Industrial-grade 99% Poly(ethylene glycol) dimethacrylate CAS 25852-47-5

 What is PEGDMA? How does it work?

PEGDMA, short for Poly(ethylene glycol) dimethacrylate, is a bifunctional monomer with a methacrylate double bond at each end and a polyethylene glycol segment in the middle. Its CAS number is 25852-47-5. At room temperature, it is a transparent, viscous liquid that can undergo free radical polymerization under light or heat initiation, weaving the flexible polyethylene glycol segments into a cross-linked network. It is this "reactive at both ends and flexible in the middle" structure that makes it a common cross-linking monomer in UV-curable coatings and inks, 3D printing resins, dental restorative materials, hydrogels, and rubber vulcanization systems.

Basic information : Chinese name: Poly(ethylene glycol) dimethacrylate; English name: Poly(ethylene glycol) dimethacrylate (abbreviation: PEGDMA); CAS number: 25852-47-5; Molecular formula: CH2=C(CH3)COO(CH2CH2O)nCOC(CH3)=CH2 (n is the number of ethylene glycol units); Molecular weight varies with n, approximately 200-8000, commonly 300-800; It is a transparent viscous liquid at room temperature, with no fixed melting point, and the double bonds can self-polymerize under heat or ultraviolet light (commercial products usually contain MEHQ polymerization inhibitor); Synonyms: PEGDMA, Polyethylene glycol dimethacrylate, α,ω-dimethacryloyloxy polyethylene glycol, etc.

Structurally , the molecular backbone of PEGDMA consists of three parts: methacrylate groups (CH2=C(CH3)COO-) at both ends, ester bonds, and a polyethylene glycol segment (-CH2CH2O-)n in the middle. Each molecule contains two carbon-carbon double bonds, which are the active sites for polymerization. The polyethylene glycol segment in the middle is composed of repeated ethylene glycol units. The segment length n determines the molecule's hydrophilicity, flexibility, and molecular weight. The smaller the n, the shorter the molecule and the lower the viscosity; the larger the n, the longer the molecular chain and the stronger the hydrophilicity. The bifunctional structure allows PEGDMA to both self-polymerize and copolymerize with monomers such as acrylates, acting as a "bridge" in the reaction to connect linear polymer chains into a three-dimensional network.

physical properties , PEGDMA is mostly a colorless to light yellow transparent viscous liquid at room temperature. The viscosity increases significantly with the increase of molecular weight, and high molecular weight grades are waxy semi-solids. It is soluble in most organic solvents such as acetone, ethanol, toluene, and ethyl acetate. The hydrophilicity increases with the length of polyethylene glycol segments. The density is about 1.0-1.1 g/cm³. It is sensitive to light and needs to be stored in a light-proof and sealed container. Polymer inhibitors such as MEHQ are usually added to the product to prevent self-polymerization during storage.

Chemically , PEGDMA is a bifunctional methacrylate monomer: the double bonds at both ends can be rapidly opened under the action of photoinitiators or thermal initiators and undergo free radical polymerization and copolymerization, which is the basis of all its applications; the double bonds are sensitive to ultraviolet light and heat, and the storage period relies on polymerization inhibitors to maintain stability; the ester bonds in the molecule can be hydrolyzed under strong acid and strong base conditions; the cross-linked network formed after polymerization is chemically stable, water-resistant and solvent-resistant, and can exhibit a continuous change from hydrophobic hard to hydrophilic soft depending on the proportion of polyethylene glycol segments.

Why does PEGDMA play these roles in fields such as photopolymer materials, 3D printing, dental materials, and energy materials? Its mechanism of action mainly includes the following:

Double-bond free radical polymerization crosslinking mechanism : The methacrylic acid double bonds at both ends of PEGDMA open and connect with each other under the initiation of light or heat, weaving individual monomer molecules into a three-dimensional network, and the material instantly transforms from a liquid into a solid molded body - this is the core action of all its applications.

Bifunctional network bridging mechanism : Each PEGDMA molecule carries two reactive double bonds, which can simultaneously connect to two polymer chains, acting as a "bridge" in the copolymerization system to connect the originally linear acrylate chains into a network. As the crosslinking density increases with the amount added, the material's rigidity, solvent resistance, and dimensional stability are enhanced.

Polyethylene glycol segment regulation mechanism : The length of the middle polyethylene glycol segment can be adjusted. When n is small, the network is dense and hard, while when n is large, the network is loose, flexible and absorbent. By selecting different molecular weight grades, the material properties can be continuously adjusted between hard coatings and soft hydrogels.

Photopolymerization rapid prototyping mechanism : In the presence of a photoinitiator, the double bonds of PEGDMA are polymerized within seconds by ultraviolet light or LED light irradiation, which enables the coating, ink and 3D printing resin to be cured layer by layer rapidly, achieving high-precision and high-efficiency molding processing.

Hydrophilic gel formation and biocompatibility mechanism : Polyethylene glycol segments are hydrophilic and biocompatible. After cross-linking, they can absorb a large amount of water to form hydrogels, which is the basis for its role in contact lenses, wound dressings and tissue engineering.

All Uses of PEGDMA

1. UV-curable coatings and inks

UV-cured coatings (wood coatings, plastic coatings, paper varnishes)

It cures within seconds of being exposed to ultraviolet light, forming a high-hardness, wear-resistant coating.

Corresponding products: UV wood coatings, plastic topcoats, varnishes, etc.

UV printing inks

Instant curing and solvent-free evaporation make it suitable for high-speed printing.

Corresponding products: UV inks, screen printing inks, flexographic inks, etc.

2. Adhesives and sealants

UV-curable adhesives

It can be used to bond electronic components, glass and metal, with fast curing and high bonding strength.

Corresponding products: UV adhesives, optical adhesives, electronic encapsulation adhesives, etc.

Radiation-cured pressure-sensitive adhesive

Crosslinking improves cohesive strength and enhances temperature and weather resistance.

Corresponding products: UV-curable pressure-sensitive tape, label adhesive, etc.

3.3D Printing and Additive Manufacturing

SLA/DLP photosensitive resin

Layer-by-layer photocuring molding ensures high precision and is used for dental models, precision parts, and figurines.

Corresponding products: SLA resin, DLP resin, dental printing resin, etc.

Bioprinting hydrogel ink

Cell-printed tissue engineering scaffolds.

Corresponding products: bioprinting inks, tissue engineering scaffolds, etc.

4. Optical Materials

Optical coatings and functional films

UV-cured optical coatings improve abrasion and scratch resistance.

Corresponding products: optical film coatings, anti-fog coatings, etc.

5. Rubber and Elastomer Industry

Peroxide vulcanizing agent

When used in combination with peroxides, it increases the crosslinking density and improves heat resistance and mechanical properties.

Corresponding products: EPDM seals, NBR hoses, silicone rubber products, etc.

6. Battery and Energy Materials

Gel polymer electrolyte

Cross-linking forms a three-dimensional network to adsorb electrolyte, which is used in lithium-ion batteries.

Corresponding products: gel polymer electrolyte membranes, solid-state battery electrolytes, etc.

7. Functional Materials and Research Fields

Microfluidics and Separation Membranes

Polyethylene glycol crosslinked hydrogels are used in microfluidic chips and porous filter membranes.

Corresponding products: microfluidic chips, porous separation membranes, etc.

Composite materials and surface modification

It is used as a resin matrix modifier to improve interfacial wetting and toughness.

Corresponding products: modified resins, composite matrix, etc.

 Summary

PEGDMA (polyethylene glycol dimethacrylate, CAS 25852-47-5) is a bifunctional crosslinking monomer with a methacrylate double bond at each end and a polyethylene glycol segment in the middle. The double bonds at both ends allow it to polymerize rapidly under light or heat initiation, connecting linear chains into a three-dimensional network, while the polyethylene glycol segment in the middle allows it to be freely adjusted between rigid coatings and flexible hydrogels. It is this combination of "reactive ends and flexible middle" that makes it ubiquitous, from UV coatings and inks to 3D printing resins, rubber vulcanizing agents, and battery electrolytes. Understanding its double bond and segment structure is key to understanding why it has become a long-standing crosslinking monomer in photocuring.