The 6 characteristics of water-based polyurethane are as follows:

Most water-based polyurethane adhesives do not contain -NCO groups, so they mainly rely on the polar groups within the molecules to generate cohesive forces and adhesive forces for curing. Solvent-based or solvent-free one-component and two-component polyurethane adhesives can fully utilize the reaction of -NCO to enhance the bonding performance during the bonding and curing process. Water-based polyurethane contains carboxyl and hydroxyl groups, which can participate in reactions under suitable conditions to make the adhesive cross-link.

In addition to added polymer thickeners, important factors that affect the viscosity of water-based polyurethane include ion charges, core-shell structure, and emulsion particle size. The more ions and counterions （free ions in the solution that are opposite in polarity to the ion groups contained in the main chain and side chain of polyurethane） there are on the polymer molecules, the higher the viscosity. The influence of factors such as solid content （concentration）, molecular weight of polyurethane resin, and cross-linking agent on the viscosity of water-based polyurethane is not significant, which is conducive to the high molecular weight of polyurethane to improve the cohesive strength of the adhesive. In comparison, the main factors affecting the viscosity of solvent-based polyurethane adhesives are the molecular weight of polyurethane, branching degree, concentration of the adhesive, etc. At the same solid content, the viscosity of water-based adhesives is smaller than that of solvent-based adhesives.

Viscosity is an important parameter for the performance of adhesives. The viscosity of water-based polyurethane is generally adjusted by water-soluble thickeners and water. Solvent-based adhesives can be adjusted by increasing the solid content, molecular weight of polyurethane, or choosing appropriate solvents.

Due to the poorer volatility of water than organic solvents, water-based polyurethane adhesives dry more slowly, and due to the large surface tension of water, their ability to wet hydrophobic substrates is poor. If most of the water has not evaporated from the bonding layer or coating into the air, or has been absorbed by porous substrates during heated drying, it is difficult to obtain a continuous layer of adhesive.

Perekat poliuretan berbahan dasar air dapat dicampur dengan berbagai resin berbahan dasar air untuk meningkatkan kinerja atau mengurangi biaya. Pada saat ini, perhatian harus diberikan pada sifat ionik dan keasaman dan kebasaan perekat berbasis air ionik, jika tidak, kondensasi dapat terjadi. Karena pengaruh kompatibilitas antara polimer atau kelarutan dalam pelarut tertentu, perekat poliuretan berbasis pelarut hanya dapat dicampur dengan perekat resin lainnya dalam jumlah terbatas.

Perekat poliuretan berbasis air memiliki sedikit bau, pengoperasian yang mudah, dan pembuangan residu yang mudah, sedangkan perekat poliuretan berbasis pelarut terkadang membutuhkan konsumsi pelarut dalam jumlah besar selama penggunaan, dan proses pembersihannya tidak senyaman perekat berbasis air. .

Solusi untuk masalahperekat poliuretan yang ditularkan melalui air debonding: Perekat poliuretan berbasis air banyak digunakan dalam bidang perekat dan berkelompok interior otomotif, seperti kotak sarung tangan, kotak penyimpanan, dan kotak sandaran tangan tengah. Namun pada bagian interior otomotif, material PP banyak digunakan. Karena sifat non-polar bahan PP, sulit untuk merekatkan permukaan, dan masalah seperti debonding antara substrat PP dan perekat poliuretan berbahan dasar air sering terjadi. Solusi yang efektif adalah dengan melakukan pretreatment pada permukaan bahan PP, menerapkan lapisan agen perawatan PP antara substrat dan perekat untuk meningkatkan kekuatan ikatan, dan menyelesaikan masalah ikatan dan debonding yang tidak dapat diandalkan.