A. Nzihou et al., A RHEOLOGICAL, THERMAL AND MECHANICAL STUDY OF BONE-CEMENT - FROM A SUSPENSION TO A SOLID BIOMATERIAL, Powder technology, 99(1), 1998, pp. 60-69
Surgical bone cements are mainly based on acrylic (co)polymers, poly(m
ethyl methacrylate) (PMMA) being the most representative. The curing p
rocess is the result of free radical polymerization of a suspension of
PMMA powder and methyl methacrylate. The fundamental characteristic o
f the suspensions before polymerization is the viscosity. Therefore, i
n this paper, the rheological study of a suspension evolving to hard c
ement by polymerization is discussed. The effect of concentration (vol
ume fraction) of solids, temperature and nature of inorganic compounds
used as filler and opaque substances to X-ray radiations on the visco
sity of the suspension are examined. Experimental data and models are
discussed. The rheological behaviour corresponds to a shear-thickening
model typical for concentrated suspension and data fit to a modified
Chong equation. Bone cements obtained by polymerization of the suspens
ion were characterized by differential scanning calorimetry to determi
ne the heat released during the polymerization, the degree of reaction
and the glass transition temperature. Mechanical properties are also
reported and compared with results for existing commercial sources for
bone cement. (C) 1998 Elsevier Science S.A. All rights reserved.