Synthesis And Study On Single Component Pu Waterproofing Coatings Cured By Moisture

Urban residential water storage tanks a long time, odor, rust, algae, red worm often appear in the box, these resulting deterioration in water quality and secondary security risk. Single-component polyurethane coatings have a wide range of construction and excellent performance, so they are applicated in a variety of building waterproofing fields. The promising coatings are attributed to the fact that the pollution-free product makes they can be used for drinking water. It will be a special significance through the development and performance testing of the paint. That includes preventing secondary pollution of drinking water, protecting its safety, and opening up a new application world of the polyurethane coatings.A single-component moisture-curing polyurethane waterproofing coating was synthesized after research. The factors that affect the basic performance were comprehensively analysed. The best synthesis conditions and processes were obtained through single factor experiments and orthogonal experiment. They were as follows: nNCO/nOH 4:1, N-220/N-330 mass ratio of 9:1, filler content of 25%, defoamer silicone and CaO 0.28% respectively, catalyst content of 0.3% ~ 1%, reacting in a appropriate stirring speed 65 ~ 70℃for 1.5 ~ 2.5h, then adding the auxiliary and mixing it up for material. It had integrated performance, good adhesion, no bubbles and pinholes after cured. The basic physical and chemical properties of the coating were reach or above the GB / T 19250-2003 via testing.The application performance such as anti-rust, anti-algae, anti-worm and possible mechanisms of the coating were studied. It showed that the coating in the water had good anti-rust and some anti mildew, algae, bloodworm effects. Besides, nNCO/nOH, N-220/N-330, filling content were of great impact, while other factors were not so significant.Group structure, curing reaction process, as well as micro-structure and morphology of films which had different characteristics were tested by infrared (IR) and scanning electron microscopy (SEM), many possible reasons which cause coatings to deteriorate were discussed.