The antiscaling performance of phosphono carboxylic acid telomer (POCA), polyacrylic acid (PAA), acrylic acid-acrylic acid hydroxypropyl acrylate copolymer (T-225) and hydrolyzed polymaleic anhydride (HPMA) on Ca₃(PO₄)₂ was studied by static scale-inhibiting method. The results show that the efficiencies of scale inhibition of four polymers are 100%, 30.2%, 94.6% and 36.2% respectively when the quality of polymer is 25 mg/L. The interactions such as binding energies and non-bind energies between four carboxylic polymer scale inhibitors and (110) crystal surface of apatite had been simulated by molecular dynamics. The orders of binding energies and non-binding energies of four polymers with (110) crystal surface are as follows: POCA＞T-225＞HPMA＞PAA, the bigger the binding energies and non-binding energies, the stronger the binding effects between polymers and crystal surface, so the scale inhibiting effect on apatite is POCA＞T-225＞HPMA＞PAA which corresponds with the experiment results. According to the analysis of pair correlation functions of polymers with crystal surface, weak ionic bonds have been formed between oxygen of carbonyl of POCA, T-225 polymer and Ca^2＋ of apatite, but they are much less than non-bonding effects mainly provided by coulomb interaction and Van der Waals interaction, in which the prior is bigger than the latter. On the basis of above theory, the copolymers of maleic anhydride-sodium p-styrene sulfonate-acrylic acid hydroxypropyl acrylate (MA-SS-HPA) and sodium p-styrene sulfonate-acrylic acid hydroxypropyl acrylate-phosphorous acid (MA-SS-H₃PO₃) were synthesized, and their efficiencies of scale inhibition on apatite are 94.2% and 100% respectively when the quantity is 18 mg/L, that is to say their performance of scale inhibition is better than POCA.

Key words: carboxylic polymer scale inhibitor, apatite, antiscaling, molecular dynamics, binding energy, non-binding effect, synthesis