Table 1.
Matrix of factorial design 24 + 4C for binary polymeric systems composed of 15% (w/w) P407 and 0.25% (w/w) PCB, at 37 °C, and values for the low and high levels of each variable.
| Standard Run | Independent Variables | |||
|---|---|---|---|---|
| X1 | X2 | X3 | X4 | |
| 1 | A | − | − | − |
| 2 | B | − | − | − |
| 3 | A | + | − | − |
| 4 | B | + | − | − |
| 5 | A | − | + | − |
| 6 | B | − | + | − |
| 7 | A | + | + | − |
| 8 | B | + | + | − |
| 9 | A | − | − | + |
| 10 | B | − | − | + |
| 11 | A | + | − | + |
| 12 | B | + | − | + |
| 13 | A | − | + | + |
| 14 | B | − | + | + |
| 15 | A | + | + | + |
| 16 | B | + | + | + |
| 17 | A | 0 | 0 | 0 |
| 18 | B | 0 | 0 | 0 |
| 19 | A | 0 | 0 | 0 |
| 20 | B | 0 | 0 | 0 |
| Factor | − | 0 | + | |
| X1 | Substrate | A: Mucin disk | B: Oral pig mucosal | |
| X2 | Force (N) | 0.03 | 0.065 | 0.10 |
| X3 | Speed (mm/s) | 1.00 | 5.50 | 10.0 |
| X4 | Time (s) | 30.0 | 75.0 | 120.0 |