Table 2: Activation parameters of caffeine in different PEG media.

Type of PEGPEG % (V/V) at 300 KEquation obtained for plot of
ln( / ) versus (103/ )
# # # J/Kmol
kJ/mol

PEG-2000.50.4 0.98534.175.2138
1.00.5 0.96332.474.7141
2.00.6 0.96828.374.5154
3.00.6 0.98943.574.7103
4.00.7 0.99937.274.2123
5.00.9 0.99933.173.6135

PEG-3000.50.2 0.99747.576.699.7
1.00.3 1.0036.576.1132
2.00.4 0.98634.175.5138
3.00.5 0.99825.075.1167
4.00.6 0.99517.874.5189
5.00.7 0.99615.473.5196

PEG-4000.50.2 0.99233.975.6139
1.00.4 0.97413.670.0188
2.00.5 0.99810.864.8180
3.00.6 0.9998.9061.4175
4.00.7 0.97125.174.0163
5.00.8 0.99225.073.6162

PEG-6000.50.2 0.98041.377.0119
1.00.3 0.98831.376.3150
2.00.4 0.99225.175.5168
3.00.6 0.96613.570.8191
4.00.7 0.96311.667.1185
5.00.9 0.9995.4255.5167