3,6-Dioxaoctanedioic Acid (CAS 23243-68-7): A Versatile Diacid for Polymer and Materials Chemistry

3,6-Dioxaoctanedioic acid is a flexible aliphatic diacid containing two ether linkages within its carbon backbone. This structural feature imparts unique physicochemical properties, including enhanced flexibility, hydrophilicity, and reactivity compared to conventional aliphatic dicarboxylic acids. As a result, it is widely utilized in polymer synthesis, surface modification, and functional material design.

Chemical Identity and Structure

• Chemical Name: 3,6-Dioxaoctanedioic acid
• CAS Number: 23243-68-7
• Molecular Formula: C6H10O6
• Functional Groups: Two carboxylic acids (–COOH), two ether linkages (–O–)

The molecule can be viewed as an ethylene glycol-bridged diacid, where ether oxygens interrupt the carbon chain. This reduces crystallinity and increases molecular flexibility compared to purely aliphatic diacids such as adipic acid.

Structural Features and Reactivity

1. Dual Carboxylic Acid Functionality

• Enables polycondensation reactions
• Participates in esterification and amidation
• Acts as a bifunctional linker in polymer systems

2. Ether Linkages

• Increase chain flexibility
• Improve solubility in polar solvents
• Reduce intermolecular packing

3. Hydrophilic Character

• Promotes water compatibility
• Useful in designing biocompatible or water-dispersible materials

Applications in Polymer Chemistry

3,6-Dioxaoctanedioic acid is particularly valuable as a monomer or co-monomer in advanced polymer systems.

Polyester Synthesis

The diacid reacts with diols to form polyesters with enhanced flexibility and lower glass transition temperatures (Tg).

Polyamide Formation

Reaction with diamines yields polyamides with improved chain mobility and potential for functional modification.

Functional Polymers

The ether-containing backbone contributes to:

• Increased elasticity
• Tunable degradation behavior
• Improved compatibility with hydrophilic systems

Role in Materials Science

Surface Modification and Coatings

The bifunctional nature of the molecule allows it to act as a linker or crosslinking agent, improving adhesion and surface properties.

Biocompatible Materials

Due to its hydrophilic and flexible structure, it is explored in:

• Biomedical polymers
• Drug delivery systems
• Hydrogels and soft materials

Specialty Resins and Additives

It can be incorporated into formulations to adjust:

• Mechanical flexibility
• Moisture affinity
• Processability

Conclusion

3,6-Dioxaoctanedioic acid (CAS 23243-68-7) is a structurally unique diacid combining bifunctional reactivity with ether-induced flexibility. Its ability to modify polymer properties—such as flexibility, hydrophilicity, and processability—makes it an important building block in polymer chemistry, materials science, and emerging functional applications.