Concentration of boric acid (%) | Glass transition temperature (˚C) | ||
PH PVA | FH PVA | M PVA | |
0 | 72 | 79 | 76 |
0.5 | 72 | 80 | 79 |
1 | 75 | 81 | 78 |
1.5 | 80 | 87 | 83 |