| Concentration of boric acid (%) | Molecular weight | ||
| PH PVA | FH PVA | M PVA | |
| 0 | 99,030 | 94,478 | 31,662 |
| 0.5 | 104,492 | 94,924 | 32,430 |
| 1 | 104,688 | 95,174 | 32,840 |
| 1.5 | 105,732 | 95,561 | 32,605 |