Definition and Usage Areas of Polyethylene glycol
Polyethylene glycol production was first reported in 1859. Both AV Laurence and Charles Adolphe Wurtz independently isolated the products with polyethylene glycols. It is produced by interaction with polyethylene glycol, ethylene oxide, water, ethylene glycol or ethylene glycol oligomers. The reaction is catalyzed by acidic or basic catalysts. Ethylene glycol and its oligomers are preferred as a starting material over water, as they allow the production of polymers with low polydispersity (narrow molecular weight distribution). The polymer chain length depends on the ratio of the reactants.
HOCH 2 , CH 2 , OH + n (CH 2 CH 2 O) → HO (CH 2 CH 2 O) n + 1 ‘H
Depending on the nature of the catalyst, the polymerization mechanism can be cationic or anionic. The anionic mechanism is preferred because PEG can be obtained with low polydispersity. Ethylene oxide polymerization is an exothermic process. Overheating or contamination of ethylene oxide with catalysts such as alkalis or metal oxides can cause overpolymerization which can cause an explosion after a few hours.
It is synthesized by suspension polymerization of polyethylene oxide or high molecular weight polyethylene glycol. It is necessary to keep the growing polymer chain in solution during the polycondensation process. The reaction is catalyzed by organoelement compounds of magnesium, aluminum or calcium. Clipping additives such as dimethylgloxime are used to prevent the polymer chains from dissolving.
Alkaline catalysts are used to prepare a low molecular weight polyethylene glycol such as sodium hydroxide (NaOH), potassium hydroxide (KOH), or sodium carbonate (Na2CO3).
- Because PEG is hydrophilic molecule, it is used to passivate microscope glass slides to prevent non-specific adhesion of proteins in single-molecule fluorescence studies.
- Polyethylene glycol is low in toxicity and is used in a variety of products.
- The polymer is used as a lubricating coating for a variety of surfaces in aqueous and non-aqueous environments.
- Because PEG is a flexible, water-soluble polymer, it can be used to create very high osmotic pressures.
- Polyethylene glycol is widely used as a polar stationary phase for gas chromatography as well as a heat transfer fluid in electronic test equipment.
- PEG is often used in mass spectrometry experiments with its characteristic fragmentation pattern that allows for accurate and reproducible tuning.
- PEG derivatives such as narrow-range ethoxylates are used as surfactants.
- PEG has been used as the hydrophilic block of amphiphilic block copolymers used to form some polymers.
- PEG is the basis of a number of laxatives. Whole bowel irrigation with polyethylene glycol and additional electrolytes is used for bowel preparation prior to surgery or colonoscopy.
- PEG is also used as an excipient in many pharmaceutical products.
- When bound to various protein drugs, polyethylene glycol allows the transported protein to be slowed in the blood.
- PEG is commonly used as a crowding agent in in vitro experiments to mimic highly populated cellular conditions.
- PEG is commonly used as a precipitate for plasmid DNA isolation and protein crystallization. X-ray diffraction of protein crystals can reveal the atomic structure of proteins.
- PEG is used to fuse two different types of cells, mostly B-cells and myelomas, to form hybridomas.
- Polymer fragments derived from PEG polyols add flexibility to polyurethanes for applications such as elastomeric fibers (spandex) and foam pillows.
- In microbiology, PEG precipitation is used to concentrate viruses.
- Gene therapy vectors (such as viruses) are coated with PEG to protect them from inactivation by the immune system, and can remove them from organs and prevent them from being targeted where they might be toxic.
- Nitrate ester -plasticized polyethylene glycol is used in Trident II submarine-launched ballistic missile solid rocket fuel.
- Dimethyl ethers of PEG are the key component of Selexol, a solvent used by coal combustion, integrated gasification combined cycle (IGCC) power plants to remove carbon dioxide and hydrogen sulfide from the gas waste stream.
- PEG has been used as a gate insulator in an electric double layer transistor to induce superconductivity in an insulator.
- PEG is also used as a polymer host for solid polymer electrolytes. Although not yet in commercial production, many groups around the world are researching solid polymer electrolytes containing PEG to improve their properties and allow other products to be used in batteries, electrochromic display systems and other products. future.
- PEG is injected into industrial processes to reduce foaming in separation equipment.
- PEG is used as a binder in the preparation of technical ceramics.
- PEG is the basis of many skin creams (as cetomacrogol) and personal lubricants (often combined with glycerin).
- PEG is used as a dispersant in a number of toothpastes. In this application, it binds water and helps keep the xanthan gum evenly distributed throughout the toothpaste.
- PEG is also being researched in body armor and tattoos used to monitor diabetes.
- It is used in Hewlett-Packard design jet printers as an ink solvent and lubricant for printheads in low molecular weight formulations (eg PEG 400).