Synthetic Leather Finishing Agent: The Synthesis And Application Of Waterborne Polyurethane

Leather products have soft, wear-resisting, high strength, high moisture absorption andwater vapor permeability (comfort) and many other advantages, and welcomed by the people.With the rapid development of economy and the urgent demand of ecological environmentprotection, Natural leather has been unable to meet the needs of people’s lives. Synthetic leathercan imitate the physical structure and use performance of natural leather; it is gradually replacingthe application of natural leather on the market, and it will be a big trend in the development ofleather industry. Because of people’s aesthetic about the cosmetic requirements for syntheticleather is different, therefore, the synthetic leathercoating agent emerged.Polyurethane is a kind of extremely widely used polymer materials. It can achieve thedesired optimum mechanical properties, by selecting the structure and ratio of the soft segmentand hard segment. As a new environmentally friendly Emulsion, Aqueous polyurethanedispersion emulsion combined polyurethane coating high Stiffness, adhesion, corrosionresistance, solvent resistance and good low VOC content of the aqueous emulsion, it had moreand more attention ofthe researchers in recent years.Compared with conventional polyurethane emulsion, Experiments in order to ensure thatproducts have a large molecular weight, choose the larger molecular weight of polyether polyolsas raw materials; we used pentaerythritol which has containing4hydroxyl groups to replace–DMPA which is the best industrial production expanding linking agent now. It can Increase thedegree branching of the products; improve the performance of the product after application. Inorder to improve the environmental performance of the product, Experiments selected differentsolvents. Ultimately determine the acetone as the solvent to replace the DMF.In the application, because the molecular weight large enough, its extinction outperformstraditional polyurethane emulsion, therefore the amount of matting is less than traditionalpolyurethane emulsion. It can greatly reduce the cost of production, and increase theenvironmental performance of synthetic leather applications.The first part of this paper studied the impact of product molecules,such as the synthesisreaction temperature, reaction time, catalyst, molecular weight, R value, the degree of cross linking. At the same time the product has been tested to observe trends in different conditionsaffect the performance of the product, obtained molecular structure affect the relationshipbetween the performance of the product, and ultimately find the optimal synthesis conditions,synthetic a good performance product..In this paper, the second part is to study the influence of the product applicationperformance, including coating amount, R value, the baking temperature and time, formulationratio, and so on. Experiments carried out the compounded through product, find the optimalprocess conditions. While also determined the effect of the application to determine theapplication results.