Table 1. Influence of Reaction Time on Amide Bond Formation of Hydrogelsa.
| malic
acid |
glutaric acid |
||||||
|---|---|---|---|---|---|---|---|
| sample | Treaction (K) | treaction (h) | int. ratioCN/CH2 | sample | Treaction (°C) | treaction (h) | int. RatioCN–CH2 |
| chitosan | 0.42 | chitosan | 0.42 | ||||
| MA 251.5 | 298.15 | 1.5 | 0.75 | GA 251.5 | 298.15 | 1.5 | 0.85 |
| MA 253 | 3 | 2.07 | GA 253 | 3 | 1.93 | ||
| MA 254.5 | 4.5 | 2.09 | GA 254.5 | 4.5 | 2.24 | ||
| MA 256 | 6 | 2.26 | GA 256 | 6 | 2.35 | ||
| MA 258 | 8 | 2.30 | GA 258 | 8 | 2.80 | ||
| MA 2524 | 24 | 2.92 | GA 2524 | 24 | 3.06 | ||
| MA 401.5 | 313.15 | 1.5 | 0.94 | GA 401.5 | 313.15 | 1.5 | 1.70 |
| MA 403 | 3 | 2.00 | GA 403 | 3 | 1.86 | ||
| MA 404.5 | 4.5 | 2.01 | GA 404.5 | 4.5 | 2.18 | ||
| MA 406 | 6 | 2.05 | GA 406 | 6 | 2.27 | ||
| MA 408 | 8 | 2.42 | GA 408 | 8 | 3.12 | ||
| MA 4024 | 24 | 2.87 | GA 4024 | 24 | 3.22 | ||
| MA 501.5 | 323.15 | 1.5 | 2.11 | GA 501.5 | 323.15 | 1.5 | 1.84 |
| MA 503 | 3 | 2.62 | GA 503 | 3 | 2.17 | ||
| MA 504.5 | 4.5 | 2.69 | GA 504.5 | 4.5 | 2.25 | ||
| MA 506 | 6 | 2.88 | GA 506 | 6 | 2.32 | ||
| MA 508 | 8 | 3.01 | GA 508 | 8 | 3.17 | ||
| MA 5024 | 24 | 3.13 | GA 5024 | 24 | 3.46 | ||
a
For calculating the absorbance intensity ratio, the intensities of characteristic infrared frequencies of stretching vibration of C–N in the amide bond (1081 cm–1) and stretching vibration of C–H in the pyranose ring (2884 cm–1) have been used.