LAUSR

The enthalpy increments (ΔH) of glass (BSG, AlBSG, BaBSG, PbBSG)-bonded composites of strontium chloroapatite [Sr10(PO4)6Cl2] loaded with 10 mass% simulated chloride waste were measured by drop calorimetry at 373–773 K in air. These data were then fitted to an empirical equation, HT0–H298K0 = a + bT + cT2 + d/T by using least square method. From the fitted equation, the heat capacity (Cp) values were computed. Cp values evaluated from drop calorimetry method were compared with the Cp values available in the literature. The Cp data determined from drop calorimetry on the composites are reported for the first time and are found to be 0.60–0.98, 0.57–0.87, 0.54–0.85 and 0.52–0.77 J g−1 K−1 for SrApCl-10w20BSG, SrApCl-10w20AlBSG, SrApCl-10w20BaBSG and SrApCl-10w20PbBSG, respectively, at 373–773 K. The Cp determined for pristine glasses are found to be in the range of 0.85–1.10, 0.80–1.05, 0.58–1.06 and 0.57–0.93 J g−1 K−1, respectively, for BSG, AlBSG, BaBSG and PbBSG and are higher than the Cp values of corresponding glass-bonded composites.