Polyurethane synthetic leather is a new multi-purpose composite material that has developed rapidly in recent years. It is made on the basis of coating polyurethane slurry with open cell structure on the low base of textile and non-woven fabrics. However, most of the polyurethanes used are solvent based, and the harm to the environment and human body caused by DMF residue and VOC volatilization in the production process has become a technical bottleneck restricting the development of the industry. At present, water-based polyurethane is an ideal substitute for solvent based polyurethane, but its defects are low solid content, poor physical properties, easy adhesion on the coating surface, poor hydrolysis resistance, slow volatilization in the coating production process, and low production efficiency.
Based on the concept of "green and environmental protection" and improving the added value of products, the project has developed a set of new technology system for the production of high solid and aqueous polyurethane and ecological synthetic leather that can replace solvent polyurethane. The high solid content waterborne polyurethane designed and developed can reduce DMF residue and VOC volatilization from the development source while improving the coating performance. At the same time, because the film contains a large number of hydrophilic groups and microporous structures, the coating has good air and moisture permeability, and is a real production product. In addition, polyurethane is modified with nano materials to develop high-performance and multi-functional polyurethane synthetic leather products suitable for market demand, so as to improve the added value of products and strengthen market competitiveness.
Main research contents:
(1) Preparation technology of high solid content waterborne polyurethane. According to the mathematical model of bulk density of spherical objects, a high solid content aqueous polyurethane with multi-dimensional particle size distribution is prepared. The multi-dimensional particle size distribution can improve the solid content of lotion without increasing the viscosity too high. The problem of high viscosity and low solidity in the production of high content waterborne polyurethane is solved. The solid content is > 50%, the contact angle of the film is 101.1 °, and the water resistance and hydrolysis resistance are improved.
(2) Manufacturing technology of waterborne polyurethane foamed bass. Based on the high solid content aqueous polyurethane, the combination of physical and chemical foaming methods is selected to create the water-based polyurethane bass with adjustable cell. The product is plump, thick and soft, with good moisture absorption and permeability, achieving zero VOC and DMF emissions in the production process, reducing the difficulty of end treatment and saving the cost of solvent recovery and treatment in the later stage.
(3) Preparation technology of functional waterborne polyurethane. Multifunctional waterborne polyurethane with super hydrophobicity, wear resistance and anti-static properties has been prepared by using the click reaction mechanism of "mercapto monoene", nanotechnology and light curing technology. It can be used in synthetic leather, textile coating, oil-water separation, electromagnetic shielding and other fields.
Post time: Sep-13-2022