The compatible analysis of asphalt polyurethane waterproof coating

China Paint Online News Information: The polarity of asphalt is very small, and polyurethane pre-polymer because it contains polar group aminomate ethyl and -O-base, has a strong polarity, the compatibness of the two is poor. Performance in the material, for easy oil or solid liquid separation is incompatible, resulting in poor mechanical performance, waterproof performance is reduced. This problem is a difficult problem in the study of asphalt polyurethane waterproof coating. At present, the domestic mainly by adding a compatible agent to increase the compatible between asphalt and polyurethane.1, the choice of compatible agent the choice of compatible agent should be considered from the structure, polarity, boiling point and relative molecular mass. First, it should help the asphalt dissolve in the polyurethane solvent, and secondly, it should be appropriately soluble or reactive with polyurethane. The most suitable compatible agent is a surfactant material consisting of a basic non-polarity part and a polar part, the structure is: CH3 one (CnH2n) one Rl, of which n≥4, Rl is COOH, COOM or COOR2, etc.; Its basic non-polar part is generally compatible with asphalt material, and the longer the chain, the less compatible agent is required; Therefore, the compatible agent makes the asphalt material suspended in the pre-cluster, making it easy to mix them all, without the asphalt being pre-empted.2, compatibility evaluation asphalt polyurethane compatibility can be divided into initial compatibility and plastic compatibility. Initial compatible is whether nails and B-parts can form an equal system after full mixing and mixing. If the initial compatible is good, can form an equal system, then the coating film can be normal curing, with a certain degree of physical and mechanical properties. Initial compatible can be judged by lead experiments. After mixing the A and B parts 3-5min, use the glass rod to lift the material from the glass surface, to see the length of the continuous fine line can be pulled out. The better compatible, the longer and thinner the lead.A, B composition mixing of the initial stage, the system has a good initial compatible, can also form a homogeneity system, but with the curing process, small molecular mass polyurethane prepolymer by chemical reaction gradually crosslinked into a polymer of high molecular mass, and has a certain strength and elasticity, in the process, the chemical structure has undergone a qualitative change.plasticization compatible means that after complete curing, whether the system is still uniform, compatible agents, asphalt and other parts can play an effective role in the following polyurethane ontester in a highly compatible state. Plastic compatible can be evaluated by directly observing the mixing uniformity of the mixture of asphalt in polyurethane before and after the use of the compatible agent by electron microscope.