Overview and development of waterborne PU and curing agent

发布时间:

2025-03-31

Polyurethane is a type of polymer material containing repeating carbamate structural units. The organic solvents contained in traditional solvent-based polyurethane are flammable, explosive, and toxic, which have adverse effects on the human body and the environment. With the enhancement of people's environmental awareness, water-based polyurethane materials have gradually received attention.

Water-based polyurethane uses water as a dispersion medium, and has the advantages of being non-flammable, environmentally friendly, non-toxic, and safe. It has been widely used in coatings, adhesives, synthetic leather, elastomers, building materials, fabric finishing, polymer surfactants and other fields. Water-based polyurethane is divided into single-component water-based polyurethane and two-component water-based polyurethane.

Single-component water-based polyurethane does not need to add a cross-linking agent to obtain the required performance, but due to its linear structure, low cross-linking degree, and hydrophilic groups in the molecule, it has certain defects in hardness, water resistance and solvent resistance, and its application range is limited; while the two-component water-based polyurethane has a high cross-linking density, and has excellent mechanical properties such as high film hardness, good wear resistance, and strong adhesion, as well as chemical properties such as water resistance and solvent resistance. To a certain extent, it makes up for the shortcomings of single-component water-based polyurethane and can be used as a high-end material, which is the development trend of water-based polyurethane.

Two-component waterborne polyurethane is mainly composed of a hydroxyl-containing polyol component and an isocyanate-containing (NCO) waterborne curing agent component. As an important component of waterborne polyurethane, the composition and structure of the waterborne isocyanate component determine the physical and mechanical properties, weather resistance, medium resistance and other chemical properties of waterborne polyurethane. Therefore, the research on waterborne polyurethane curing agent is the key to the substantial application of waterborne polyurethane.

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