Characterization of new acrylic bone cement based on methyl methacrylate/1-hydroxypropyl methacrylate monomer

New formulations of acrylic bone cement based on methyl methacrylate/1-hydr oxypropyl methacrylate (MMA/HPMA) monomers were developed with the purpose of obtaining more ductile materials with reduced polymerization shrinkage. In this way, the ductility of such materials increased, but the introductio n of high percentages of the hydrophilic component produced an important de crease in Young's modulus and strength. To ascertain the reason for the det erioration of the tensile parameters, an analysis by scanning electron micr oscopy of these formulations was carried out; it revealed poor adhesion bet ween the matrix and poly(MMA) beads. We also observed that the polymerizati on shrinkage increased as the amount of hydrophilic monomer in the formulat ion decreased, and the 50% (v/v) HPMA modified bone cement compensated for this volume reduction with its water uptake swelling. Measurements taken on the setting time and polymerization exotherm showed a decrease in the form er and an increase in the latter, because of the introduction of a more rea ctive monomer in the bone cement formulation. (C) 1999 John Wiley & Sons, I nc.