Ethylene Glycol Dicarboxylate

Ethylene glycol diacetate should avoid contact with alkali, acid, oxidizing agent and reducing agent during storage. The compound is a flammable liquid and is non-corrosive to metals. It can be stored in iron, mild steel or aluminum containers, but copper containers are not suitable because the acetic acid produced by decomposition is corrosive to copper. It is best to store it in a cool, dry and well-ventilated warehouse, away from fire, heat sources and direct sunlight.

The cross-linked poly(ethylene glycol) dicarboxylate (PEGDC)/poly(ethylene oxide) (PEO) and poly(ethylene glycol) dimethacrylate (PEGDMA)/(PEO) hydrogels were developed for possible biomedical applications such as an anti-adhesion barrier. Various contents of PEGDC/PEO film were irradiated using an electron beam with various beam intensities in order to obtain various degrees of crosslinked hydrogels. The optimum dose (300 kGy) and total crosslinker content of 10% were used to prepare crosslinked hydrogel films with three different compositions (10% PEGDC, 10% PEGDMA, 5% PEGDC–5% PEGDMA). Among them, 10% PEGDC hydrogel film exhibited the highest elongation at break (69.33 ± 6.87%) with high mechanical strength. 10% PEGDC hydrogel film showed the lowest hemolysis activity (6.03 ± 0.01%) and the highest tissue adherence (75.67 ± 1.15 cN). The result also indicated that the carboxyl groups in PEGDC affect the tissue adherence of hydrogel films via H-bonding interactions. In animal studies, 10% PEGDC anti-adhesion hydrogel film degraded within 3 weeks and demonstrated better anti-adhesive effect compared to Guardix-SG®.

Ethylene glycol with the formula CH2OH2, also known as 1,2-ethanediol, is a popular organic compound. The safety data sheet for ethylene glycol, as well as for other substances, is the primary source of information on their physical and chemical properties. Ethylene glycol is the main component of antifreeze in HVAC and automotive systems. The formula of glycol clearly indicates that it belongs to a chemical group of dihydroxy alcohols, also known as diols. Thus, glycol as an alcohol is a colourless liquid with a high viscosity and a sweet taste. In addition to its excellent miscibility with water, it is also very soluble in aldehydes, ketones and acetic acid, but it does not dissolve at all in carbon tetrachloride. It is relatively cheap to produce. Its disadvantage is crystallisation at low temperatures and lower (compared to propylene glycol) ability to absorb heat (that is about 50% of the heat capacity of water).

Ethylene glycol has a high boiling point (197ᵒC) while having a low molecular weight. This is due to the strong association of molecules in the liquid phase, caused by the formation of hydrogen bonds. In its pure form, ethylene glycol freezes at about -13°C, while the ethylene glycol: water mixture can remain liquid at much lower temperatures. A mixture of 40% water and 60% glycol, for example, can withstand temperatures down to about -37ᵒC. It should be noted that ethylene glycol is miscible with water in all proportions. This is due to the presence of two hydroxyl groups in its structure.

In a 125 mL two-necked round-bottomed flask, add a certain amount of ethylene glycol, glacial acetic acid, dehydration entrainer (such as benzene, toluene, cyclohexane, etc.), catalyst, shake well, then add a few small grains of zeolite, and place it at the mouth of the flask. Connect the moisture separator, and then connect the upper end of the moisture separator to the spherical reflux condenser tube. Install a thermometer on the other end of the flask. Place the flask on an electric stove and heat to reflux. During the reflux process, when the lower liquid level in the water separator is about to reach the branch pipe opening, release 5 mL of accumulated liquid from the lower end, and then continue to reflux. When the lower liquid level in the moisture separator does not change within 10 minutes, then reflux for 30 minutes, remove the moisture separator and spherical condenser tube, connect the straight tube condenser tube, and proceed with distillation (generally reflux for 3 hours) ). In the fraction before the boiling point of the pure dehydration entrainer, add 1% sodium hydroxide solution dropwise to make the fraction neutral. The oil in the upper layer can be considered as the pure dehydration entrainer for use as a pure dehydration entrainer next time. . Collect the 186~192 C fraction to obtain colorless and transparent ethylene glycol diacetate. When using concentrated sulfuric acid as a catalyst, after the photoreaction refluxes for 2 hours, remove the water separator and spherical condenser tube, connect a straight tube condenser tube, distill to 150 C, stop heating, cool, and add people to the flask. 40.mL water, use anhydrous sodium carbonate powder to adjust the pH value of the reaction solution to 7~8, then use a separatory funnel to separate the oil layer (at the bottom of the separation liquid), dry it with anhydrous magnesium sulfate, filter, and the filtrate is distilled , collect the 186~192 C fraction.