Two-way analysis of variance (two-way ANOVA) was used to
identify any significant difference in the friction coefficient values
of the PVP solutions with different concentrations as well as solvents.
A Bonferroni adjustment was chosen for all the multiple
comparisons. The viscosity, surface tension and static contact
angle from the different groups were also compared using twoway
ANOVA, respectively. Student's t-test (t-test) was used to
analyze the difference in wear volume between the PVP solutions
with different concentrations. Significance for all the tests was
defined as Po0.05.