , and PP 6f with Streptococcus aureus overnight, and these demonstrated substantial levels of antibacterial activity, with kill zones of 38, 37, and 22 mm (a zone of 11 mm is considered to be inactive) (Figure ). That this bioactivity resulted from the combination of surface modification and the presence of hydrogen peroxide was established from appropriate controls; thus, modified polymers 4a , c and f which were not treated with hydrogen peroxide, and unmodified polystyrene XAD‐4, UHMWPE, and PP which were all treated with hydrogen peroxide followed by washing, displayed no biocidal activity in identical assays.…”