Methoxypolyethylene Glycol CAS 9004-74-4

It is precisely this "golden oil" like physicochemical property that enables polyethylene glycol monomethyl ether to deeply penetrate into more than ten fields such as construction, medicine, cosmetics, textiles, electronics, rubber, pesticides, energy storage materials, etc. The core driving force behind the difference in their uses lies in the difference in molecular weight - low molecular weight products have high water solubility, low viscosity, and are suitable for permeation and short-term dispersion; High molecular weight products have high viscosity and strong slump retention, making them suitable for thickening and long-term modification.

The core role in the field of construction is the key raw material for cement high-efficiency water reducing agents and reinforcing agents, which is also the most widely used and industrialized application direction.
Its mechanism of action is very clear: it undergoes copolymerization reaction with monomers such as acrylic acid to generate polycarboxylate superplasticizer. In this process, the segments of methoxypolyethylene glycol are adsorbed on the surface of cement particles, and the particles are fully dispersed through steric hindrance effect, thereby significantly reducing the amount of water used in mixing and improving the fluidity, early strength, and durability of concrete.

The polycarboxylate superplasticizer synthesized from this raw material has six major advantages, including low dosage, high water reduction rate, good reinforcement effect, excellent durability, non rusting of steel bars, and environmental friendliness.

The choice of molecular weight directly determines the performance bias of water reducing agents. Low molecular weight products such as MPEG-600 have synthesized water reducing agents with fast dispersion speed but weak slump retention, making them suitable for short-term construction needs; Medium molecular weights such as MPEG-1000 and MPEG-2000, with both dispersibility and slump retention, are the most commonly used specifications;

High molecular weight materials such as MPEG-4000 have excellent slump resistance and are suitable for long-distance transportation or large volume concrete engineering, but the initial dispersion effect is slightly slow. In practical engineering, the large monomer MPEGMA synthesized from MPEG-1000 and methacrylic acid can be copolymerized with sodium methacrylsulfonate to produce a ternary copolymer polycarboxylate superplasticizer. When the dosage is only 0.33%, the initial flowability of cement paste can reach 284mm, and the 28 day concrete strength reaches 45.8MPa, with excellent performance. 

The depth and breadth of application in the pharmaceutical field are the most technologically advanced sectors among all its uses.
Firstly, drug PEGylation modification. This is the core pharmaceutical application of mPEG. By utilizing the hydroxyl group (or activated functional groups such as carboxyl and succinimide ester) at the end of mPEG to covalently bind with active groups (such as amino and thiol groups) in drug molecules, "PEGylation modification" can be achieved. This modification can significantly improve the physicochemical properties of drugs.

Such as prolonging drug half-life (reducing metabolic clearance), reducing immunogenicity, improving water solubility and bioavailability. Classic cases include PEGylated interferon, PEGylated insulin, etc., which have been widely used in clinical practice. Compared to ordinary PEG with hydroxyl groups at both ends, the single terminal inert methoxy group of mPEG can avoid crosslinking between carriers or drug molecules, reduce the complexity of polymerization products, improve modification efficiency and product uniformity, making it more suitable for pharmaceutical applications.

Secondly, drug delivery systems. MPEG can serve as a carrier for controlled release drug delivery systems, improving drug stability and solubility, and prolonging drug retention time in vivo. It is often used as a drug loading material or combined with drugs to form a controlled release system. By utilizing its hydroxyl terminal reactivity, mPEG can copolymerize with other monomers, introduce hydrophilic segments, and construct nanocarriers such as micelles, liposomes, and nanoparticles to optimize drug delivery processes. The current research focus is on "targeted PEGylation" and "intelligent responsive PEGylation carriers" (such as pH sensitive and reduction sensitive mPEG copolymers) to achieve targeted drug release.

Thirdly, biomaterials and tissue engineering. MPEG can form hydrogels, polymer networks and other support materials, which are commonly used in cell engineering and tissue engineering. Due to its excellent biocompatibility, mPEG can serve as a substrate for cell growth, promoting cell adhesion, growth, and proliferation. High molecular weight mPEG (such as MPEG-10000) can be used to prepare biodegradable scaffolds and hydrogels. Its long chain structure can enhance the flexibility and stability of materials, while reducing non-specific adsorption with human cells.

Fourth, PROTAC Linker. In cutting-edge cancer research, mPEG can serve as a PROTAC linker for synthesizing protein degradation targeted chimeric (PROTAC) molecules. This application elevates mPEG from a traditional excipient to the core material level of innovative drug development.

Fifth, surface modification of medical devices. By coating mPEG on the surface of medical devices, the wettability and biocompatibility of the material can be improved, the surface hydrophilicity can be enhanced, protein adsorption and immune response can be reduced, which is of great significance for implantable devices and drug carriers.

Toxicological data shows that polyethylene glycol is a polymer derived from the hydrolysis of ethylene oxide, which is non-toxic and non irritating. The oral LD50 of rats is 22 mL/kg, and the LD50 of rabbit skin is greater than 20 mL/kg. Low molecular weight polyethylene glycol has relatively high toxicity, but the overall toxicity of diols is quite low. However, it should be noted that high-dose oral administration may cause diarrhea, and when the concentration of polyethylene glycol 300 in the injection exceeds 40% (V/V), hemolysis may occur. Local mucosal administration may cause irritating pain.

In the fields of cosmetics and personal care, the application of polyethylene glycol monomethyl ether covers a full range of products from low molecular weight to high molecular weight, with its core functions being thickening, lubrication, moisturizing, and stable formulation.

Low molecular weight products (such as MPEG-400 and MPEG-600) have excellent water solubility and can be used as humectants in cosmetics, essence, shaving cream and other products to increase the skin's moisture. Medium molecular weight products (such as MPEG-1000, MPEG-2000) have both lubricity and consistency adjustment capabilities, and are used in lotion, face cream, toothpastes, etc. to reduce the stickiness of products.

High molecular weight products (such as MPEG-4000) are used as thickeners for lipstick, deodorant stick, soap, foundation make-up, etc. to improve the hardness and stability of products and prevent ingredients from layering.

In topical cleansers, mPEG can increase skin flexibility and has a moisturizing effect similar to glycerol. Its excellent surface activity also allows it to be used as a wetting agent, emulsifier, and stabilizer, playing a versatile role in cosmetic formulations.

Polyethylene glycol monomethyl ether is mainly used as a thickener and lubricant in the textile printing and dyeing industry. Low molecular weight products (such as MPEG-400) have strong permeability and are suitable as printing and dyeing auxiliaries for fine fabrics; Medium molecular weight products (such as MPEG-1000) have better lubricity and can effectively reduce the breakage rate as spinning lubricants for textile fibers. By utilizing its lubricity and water solubility, mPEG can reduce fiber friction damage, while helping dyes penetrate evenly and improving printing and dyeing quality.

The terminal hydroxyl group of mPEG has high reactivity and can copolymerize with other monomers, introducing hydrophilic segments to improve the material's water solubility, flexibility, or biocompatibility. Low molecular weight mPEG (such as MPEG-500, 750) is used for synthesizing non-ionic surfactants, and its short chain structure can balance the lipophilic/hydrophilic ratio; Medium and high molecular weight mPEG (such as MPEG-2000, 10000) is used to synthesize hydrogels, polyurethane and other materials. The swelling rate and mechanical properties of the materials are controlled by adjusting the MPEG chain length.

In the field of energy storage materials, the application of methoxypolyethylene glycol is rapidly rising. Phase change energy storage materials can be prepared by grafting mPEG onto cellulose acetate, with a grafting rate of up to 129% to 224%, a maximum phase change enthalpy of 102.52 J/g, and stable morphology above the melting point without melting leakage. The blended solid solid phase change energy storage material with mPEG as the phase change material and PET as the skeleton has the highest yield when the PET/MPEG mass ratio is 40:60. In the field of lithium-ion batteries, maleic acid mono polyethylene glycol mono methyl ether ester can be used as a slurry dispersant and has good compatibility with graphite negative electrodes.

MPEG can be used as a suspension agent and thickener in industrial cleaning agents. In the field of metal processing, it is a molding agent, lubricant for metal drawing and stamping, as well as a cooling and lubricating component for cutting fluid and grinding fluid. Used as a lubricant in the paper industry and as a lubricant and masterbatch additive in PVC processing. It also has extensive penetration in fields such as electroplating and wastewater treatment.

MPEG can be used as polyethylene glycol monomethyl ether ester in pesticide formulations to enhance the dispersibility and stability of pesticides. In the field of electronics, it can be used as a component of high boiling point hydraulic brake fluid and as a hydrophilic coating on the surface of electronic devices.