Polyurethane epoxy slurry successfully developed

Polyurethane epoxy resin, which combines the advantages of epoxy and polyurethane, has been successfully developed by the Department of Chemistry of Shangqiu Normal University and the Department of Light Industry and Chemical Engineering of Shandong Institute of Light Industry. The product has high compressive strength, bonding strength, and pull strength. Tensile strength and a certain degree of elongation are suitable for fracture grouting of concrete and bedrock.
Concrete (or reinforced concrete) is a non-homogeneous brittle material that is prone to cracks. Grouting is the most important method for internal reinforcement of concrete cracks, and grouting is intended to restore the structural integrity and design application status. Polyurethane (non-water soluble) is easy to diffuse, has good impregnability, strong adhesion to concrete and various materials, good elasticity of the consolidated body, high impact strength, but the viscosity of the prepolymer is high Reactive diluents are difficult to find, and at the same time, they are easy to foam. Compression and tensile properties of consolidated bodies are not as good as those of epoxy sizing materials, and they are more used as impervious plugging grouting materials.
Epoxy resin has high bonding strength, good stability, and no complicated construction. However, epoxy resin itself is a rigid material with inherent net brittleness, high elastic modulus, and low elongation, when the adhesive surface is stressed. Cracks will soon spread, causing the cracks to crack. A new grouting material-polyurethane epoxy resin material, which is obtained by grafting a polyurethane onto an epoxy resin molecule, overcomes the disadvantages of the polyurethane slurry that has no reactive diluent and low strength, and overcomes the disadvantages of the epoxy paste. The shortcomings of brittle material.
It is reported that the main raw materials of polyurethane epoxy resin are epoxy resin, polyether polyol, polyisocyanate, aliphatic polyamine, aromatic polyamine, reactive diluent, catalyst, reaction rate modifier. In the synthesis process, the polyurethane is first grafted onto the epoxy resin molecule to obtain a polyurethane epoxy resin. Because the polyurethane epoxy resin molecule contains both a compliant polyether molecular chain and a reactive epoxy group, the amine curing agent is added. Can react.
Polyurethane epoxy resin was prepared by bulk polymerization, which not only maintained the epoxy structure, but also introduced a flexible polyether side chain, which greatly improved the elongation of the slurry. Since the polyurethane epoxy resin does not contain active -NCO, furfural-acetone can be used as a reactive diluent, not only effectively reducing the viscosity of the pulp, but also forming the fluorenone resin under certain conditions. According to reports, it can also be used as a curing agent ketimine made of aliphatic amines and aromatic amines, the curing agent used is less than the corresponding epoxy slurry, so the cost is not high. Of course, the early strength of the cured product is relatively low. To cure completely and obtain higher strength, curing at room temperature is required for a certain period of time. However, this will not affect the application of concrete and bedrock fissures.