Fluorescent-Tagged No Phosphate and Nitrogen Free Calcium Phosphate Scale Inhibitor for Cooling Water Systems

Allyloxy polyethoxy ether (APEO) and chloracetic acid were used to prepare allyloxy polyethoxy carboxylate (APEC). 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt was reacted with allyl chloride to produce fluorescent monomer 8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (AP). APEC and AP were copolymerized with maleic anhydride (MA) to synthesize AP tagged no phosphate and nitrogen free calcium phosphate inhibitor MA-APEC-AP. Structures of AP, APEO, APEC, and MA-APEC-AP were carried out by FTIR and H-1-NMR. Different MA : APEC mole ratios were employed for the manufacture of MA-APEC-AP to study the effect of mole ratio on performance of MA-APEC-AP. Relationship between MA-APEC-AP's fluorescent intensity and its dosage was studied. MA-APEC-AP's calcium phosphate inhibition was compared with the down to date calcium phosphate inhibitor (MA)ammonium allylpolyethoxy sulphate (APES). The results indicate that capability of MA-APEC-AP is heavily depended on the mole ratio of MA : APEC. Correlation coefficient r of MA-APEC-AP's fluorescent intensity and its dosage is 0.9983, and detection limit of MA-APEC-AP is 2.03 mg L-1. MA-APEC-AP can be used to accurately measure polymer consumption on line besides providing excellent calcium phosphate inhibition. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 113: 1966-1974, 2009