Preparation and performances of cationic waterborne polyurethane coating co-modified with acrylic and amino acid

Acrylic acid is commonly used to modify anionic waterborne polyurethanes, and little research has been done on the modification of cationic waterborne polyurethanes. In this study, the effect of acrylic acid addition at different levels on the performance of cationic waterborne polyurethanes was investigated. The experimental results showed that the stability, and chemical resistance of cationic waterborne polyurethane coatings were improved with the addition of acrylic acid, which has the advantages of better chemical resistance, high stability and low price, and the hardness of the coating gradually increased and the adhesion decreased with the increase of acrylic acid content, therefore, the acrylic acid content of 21% was the most suitable. In addition, the effect of amino acids as neutralizing agents on the performance of cationic waterborne polyurethane coatings was also explored. The addition of amino acids helped the cationic waterborne polyurethane to form a reticular crosslinked structure, and the experimental results showed that the mechanical properties of the cationic waterborne polyurethane coatings were greatly improved. Compared with the commonly used acids (hydrochloric acid and acetic acid), amino acids have the advantage of being environmentally friendly and non-toxic, which is more conducive to the industrial production and application of cationic waterborne polyurethane coatings.