THERMAL AND MECHANICAL PROPERTIES A MEMBRANE OF THE MIXING PVA NANOCOMPOSITE AND LIMESTONE HYDROXYAPATITE

Synthesis and characterization of membranes from a mixture of PVA nanocomposites and limestone hydroxyapatite have been carried out. The limestone is crushed, sieved with a size of 200 mesh. The synthesis of hydroxyapatite was carried out by heating limestone powder using a furnace at a temperature of 600 °C for 4 hours. Furthermore, limestone was dissolved with distilled water and 0.3M H3PO4 solution using a magnetic stirrer with stirring at 300 rpm for 1 hour. The pH of the solution was made 10 by adding 1 M NH4OH periodically. The solution was aged for 24 hours and the precipitate was dried using an oven at 120 °C for 5 hours. The hydroxyapatite powder was characterized by FTIR to see the functional groups and XRD characterization to see the hexagonal hydroxyapatite phase. The characterization results obtained that the main groups of hydroxyapatite compounds were calcium hydroxide (CaO), phosphate (PO4 3-), and hydroxyl (OH−) groups with a crystal size of 86.27 nm. Limestone hydroxyapatite was mixed with a solution of PVA-chitosan with a composition variation of 0%, 1%, 2%, 3%, and 4% weight using a magnetic stirrer at 40°C for 3 hours using the sol-gel method. The membrane obtained was characterized by DSC to determine its thermal properties and UTM to determine its mechanical properties. The maximum melting point obtained in the mixture (98: 2) % was 195.51°C and the highest tensile strength was at the percentage of 1% with a modulus of elasticity of 22.28 M.Pa and tensile strength of 13.23 M.Pa.