of total weight of carboxylic acid groups in the coating composition alternatively from 25 wt to 100 wt in some embodiments of the invention the initial ph of the aqueous composition is from 2 7 alternatively from 2 5 6 the target ph value preferably is from 7 8 to 9 3 alternatively from 8 to 9 2 in some embodiments of the invention the aqueous coating composition is an acrylic latex comprising copolymers of acrylic or methacrylic acid with c 1 c 8 alkyl acrylates or methacrylates in some embodiments of the invention the acrylic latex comprises 40 65 wt polymer solids alternatively 45 62 wt alternatively 45 55 wt a 3 neck round bottom flask equipped with a stir bar dropping funnel and nitrogen outlet was charged with 2 nitropropane 50 g 0 57 mol and 50 ml of methanol the mixture was stirred for 10 minutes and triethylamine 2 8 g 5 mol was added the pale yellow solution was stirred for additional 15 minutes to the above mixture 50 glutaraldehyde solution 56 7 g 0 28 mol was added drop wise over a period of 90 minutes via a dropping funnel after completion of the addition the solution was allowed to stir at room temperature for 48 h the solution was poured in a separatory funnel containing 150 ml of ice water the two phases were separated and the aqueous layer was extracted 2 u00d7 50 ml with diethyl ether the combined organic phase were washed with 2 u00d7 50 ml of water and dried over anhydrous magnesium sulfate and filtered the solvent was removed by rotary evaporator and the viscous residue was.