Microporous polyurethane elastomer compound with excellent dynamic performance and preparation method thereof

Abstract

The invention belongs to the field of polyurethane elastomer synthesis, and particularly relates to a preparation method of a microporous polyurethane elastomer compound with excellent dynamic performance. The compound is characterized in that the compound consists of a polyol mixture component and a modified isocyanate component. The preparation method has the advantages as follows: (1) a quasi-prepolymer method is adopted to process microporous polyurethane elastomer material, the two components has similar viscosity and similar mass mixing ratios, the material mixing temperature is low, the materials are easy to mix evenly, the process control condition is simple, and the operation is easy; and (2) the microporous polyurethane elastomer material prepared by using the compound disclosed by the invention has the advantages that a ratio of dynamic stiffness to static stiffness is smaller than or equal to 1.35, the impact elasticity is larger than or equal to 75 percent, the appearance is not damaged after 3,000,000 times of fatigue tests and the dimensional change rate is smaller than or equal to 20 percent, so that the compound can be used for preparing high-performance products such as damping cushion blocks of high-speed railways and damping elements of automobiles.

Description

technical field [0001] The invention belongs to the field of polyurethane elastomer synthesis, in particular to the preparation of a microporous polyurethane elastomer composition with excellent dynamic performance. Background technique [0002] Microcellular polyurethane elastomer is a new type of material between elastomers and foam materials. Its cell diameter is generally 0.1-10 μm, the cells are fine and uniform, and its density is lower than that of solid elastomer materials, while its mechanical properties are more obvious. It is higher than common foam materials, so microcellular polyurethane elastomer has the dual advantages of light weight and comfort of foam materials, high strength and good mechanical properties of elastomer materials, and has the characteristics of good cushioning performance and excellent fatigue resistance. It is an elastic material with excellent comprehensive properties, and has broad application potential in some special fields, such as the...

AI Technical Summary

Problems solved by technology

Traditional common polyethers are mostly obtained by ring-opening polymerization of propylene oxide and ethylene oxide. The molecular structure contains a large number of side methyl groups. Although the molecular structure is relatively regular, when subjected to alternating external forces, the molecular chain The movement is affected by the steric resistance of the side base, and the deformation will lag behind the stress change, the energy loss will increase, and the dynamic and static stiffness ratio will also increase significantly. Therefore, it is difficult for its dynamic and static stiffness to reach the dynamic and static stiffness of the current high-speed railway pad Ratio ≤ 1.35 requirements

[0004] Patent CN100506871C reported a preparation method of NDI-based polyurethane microporous elastomer. As we all know, the polyurethane material prepared by NDI has excellent dynamic performance, small damping property and high resilience, and is especially suitable for dynamic load and heat resistance occasions. , but this material has a high melting point, the process of preparing polyurethane materials is complicated, and the storage stability is very poor. The prepared prepolymer has only a few hours of storage stability.

Patent CN101469054B reported a preparation method of PPDI-based polyurethane microcellular elastomer, which has good dynamic performance and good storage stability of prepolymer, but PPDI has a high melting point and complicated processing technology; CN101380442B reported a TODI-based The preparation method of polyurethane microcellular elastomer has good processing performance, and the prepared polyurethane microcellular elastomer material has excellent heat resistance, wear resistance and dynamic fatigue performance

However, the isocyanates used in the above patents are all special isocyanates, and the cost of raw materials is relatively high; Partial viscosity is large, the viscosity difference between the two components is large, the mixing temperature of the materials is high, the mass ratio difference between the two components is large, it is difficult to mix evenly, and the product quality is not easy to control stably

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