Successful development of the hottest polyurethane

Successful development of polyurethane epoxy slurry

the inaugural meeting of polyurethane epoxy slurry civil aircraft material industry development alliance and the first member congress were held in Shanghai Academy of aircraft Sciences

on June 28, 2004

polyurethane epoxy slurry, which integrates the advantages of epoxy slurry and polyurethane slurry, was 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. This product has high compressive strength Bonding strength, tensile strength and certain elongation are suitable for crack grouting of concrete and bedrock

concrete (or reinforced concrete) is a heterogeneous brittle material, which is prone to cracks. Grouting is the most important method for internal reinforcement of concrete cracks. The purpose of grouting is to restore the integrity of the structure and the design application state. Polyurethane slurry (refers to water-insoluble) is easy to diffuse, has good pouring performance, has strong adhesion with concrete and various materials, and the consolidated body has good elasticity and high impact strength; However, the viscosity of prepolymer is large, so it is difficult to find active diluent. At the same time, it is easy to foam. The compression and tensile properties of the consolidated body are also inferior to those of epoxy grout. It is more used as impermeable and plugging grouting materials

epoxy mortar has high bonding strength, good stability and uncomplicated construction, but epoxy resin itself is a rigid material with high inherent net brittleness, high elastic modulus and low elongation. When the bonding surface bears stress, it will soon cause crack propagation and crack adhesive layer. A new grouting material, polyurethane epoxy grout, is made by grafting polyurethane onto epoxy resin molecules, which not only overcomes the shortcomings of inactive diluent and low strength of polyurethane grout, but also overcomes the shortcomings of further improving the manufacturing technology level and overall strength of epoxy grout, which is brittle

it is reported that the main raw materials of polyurethane epoxy paste currently include epoxy resin, polyether polyol, polyisocyanate, grease JG158 (2) 004 "rubber powder polystyrene particle external wall external insulation system", aliphatic polyamines, aromatic polyamines, active diluents, catalysts, reaction rate regulators, etc. The synthesis process is to graft polyurethane onto epoxy resin molecules to obtain polyurethane epoxy resin. Because polyurethane epoxy resin molecules contain both flexible polyether molecular chains and active epoxy groups, amine curing agents can be added to react

polyurethane epoxy resin is prepared by bulk synchronous polymerization. The resin not only maintains the epoxy structure, but also introduces flexible polyether side chain, which greatly improves the elongation of the pulp. Because polyurethane epoxy resin does not contain active NCO, furfural acetone can be used as active diluent, which not only effectively reduces the viscosity of pulp, but also forms furfural ketone resin under certain conditions. According to the introduction, it can also use ketimine made of aliphatic amine and aromatic amine as the curing agent. 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 high strength, it takes a certain time to cure at room temperature. However, this will not affect the application of concrete and bedrock crack treatment