Abstract
The impact of thermal stability on the performance of homo-, co-, and ter-polymers on the precipitation of calcium phosphate was investigated at pH 8.50, 50°C, calcium = 3.50 mM and phosphate = 0.095 mM. The polymers tested include: poly(acrylic acid), P-AA; poly(maleic acid), P-MA; poly(acrylic acid: 2-acrylamido-2-methyl propane sulfonic acid), P-AA:SA; P-AA:SA:t-bAm (ter-butylacrylamide), and P-AA:SA:SS (sulfonated styrene). It has been found that all polymers lose performance to a varying degree when exposed to thermal treatment. The performance data also suggest that SS containing ter-polymer is a better calcium phosphate inhibitor than t-bAm containing ter-polymer. In the case of co-polymer of AA:SA, the thermal treatment exhibits strong negative influence on the inhibitory power of polymer. The results have been explained in terms of loss of SA and t-bAM in the co- and ter-polymers leading to the formation of poly(acrylic acid).
