Issue 28/2015 - Qingdao Energy Institute has developed environmentally friendly one-component polyurethane waterproofing coatings

Recently, the bio-based and biomimetic polymer team led by Wan Xiaobo, a researcher at the Key Laboratory of Bio-based Materials of Qingdao Institute of Bioenergy and Process Research, Chinese Academy of Sciences, has made new progress in polyurethane building waterproof materials, successfully developed two types of environmentally friendly one-component polyurethane waterproof coatings, and has successfully achieved pilot test and engineering demonstration
.

At present, one-component polyurethane waterproof coatings have become the development direction of polyurethane waterproof coatings because of their advantages of simple construction, but there are still problems such as large area consumption, the need to use a large amount of organic solvents, and the need to paint many times
.
At present, Mu Youbing, assistant researcher of the bio-based and biomimetic polymer team, has successfully developed two types of polyurethane waterproof coatings with high tensile strength and high elongation at break through the careful design of the molecular structure of polyurethane resin, adjusting the arrangement of segments in the polymer and the density of functional groups, and has successfully achieved pilot test and engineering demonstration
.
One of the coatings is an environmentally friendly solvent-free one-component polyurethane coating (type I), which has good water dispersion performance, mixed with water and sprayed on the surface of the substrate, and after drying, it can form a film
with elongation at break greater than 1200% and tensile strength of more than 2.
5 MPa.
The other type of coating is a fully hydrophobic solvent-free one-component polyurethane coating (type II), which can be sprayed directly on the surface of the substrate and cured under appropriate humidity, and the resulting film has excellent adhesion to the surface of the substrate, with elongation at break greater than 2500% and tensile strength of more than 9 MPa
.

The polyurethane waterproof coating has a unique waterproof mechanism: Type I polyurethane coating uses water as a curing agent, which is environmentally friendly and non-toxic, and has a high degree of safety
.
And because of its small viscosity, it can effectively penetrate into the concrete to form an interpenetrating network structure, seal and block the internal defects of concrete, not only play a waterproof and impermeable effect, but also enhance the strength of
concrete.
The infiltration of waterproof coatings can effectively integrate the waterproof layer with the base concrete, overcome the phenomenon of water channeling between layers, and reduce the chance of water leakage caused by surface scratches of traditional waterproof
coatings.
During construction, type I polyurethane coating can be sprayed and then type II polyurethane waterproof coating
can be sprayed.
Because type II polyurethane coating has excellent surface adhesion, wear resistance, water resistance and hydrolysis resistance, it can effectively protect the waterproof base layer, prolong its service life, and achieve a durable effect
.

Due to the unique waterproof mechanism, the combination of these two types of coatings can achieve a good waterproof effect
under the condition of a small total spraying amount.
Compared with traditional one-component polyurethane waterproof coatings, the dosage is less and the cost of use is low; The spraying construction method is adopted, and the labor cost is low; Less use of organic solvents, more environmentally friendly
.
Therefore, it has broad market prospects
.
(Surplus)