Viscosities and densities (measured at 30 °C) and scanning thermogravimetry-determined short-term thermal stabilities of ILsa.
IL | Dynamic viscositya (mPa s) | Kinematic viscositya (mm2 s−1) | Densitya (g cm−3) | T der b (°C) | T dcp c (°C) | Transition shape d | Residual char e | |
---|---|---|---|---|---|---|---|---|
1 | [MeOCH2CH2-PEt3][Tf2N] | 36.0 | 26.3 | 1.368 | 468 | 362 | M | 2.6% |
2 | [MeOCH2CH2-PBu3][Tf2N] | 122.5 | 99.0 | 1.237 | 449 | 354 | M | 1.0% |
3 | [MeOCH2CH2-PBu3][beti] | 163.4 | 127.1 | 1.286 | 425 | 318 | M | 0.9% |
4 | [Me(OCH2CH2)2-PBu3][Tf2N] | 95.5 | 78.6 | 1.215 | 445 | 319 | M | 1.4% |
5 | [Me(OCH2CH2)3-PBu3][Tf2N] | 79.8 | 66.8 | 1.195 | 448 | 318 | M | 1.7% |
6 | [Me(OCH2CH2)4-PBu3][Tf2N] | 90.2 | 75.0 | 1.203 | 450 | 335 | M | 2.2% |
7 | [MeOCH2CH2-Et-Im][Tf2N] | 33.1 | 22.7 | 1.458 | 468 | 401 | S | 3.4% |
8 | [MeOCH2CH2-Py][Tf2N] | 44.5 | 29.5 | 1.508 | 456 | 403 | M | 2.8% |
9 | [MeOCH2CH2-Et3N][Tf2N] | 61.4 | 44.4 | 1.383 | 427 | 380 | S | 0.0% |
10 | [MeOCH2CH2-Me-Pip][Tf2N] | 84.2 | 59.0 | 1.426 | 453 | 399 | S | 0.3% |
11 | [BMIM][Tf2N] | 41.4 | 28.9 | 1.430 | 464 | 406 | S | 1.5% |
12 | [BMIM][PF6] | 205.8 | 151.1 | 1.362 | 472 | 424 | S | 0.5% |
The viscosity and density data were acquired using an Anton Paar SVM 3000 viscometer; measurements were made at 30 °C. Thermogravimetric analysis (TGA) scans were measured on a TA Instruments TGA Q50 under a nitrogen atmosphere (60 mL min−1) using Pt pans with a heating rate of 10 °C min−1.
T der is determined from the maximum in the first-derivative profile of the TGA scan.
T dcp is the decomposition temperature measured as the onset of decomposition, using the common criterion of 10% total mass loss. Uncertainties in the temperatures are estimated to be on the order of ±2–3 °C.
The TGA mass loss behavior is qualitatively characterized on the basis of whether it occurs essentially in a single, discrete step (S) or exhibits multiple step (M) thermal decomposition. The latter is generally associated with an early mass loss step which occurs at a temperature 50–100 °C below the primary event within the vicinity of Tder. It should be noted that, for this reason, profiles that display some multi-step thermal decomposition character generally have lower effective Tdcp values.
The amount of carbon char residue is determined from the relative mass remaining at 600 °C; a residue amount on the order of ±1–2% should be considered within the error of the measurement baseline.