TABLE I.
DMA Data for Control and Experimental Adhesives
| Sample | Modulus at 37°C (MPa) | Rubbery modulus (MPa) | Tg (°C) | Height of tan δ peak | Full-width-at-half-maximum values of tan δ peak (°C) |
|---|---|---|---|---|---|
| C0 | 3600 (200)a | 31 (8) | 145 (1)b | 0.67 (0.04) | 32.9 (1.0) |
| C5 | 3200 (96) | 26 (2) | 135 (3) | 0.75 (0.03) | 40.5 (0.6) |
| C10 | 2800 (160) | 17 (3) | 123 (6) | 0.72 (0.07) | 44.7 (3.3) |
| C15 | 2700 (170) | 15 (2) | 126 (4) | 0.79 (0.06) | 48.6 (6.3) |
| E0 | 4000 (60)* | 44 (4) | 144 (1) | 0.62 (0.02) | 39.8 (0.9) |
| E5 | 3500 (90)** | 36 (3)** | 146 (1)** | 0.64 (0.02)** | 41.0 (1.5) |
| E10 | 3200 (70)† | 33 (2)† | 152 (2)† | 0.65 (0.02)† | 39.4 (0.5) |
| E15 | 3200 (200)†† | 34 (4)†† | 157 (4)†† | 0.63 (0.04)†† | 38.9 (3.1)†† |
a
Entries are mean values of five specimens with standard deviations in parentheses. Symbols: C0, C5, C10, and C15, control formulations polymerized at 0%, 5%, 10%, and 15% water; E0, E5, E10, and E15, experimental formulations polymerized at 0%, 5%, 10%, and 15% water.
b
The glass transition temperatures (Tg) values of the polymer networks were taken to be the maximum of the tan δ versus temperature curve determined using a dynamic mechanical analyzer.
*
Significantly (p < 0.05) different from control C0;
**
Significantly (p < 0.05) different from control C5;
†
Significantly (p < 0.05) different from control C10;
††
Significantly (p < 0.05) different from control C15.