PMMA/Ca~(2+) BONE CEMENTS. PART I. PHYSICO CHEMICAL AND THERMOANALYTICAL CHARACTERIZATION

摘要

Acrylic bone cements of poly (methyl methacrytate) (PMMA) have been used for about 40 years to fix artificial prosthesis to bone structure. The objective of this study was to evaluate the thermo analytical properties such as setting time, peak temperature and polymerization enthalpy of PMMA/Ca~(2+) bone cements, besides of their physico chemical characterization. Amounts of mineral component were supplied like a mixture of hydroxy apatite (Coralina~R HAP-200 or HA 3) and ealcium carbonate (aragontte from natural sources). Setting time, peak temperature and polymerization enthalpy were performed in all the formulations guiding by a fractional experimental design. The physico chemical characterization showed an expected pattern from the raw materials and matrix composition. The residual monomers were evaluated through ~1H NMR spectroscopy and showed a low value (< 1 mol %). Thermo analytical parameters were determined. The setting time obtained ranged between 3.6 and 8.0 minutes and the peak temperature varied between 62 and 110 °C Polymerization enthalpy was less than reported for the monomer and the obtained value swinging between 1 and 8 kJ/mol.