270273.fig.004
Figure 4: The main effects of the parameters on the ultimate strength of the crosslinked PPF composites. A positive number indicates an increase in the strength as the parameter was changed from a low (−) level to a high (+) level. A negative number indicates a decrease in the strength as the parameter was changed from a low (−) level to a high (+) level. Error bars represent the standard error of the effect (dry ± 16.5 MPa, wet ± 6.2 MPa).