A kind of high cold-resistant polyurethane shock-absorbing pad and preparation method thereof

Abstract

The invention provides a high cold-resistant polyurethane shock-absorbing pad and a preparation method thereof. The polyurethane shock absorber is formed by mixing and crosslinking components A and B; wherein, component A is a polyol composition, including the following raw materials: caprolactone-modified polyether polyol, polyether polyol, terminal Hydroxy polybutadiene, terminal primary hydroxyl siloxane, chain extender, catalyst, foam stabilizer, foaming agent; B component is NCO blocked isocyanate prepolymer, including the following raw materials: caprolactone modified polyether Polyols, 4,4-diphenylmethane diisocyanate, side reaction inhibitors. The high cold-resistant polyurethane shock-absorbing pad prepared by the invention has good shock-absorbing performance and excellent dynamic fatigue resistance, and the low-temperature performance is significantly improved, and can be used in the construction fields of Moscow-Kazan high-speed railway and railways in cold regions such as Northern Europe and Siberia. And the field of automobile shock absorption in extremely cold regions.

Description

technical field [0001] The invention belongs to the field of polyurethane material synthesis, and in particular relates to a high cold-resistant polyurethane shock-absorbing pad and a preparation method thereof. Background technique [0002] Polyurethane elastic materials have been widely used in various fields including the shock absorption field of high-speed railways because of their good mechanical properties, excellent weather resistance, chemical medium resistance and aging resistance. With the rapid development of my country's railway construction and the continuous improvement of train operating speed, the safety of high-speed train operation has attracted increasing attention, and higher and higher requirements have been put forward for the comprehensive performance of polyurethane shock absorbing pads. [0003] Chinese patent CN101942786A discloses a rail backing plate and its preparation method. This technical solution is compounded with commonly used polyester / po...

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Problems solved by technology

[0003] Chinese patent CN101942786A discloses a rail backing plate and its preparation method. This technical solution is compounded with commonly used polyester / polyether polyols and added with a small molecule crosslinking agent. The resulting product has high rigidity and poor low temperature performance. It cannot be applied to the field of high-speed rail shock absorption in low-temperature regions of ≤ -40°C, and in the preparation process, the water content needs to be adjusted many times, the process is complicated, and it is not conducive to actual production

Chinese patent CN104672423A discloses a method for preparing polyurethane microporous elastomers for high-speed railways. In this method, polyester polyols / butylated hydroxyl polyols are used to compound and prepare composite materials, and prepolymers are prepared by commonly used polyester / MDI reactions for 2 hours. Mix the prepared combination material and prepolymer into the aluminum mold, take out the mold after 10 minutes, and mature at 100°C for 3 hours to obtain an elastic backing plate; the backing plate prepared by this method has poor fatigue resistance and uncertain low temperature performance. The synthesis efficiency of the body is low, and the prepared backing plate needs to be cured at high temperature, and the energy consumption is high

Chinese patent CN104592744A discloses a shock-absorbing pad for high-speed railway and its manufacturing method. Group B composed of isocyanate is placed in working tanks A and B of the pouring machine respectively, mixed according to a certain proportion and poured into a mold at 45°C to 55°C, demolded after 30 minutes of heat preservation, and post-cured at 75°C to 85°C for 10 hours to 14h; Although the damping pad obtained by this technical scheme can be used in the environment of -40°C, the material B used is diphenylmethane diisocyanate, which has a high NCO content, and the comprehensive performance of the high-speed iron damping pad prepared by one-step method is poor. The reaction speed is violent, the appearance of the product is not easy to control, post-curing requires a high temperature environment, and the energy consumption is high

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