Table 1.
Radical-scavenging activity of the reaction products of isoeugenol (1) with ethanethiol, thiophenol, 2-mercaptothiazoline or 2-mercapto-1-methylimidazole (ISO-S-1 – ISO-S-4) in the polymerization of methyl methacrylate initiated by AIBN and BPO.
| AIBN | BPO | |||
|---|---|---|---|---|
| Compound | Relative n | kinb/kp | Relative n | kinb/kp |
| ISO-S-1 | 0.92 ± 0.05 | 36.43 ± 1.78 | 1.61 ± 0.08 | 8.88 ± 0.44 |
| ISO-S-2 | 0.96 ± 0.04 | 34.81 ± 1.71 | 1.19 ± 0.05 | 11.75 ± 0.58 |
| ISO-S-3 | 0.59 ± 0.02 | 56.63 ± 2.27 | 0.91 ± 0.04 | 15.46 ± 0.76 |
| ISO-S-4 | 1.01 ± 0.05 | 32.86 ± 1.48 | 0.25 ± 0.01 | 55.95 ± 2.79 |
| Isoeugenol | 1.11 ± 0.06 | 30.52 ± 1.36 | 1.75 ± 0.09 | 8.16 ± 0.42 |
n values calculated using Eqn. 2. kinb and kp are the rate constants of inhibition and propagation, respectively. The kinb/kp was calculated using Eqn. 5. MMA, 9.4 mol/L; compounds, 1mM; T=70°C; conversion: 90.3-95.3%; values, the mean ± SD for three different experiments.