Polyurethane Dispersion (PUDS) in Textile Application: Systematic Review

Abstract

Polyurethane dispersions (PUDs) have become an important part of today\'s textile finishing, coating and laminating replacing the conventional solvent based polyurethanes due to rigorous environmental regulations on volatile organic compounds (VOCs). Polyurethane dispersions (PUDs) are colloidal dispersions of polyurethane polymers in water. They have excellent flexibility, high tensile strength, optical clarity, abrasion resistance and tunable breathability. This review offers a detailed look at polyurethane dispersions, covering their basic chemical structure and synthesis, classification based on ionic properties and polyol chemistry, intrinsic physicochemical properties, and methods for their industrial application to textiles. Also, it explores the performance properties of functional garments, technical fabrics and synthetic leather, and the main trends for future bio-based and hybrid compositions.

Introduction

Waterborne Polyurethane Dispersions (PUDs) are environmentally preferable alternatives to conventional solvent-based polyurethane systems used in textile finishing and coating. Traditional polyurethane coatings rely on solvents such as DMF, toluene and MEK, which generate VOC emissions, flammability risks and health concerns. PUDs replace these solvents with water while maintaining desirable polyurethane properties such as elasticity, strength, durability and chemical resistance.

1. Preparation and Raw Materials

PUDs are difficult to disperse in water because polyurethane is inherently hydrophobic. Hydrophilic ionic or non-ionic groups are therefore incorporated into the polymer structure. Major raw materials include:

• Diisocyanates: IPDI, HDI and H12MDI, with aliphatic types preferred for textiles because of their UV and yellowing resistance.
• Polyols: polyester, polyether, polycarbonate and bio-based polyols, which determine flexibility, strength and chemical resistance.
• Internal emulsifiers: DMPA, DMBA, sulfonated diols, tertiary amines or PEG groups.
• Neutralizing agents: such as triethylamine or sodium hydroxide.
• Chain extenders: such as ethylenediamine, hydrazine and 1,4-butanediol.

Important synthesis routes include the prepolymer blend process, acetone process, dispersion-by-fusion method, and ketimine/ketazine method. The prepolymer process is particularly important industrially and involves prepolymerization, neutralization, water dispersion and chain extension.

2. Classification of PUDs

PUDs can be classified according to:

• Ionic character: anionic, cationic, non-ionic and amphoteric.
• Polyol type: polyester-, polyether- and bio-based PUDs.
• Cross-linking: 1K, 2K and hybrid PUD systems.

Anionic PUDs dominate textile applications because of their good mechanical properties, water compatibility and alkaline stability.

3. Properties

PUDs generally have particle sizes of about 10–300 nm, solid contents of 30–50%, tensile strengths of approximately 15–70 MPa, and elongation at break of 200–1000%. Their performance results from microphase separation between hard urethane/urea segments and flexible polyol segments. Hard segments provide strength through hydrogen bonding, while soft segments provide elasticity and flexibility.

A key design challenge is balancing hydrophilicity, which is necessary for water dispersion, with hydrophobicity, which is needed for water-resistant textile coatings.

4. Textile Application Methods

Major application techniques include:

• Knife-over-roll coating: produces continuous protective films for rainwear and technical textiles.
• Foam coating: reduces wet pick-up and preserves softness, breathability and drape.
• Pad-dry-cure: allows PUD particles to penetrate between fibers and improve strength, dimensional stability and crease resistance.
• Transfer coating and lamination: used for synthetic leather, membranes and multilayer technical textiles while reducing or eliminating toxic organic solvents.

5. Major Textile Applications

PUDs are widely used for:

• Breathable waterproof textiles, through microporous or hydrophilic non-porous membranes.
• Eco-friendly synthetic leather, replacing solvent-intensive DMF-based manufacturing.
• Fluorine-free durable water repellents (DWRs), using hydrophobic alkyl chains, PDMS or POSS instead of persistent PFAS chemicals.

Bio-based PUDs incorporating renewable oils such as castor and soybean oil are also being developed to reduce dependence on fossil resources.

6. Future Challenges

Despite their environmental advantages, PUDs still face challenges such as:

• High energy requirements for drying, because water requires substantial energy to evaporate.
• Possible water sensitivity and swelling caused by hydrophilic emulsifiers.
• Need for improved cross-linking and hydrophobic modification.
• Development of increasingly bio-based and renewable raw materials.

Conclusion

The switch to waterborne polyurethane dispersions (PUDs) represents a major leap forward in sustainable textile manufacturing, eliminating the use of harmful organic solvents and VOC emissions, while preserving the mechanical integrity. PUDs offer outstanding tensile strength, flexibility and durability for functional outerwear, zero-VOC synthetic leathers and fluorine-free durable water-repellent (DWR) finishes because to their microphase-separated architecture. PUDs provide tailored solutions for breathable, waterproof and high performance technical textiles with flexible coating, impregnation and laminating processes. Bio-derived polyols, cross-linking strategies and hybrid nanocomposites improvements will improve water resistance and minimize drying energy requirements, making PUDs a key component in sustainable textile manufacturing.

References

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Copyright

Copyright © 2026 Lolla Renuka Tejaswini, Ayodya Kavitha. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.