9 Experimental
Alliance GPC System Conditions Detection: 2414 RI RI flow cell: 35°C Mobile phase: THF Flow rate: 1mL/min
Columns: Styragel 4e, 2 and 0.5, 7.8 x 300 mm (3 in series) Column temp: 35 °C Sample diluent: THF Injection volume: 20µL
ACQUITY APC System Conditions Detection: ACQUITY RI RI flow cell: 35°C Mobile phase: THF Flow rate: 1mL/min
Columns: ACQUITY APC XT 200 Å and two 45 Å, 4.6 x 150mm (3 columns in series) Column temp: 35°C Sample diluent: THF Injection volume: 20µL
Data management Empower 3 CDS
Samples Waters Polystyrene Standards (100K, 10K, and 1000K) at 1mg/mL Epoxy resin at 2mg/mL
The improved resolution delivered by the APC System results in additional identifiable peak molecular weights for the 1K polystyrene standard. Using molecular weight information that may be determined from the standard supplier or from measurements of the standard using external methods, the additional points can then be added to the calibration curve, shown in Figure 2, adding confidence to the sample results calculated relative to this curve.
2.40 2.80 3.20 3.60 4.00 4.40 4.80 5.2 5.6
15
2.00 2.50 3.00 3.50 4.00 4.50 5.00 5.50
2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 16 17 18 19 20 21 Conventional GPC 3 x Styragel 7.8 x 300 mm
Typically, a series of standards are run to obtain the points in the calibration curve. With conventional GPC, the equilibration, preparation and analysis of each standard can take hours to days. As a result, the calibration may not be done frequently and results may be based on an ‘old’ calibration. With the ACQUITY APC System, equilibration is much faster due to the low system dwell volume and the run times are much shorter due to the use of smaller particles at higher flow velocity. Shortened run times allow the equilibration and calibration to be easily completed within one hour. Finally, with the additional resolution, fewer standards may need to be prepared and injected to obtain a robust curve that can be used for calibration.
When a sample is analysed, the greater robustness of the calibration allows for higher confidence in the molecular weight determinations of the low molecular weight oligomers. The analysis of an epoxy resin sample relative to polystyrene calibration standards is shown in Figure 3. The result shows resolution of oligomers with a run time of less than five minutes using three ACQUITY APC XT 4.6 x 150 mm Columns in series.
0.00 0.40 0.80 1.20 1.60 2.00 2.40 2.80 3.20 3.60 4.00 4.40 4.80 5.20 5.60 6.00
2.20 2.40 2.60 2.80 3.00 3.20 3.40 Minutes
Figure 3. An epoxy resin sample in THF using three ACQUITY APC XT 4.6 x 150mm columns in series with ACQUITY RI detection. Resolution of low molecular weight oligomers (shown by peak molecular weights) was achieved in less than five minutes.
The fast run times with APC can benefit reaction monitoring in process development. Increased resolution can facilitate faster identification of changes to the polymer that may occur in synthesis applications or degradation studies. Earlier detection of process changes by monitoring various molecular weights can provide a better understanding of the polymers and expected properties. This can facilitate the development of new polymers and lead to more rapid commercialisation.
Conclusions 22 Retention Time 23 24 25 26 27
ACQUITY APC System 3 x APC 4.6 x 150 mm
4.0 Retention Time 4.2 4.4 4.6 4.8 5.0
Figure 2. More points on the calibration curve for polystyrene standards (100K, 10K, and 1K) using the ACQUITY APC System, due to improved resolution of the 1K low molecular weight standard.
The Advanced Polymer Chromatography System provides significant improvements over conventional GPC systems due to lower dispersion in the system and higher backpressure capabilities that allow the use of smaller, hybrid particles. By combining the APC System with advancements in column technology, improved resolution of low molecular weight oligomers is also realised, compared to conventional GPC. APC performance benefits include more robust calibrations, which are essential in generating accurate measurements for polymer characterisation. The combination of speed and resolution improvements for low molecular weight polymers allows quick, reliable characterisation of polymers in the development process, which can facilitate fast-tracking of new polymers to market.
Waters, ACQUITY, Advanced Polymer Chromatography, APC, Empower, Alliance, and The Science of What's Possible are trademarks of Waters Corporation.
3.60 3.80 4.00 4.20 4.40 4.60
Log Mol Wt
Log Mol Wt
µRIU
6080 5239 4371 3954 3491 3051 2580 2105 1598 1056 650 495
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92 |
Page 93 |
Page 94 |
Page 95 |
Page 96 |
Page 97 |
Page 98 |
Page 99 |
Page 100 |
Page 101 |
Page 102 |
Page 103 |
Page 104 |
Page 105 |
Page 106 |
Page 107 |
Page 108 |
Page 109 |
Page 110 |
Page 111 |
Page 112 |
Page 113 |
Page 114 |
Page 115 |
Page 116 |
Page 117 |
Page 118 |
Page 119 |
Page 120 |
Page 121 |
Page 122 |
Page 123 |
Page 124 |
Page 125 |
Page 126 |
Page 127 |
Page 128 |
Page 129 |
Page 130 |
Page 131 |
Page 132 |
Page 133 |
Page 134 |
Page 135 |
Page 136 |
Page 137 |
Page 138 |
Page 139 |
Page 140 |
Page 141 |
Page 142 |
Page 143 |
Page 144 |
Page 145 |
Page 146 |
Page 147 |
Page 148 |
Page 149 |
Page 150 |
Page 151 |
Page 152 |
Page 153 |
Page 154 |
Page 155 |
Page 156 |
Page 157 |
Page 158 |
Page 159 |
Page 160 |
Page 161 |
Page 162 |
Page 163 |
Page 164 |
Page 165 |
Page 166 |
Page 167 |
Page 168 |
Page 169 |
Page 170 |
Page 171 |
Page 172 |
Page 173 |
Page 174 |
Page 175 |
Page 176 |
Page 177 |
Page 178 |
Page 179 |
Page 180 |
Page 181 |
Page 182 |
Page 183 |
Page 184 |
Page 185 |
Page 186 |
Page 187 |
Page 188 |
Page 189 |
Page 190 |
Page 191 |
Page 192 |
Page 193 |
Page 194 |
Page 195 |
Page 196 |
Page 197 |
Page 198 |
Page 199 |
Page 200 |
Page 201 |
Page 202 |
Page 203 |
Page 204 |
Page 205 |
Page 206 |
Page 207 |
Page 208 |
Page 209 |
Page 210 |
Page 211 |
Page 212 |
Page 213 |
Page 214 |
Page 215 |
Page 216 |
Page 217 |
Page 218 |
Page 219 |
Page 220 |
Page 221 |
Page 222
