Hydroxyethyl cellulose (HEC) remains highly water-soluble over a wide temperature range, even in high-temperature regions where other non-ionic chemically modified cellulose ethers such as methyl cellulose (MC) and hydroxypropyl methyl cellulose (HpMC) exhibit turbidity points. To elucidate the cause of the high solubility of HEC, the temperature dependence of water composition nH for each glucopyran unit in HEC samples was examined over the following temperature ranges from 10 to 70 °C using extremely high frequency dielectric spectrum measurements up to 50 GHz.
In this study, HEC samples were examined for the molar number of hydroxyethyl substitutions (MS) of each glucose pyran unit ranging from 1.3 to 3.6. All HEC samples were dissolved in water within the temperature range examined and showed no turbidity points. The nH value of HEC samples with MS 1.3 is 14 at 20 °C, and decreases slowly with the temperature rising, and drops to 10 at 70 °C. The PH value of HEC sample is obviously larger than the minimum critical nH value of approx. 5 Cellulose ethers such as MC and HpMC must be dissolved in water, even in the high temperature range.
HEC molecules, however, are water-soluble over a wide temperature range. The temperature dependence of nH of HEC samples and triglycol (model compounds of HEC substituents) is mild and they are similar to each other. This observation strongly suggests that the hydration/dehydration behavior of HEC samples is largely controlled by their substituted groups. 3 is 14 at 20 °C, declines slowly as the temperature rises, and drops to 10 at 70 °C. The nH value of HEC sample is obviously larger than the minimum critical nH value of approx. 5 Cellulose ethers such as MC and HpMC must be dissolved in water, even in the high temperature range. HEC molecules, however, are water-soluble over a wide temperature range. The temperature dependence of nH of HEC samples and triglycol (model compounds of HEC substituents) is mild and they are similar to each other.
This observation strongly suggests that the hydration/dehydration behavior of HEC samples is largely controlled by their substituted groups. 3 is 14 at 20 °C, declines slowly as the temperature rises, and drops to 10 at 70 °C. The nH value of HEC sample is obviously larger than the minimum critical nH value of approx. 5 Cellulose ethers such as MC and HpMC must be dissolved in water, even in the high temperature range. HEC molecules, however, are water-soluble over a wide temperature range. The temperature dependence of nH of HEC samples and triglycol (model compounds of HEC substituents) is mild and they are similar to each other. This observation strongly suggests that the hydration/dehydration behavior of HEC samples is largely controlled by their substituted groups.
The nH value of HEC sample is obviously larger than the minimum critical nH value of approx. 5 Cellulose ethers such as MC and HpMC must be dissolved in water, even in the high temperature range. HEC molecules, however, are water-soluble over a wide temperature range. The temperature dependence of nH of HEC samples and triglycol (model compounds of HEC substituents) is mild and they are similar to each other. This observation strongly suggests that the hydration/dehydration behavior of HEC samples is largely controlled by their substituted groups. The nH value of HEC sample is obviously larger than the minimum critical nH value of approx. 5 Cellulose ethers such as MC and HpMC must be dissolved in water, even in the high temperature range. HEC molecules, however, are water-soluble over a wide temperature range. The temperature dependence of nH of HEC samples and triglycol (model compounds of HEC substituents) is mild and they are similar to each other.
This observation strongly suggests that the hydration/dehydration behavior of HEC samples is largely controlled by their substituted groups. HEC molecules are water-soluble over a wide temperature range. The temperature dependence of nH of HEC samples and triglycol (model compounds of HEC substituents) is mild and they are similar to each other. This observation strongly suggests that the hydration/dehydration behavior of HEC samples is largely controlled by their substituted groups. HEC molecules are water-soluble over a wide temperature range. The temperature dependence of nH of HEC samples and triglycol (model compounds of HEC substituents) is mild and they are similar to each other. This observation strongly suggests that the hydration/dehydration behavior of HEC samples is largely controlled by their substituted groups.