silicone elastomers exhibiting non - transitory biofilm inhibiting properties are prepared from crosslinkable components which include an organopolysiloxane bearing at least one silicon - bonded hydrogen and / or at least one alkenyl group , and at least one carboxylic acid , carboxylic acid ester , or carboxylic acid anhydride group , which becomes covalently bonded to the polymer before or during curing .