The Synthesis And Properties Of Single-component Waterborne Polyurethane

Polyurethane is a very extensive class of polymers. Composition and structure can be varied within wide limits, consequently there is no definite property pattern. All polyurethane, however, are made by the same general principle. In spite of the multitude of aspects and features products base on the macromolecular polyurethane and the most versatile property patterns which can be tailor-made for the widest variety of applications, these products are chemically all very similar.Waterborne polyurethane dispersions are popular because they are non-toxic, non-flammable and do not pollute air or water, at the same time, which can meet very demanding performance requirements. At present waterborne polyurethane coatings have been widely used in fabric finish, leather finish, high quality building coatings, coatings of wood and furniture .etc..In this paper aqueous dispersions of anionic polyurethane(APU) were prepared using polyester and polyol. Based on the polyol waterborne polyurethane we carried out the modification by cross chain reagent.Firstly, the synthesis techniques was fully researched with a series of parallel experiments test. The factors were considered, such as the method of preparation, the pretreatment to the raw materials, the temperature, the dosage of the catalyst. The relationship between the factors above and the sample's properties was researched.According to the present information about it, the effect factors were obtained. The two series of polyester waterborne polyurethane were prepared. The impact of the dosage of DMPA to the properties of the waterborne polyurethane latex, and the film of rate of elongation, tensile-strength , water resistance was researched. We also considered the extent of neutralization and the ratio of TDI and PBAGDuring the process of modification, we prepared a series of modified APU using the TMP which contains three function groups. The content of the TMP is the key factor which effects the properties of the APU. The ratio of NCO/OH was also researched in the aspect of the film's mechanism properties.Finally, based on the comparison and analysis, we obtained the optimal prescription and the reaction condition which provides the theories for industrialization.