OPTIMIZATION OF BENZOYL PEROXIDE CONCENTRATION IN AN EXPERIMENTAL BONE-CEMENT BASED ON POLY(METHYL METHACRYLATE)

The effect of the concentration of benzoyl peroxide in poly(methyl met hacrylate) bone cement formulations on their setting characteristics, particularly peak temperature and setting time, were studied. An optim ization of the concentration of benzoyl peroxide was made with respect to curing parameters and compared with the residual monomer content. The mechanical properties of the different formulations were also dete rmined and the results indicated that a composition of 1.5% wt/wt and 0.82% wt/wt of benzoyl peroxide and N,N-dimethyl-p-toluidine concentra tions, respectively, gave the highest yield strength. Studies on the p reparation of bone cement formulations containing different amounts of barium sulphate were also performed to assess the effect on the polym erization process and mechanical properties of the cements.