Synthesis of hydroxyapatite powder using natural latex particles as pore-creating agent

Abstract

This research aims to determine the appropriate empirical model of hydroxyapatite particles' surface area produced using natural rubber as porogen. Firstly, a 100-mL solution of Ca(NO3)2 and latex were added dropwise into 100 mL of [(NH4)2HPO4] solution at 37 °C under stirring variations of 200 and 300 rpm for 30 and 45 min, respectively. Subsequently, the solution was aged for 12 and 24 h, washed, filtered, and dried in an oven at 110 °C for 5 h. Finally, a furnace was used for calcining the sample for 5 h at 600 °C. The empirical model obtained to control the surface area of porous hydroxyapatite particles with the addition of latex was Y = 645.2 − 2,241A − 16.61B − 31.35C + 0.06106A * B + 0.1190A * C + 0.8650B*C − 0.003293A * B * C. The R2 obtained for this model was 99.99%. Three-way interaction between stirring time and aging time (ABC), variable stirring time (B), two-way interaction between stirring time and aging time (BC), stirring speed (A), two-way interaction between stirring speed and stirring time (AB), and aging time (C), in the order of greatest to smallest effect. The highest hydroxyapatite surface area was 49 m2/g, which was produced at 30 min of stirring time, 200 rpm stirring speed, and 12 h of aging time.