The mechanical properties of compacts of microcrystalline cellulose (MCC) a
nd silicified microcrystalline cellulose (SMCC) were evaluated by tensile t
esting, diametric compression testing, and compression testing. For tensile
and compression testing, cubic specimens were carefully machined from MCC
and SMCC compacts, and the tensile and compression strengths were evaluated
both normal and parallel to the compaction direction. The cubic tensile st
rengths were compared to values obtained from the diametric compression tes
t. The results obtained using the diametric compression test suggested comp
acts of SMCC exhibit greater strength than those of MCC. In addition, the c
ubes machined fi-om compacts of MCC and SMCC exhibited directional strength
: the direction normal to the compaction direction displayed the greater te
nsile strength; and the parallel direction had greater compression strength
. The diametric compression test afforded strength values with reduced spre
ad compared to the values collected from the cubic tensile test, suggesting
that the errors involved in collecting diametric compression test data of
compacts are less than those for the cubic tensile test. Analysis of the cu
bes using X-ray diffraction (XRD) suggested that they display directional s
tructural anisotropy, with the direction normal to the compaction direction
being more crystalline than the parallel direction. However, it is not cle
ar whether the difference in the directional strength is solely a consequen
ce of the increased crystallinity or a culmination of crystallographic and
mechanical keying effects.