Fluorescent-tagged maleic anhydride-allylpolyethoxy carboxylate copolymer as an environmentally benign inhibitor for calcium phosphate in industrial cooling systems



Allyloxy polyethoxy ether (APEG) and succinic anhydride were used to prepare allyloxy polyethoxy carboxylate (APEL). 8-hydroxy-1,3,6-pyrene trisulfonic acid trisodium salt (PY) was reacted with allyl chloride to produce fluorescent monomer 8-allyloxy-1,3,6-pyrene trisulfonic acid trisodium salt (PA). APEL and PA were copolymerized with maleic anhydride (MA) to synthesize PA tagged no phosphate and nitrogen-free calcium phosphate inhibitor POLY(MA–APEL–PA). Structures of PA, APEG, APEL, and POLY(MA–APEL–PA) were carried out by FTIR and 1H-NMR. Different MA : APEL mole ratios were employed for the manufacture of POLY(MA–APEL–PA) to study the effect of mole ratio on performance of POLY(MA–APEL–PA). Relationship between POLY(MA–APEL–PA)'s fluorescent intensity and its dosage was studied. The results indicate that capability of POLY(MA–APEL–PA) is heavily depended on the mole ratio of MA : APEL. Correlation coefficient r of POLY(MA–APEL–PA)'s fluorescent intensity and its dosage is 0.9999, and detection limit of POLY(MA–APEL–PA) is 0.86 mg/L. POLY(MA–APEL–PA) can be used to accurately measure polymer consumption on line besides providing excellent calcium phosphate inhibition. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers