| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 1375526 | Carbohydrate Polymers | 2014 | 6 Pages |
•Water soluble, thermo-responsive 3-(2-butoxy(ethoxy)m)-2-hydroxypropyl starch ethers (BEmS) (m = 0, 1 or 2) were prepared.•The LCSTs of BEmS could be tuned in wide range by increasing the length of oligo(ethylene glycol) spacers.•Hydrophilic oligo(ethylene glycol) not only increase the LCST, but also reduce effects of NaCl and BEmS concentrations on the LCSTs.
Water soluble, thermoresponsive 3-[2-butoxy(ethoxy)m]-2-hydroxypropyl starch ethers (BEmS) (m = 0, 1, or 2) were prepared by reacting degraded waxy maize starch with n-butyl glycidyl ether, 3-(2-n-butoxyethyl) glycidyl ether, and 3-[2-(2-n-butoxyethoxy)ethyl] glycidyl ether, respectively. The lower critical solution temperatures (LCSTs) of BEmS could be tuned to a wide range from 17.5 °C to 55.0 °C by changing the side chain lengths of oligo(ethylene glycol) groups and their average molar substitution (MS). The LCSTs of BEmS increase with increasing side chain length of oligo(ethylene glycol) groups when BS, BES, and BE2S have similar MS values. By contrast, an increase in BEmS concentration and addition of NaCl to the BEmS solutions could lead to a decrease in the LCSTs of BEmS. In addition, the effects of NaCl and BEmS concentrations on the LCSTs become weaker when the side chain length of oligo(ethylene glycol) groups increase.
