Polyurethane surfactants provide excellent protection for high-speed train components: a choice of equal importance to speed and safety

Introduction

As an important part of modern transportation, high-speed trains are crucial to their safety, reliability and durability. As the speed of trains continues to increase, the environmental conditions faced by train components are becoming increasingly stringent, including high-speed airflow, temperature changes, mechanical vibration and chemical corrosion. Therefore, how to effectively protect high-speed train components and extend their service life has become one of the hot spots in current research. As a highly efficient functional material, polyurethane surfactant has gradually become an ideal choice for the protection of high-speed train parts due to its excellent performance.

This article will discuss its application in the protection of high-speed train components in detail from the aspects of the characteristics, application principles, product parameters, and domestic and foreign research progress of polyurethane surfactants, and demonstrate its outstanding performance in practical applications through tables and data analysis.

1. Characteristics of polyurethane surfactants

1.1 Chemical structure and properties

Polyurethane surfactant is a polymer compound produced by chemical reactions of polyols, isocyanates and small molecule chain extenders. Its molecular structure contains both hard segments (isocyanate part) and soft segments (polyol part). This unique structure makes it have the following characteristics:

• High mechanical strength: Hard segments provide rigidity, and soft segments provide elasticity, making the material both toughness and strength.
• Excellent chemical resistance: able to resist the erosion of a variety of chemical substances, including acids, alkalis, oils and solvents.
• Good adhesion: Ability to firmly adhere to metal, plastic and composite surfaces.
• Weather Resistance: It can maintain stable performance under high temperature, low temperature and ultraviolet irradiation.

1.2 Special functions of surfactants

Polyurethane surfactants not only have the properties of ordinary polyurethane, but also have the following advantages due to their surfactivity:

• Reduce surface tension: Can effectively wet the surface of the substrate and improve the uniformity and adhesion of the coating.
• Self-healing ability: Some polyurethane surfactants have a micro-phase separation structure that can achieve self-healing after mechanical damage.
• Anti-bacterial and mildew: By introducing functional groups, the material is imparted with antibacterial and mildew-proof properties.

2. Polyurethane surfactants areApplication principle in the protection of high-speed train parts

2.1 Challenges of high-speed train components

High-speed train components (such as body, bogies, wheelsets, braking systems, etc.) face the following challenges during operation:

• High-speed airflow impact: When the train is running, the surface of the vehicle body is washed by the high-speed airflow, which can easily lead to coating peeling and material fatigue.
• Temperature Change: The train runs under different climatic conditions, and the temperature of the component surface changes violently, which may cause the material to expand or shrink.
• Mechanical Vibration: Vibration generated when the train runs at high speed will accelerate wear and fatigue of components.
• Chemical corrosion: Environmental factors such as rain, snow, salt spray, etc. can cause corrosion to metal parts.

2.2 Protection mechanism of polyurethane surfactants

Polyurethane surfactants provide protection for high-speed train components through the following mechanisms:

1. Form a dense protective layer: Polyurethane surfactant can form a dense protective film on the surface of the component, effectively isolating the external environment into the substrate.
2. Absorbing mechanical energy: Its high elasticity and toughness can absorb vibration energy during train operation and reduce mechanical fatigue of components.
3. Temperature resistance: It can maintain stable physical and chemical properties under high and low temperature conditions.
4. Self-repair function: Some polyurethane surfactants have the ability to self-repair microcracks and can extend the service life of the coating.

III. Product parameters of polyurethane surfactants

The following are several typical polyurethane surfactant product parameters:

IV. Progress in domestic and foreign research

4.1 Current status of domestic research

In recent years, significant progress has been made in the research and application of polyurethane surfactants in China. For example:

• Tsinghua University has developed a polyurethane surfactant with self-healing function, which can effectively extend the service life of high-speed train coatings.
• Institute of Chemistry, Chinese Academy of Sciences studied the properties of polyurethane surfactants in high temperature environments and found that they can remain stable under 120?.
• CRRC has applied polyurethane surfactant to the body coating of high-speed trains, which has significantly improved the weather resistance and corrosion resistance of the body.

4.2 Current status of foreign research

Foreign research in the field of polyurethane surfactants is also in-depth:

• BASF, Germany has developed a highly weather-resistant polyurethane surfactant, which is widely used in European high-speed trains.
• DuPont, USA, studied the antibacterial properties of polyurethane surfactants, providing new ideas for the hygiene protection of internal parts of the train.
• Japan Toray has developed a low viscosity polyurethane surfactant suitable for the coating of complex-shaped parts.