Discussion on the importance of polyurethane TPE anti-yellowing agent in ship manufacturing

A discussion on the importance of polyurethane TPE anti-yellowing agent in ship manufacturing

1. Introduction: Start with "yellow"

When it comes to "yellow", you may think of the golden leaves in autumn, or the warm tones of sunshine on the sea. But if it is in the field of ship manufacturing, "yellow" may not be so romantic. What we are going to talk about today is a special chemical - polyurethane thermoplastic elastomer (TPE) anti-yellowing agent. It is like an unknown "guardian", which specializes in preventing the material from yellowing due to light or aging, thus ensuring the long-lasting and bright appearance of the ship.

Ship manufacturing is a complex engineering involving a variety of materials and processes. However, no matter how exquisite the design or how advanced the technology is, if the material on the surface of the hull gradually turns yellow during use, it will not only reduce the aesthetics, but may also affect the material performance and even shorten the service life of the ship. Therefore, how to effectively suppress the yellowing of materials has become an issue that cannot be ignored in the shipbuilding industry.

Polyurethane TPE is a high-performance material and is widely used in ship manufacturing, but it is susceptible to factors such as ultraviolet rays and oxygen, resulting in yellowing problems. To solve this problem, anti-yellowing agents emerged. This additive can not only delay the aging process of the material, but also maintain its original color and luster. It can be called a "beautician" in ship manufacturing.

This article will start from the basic principles of polyurethane TPE anti-yellowing agent, deeply explore its important role in ship manufacturing, and analyze its application effect based on actual cases. At the same time, we will also reveal new progress and technical trends in this field by comparing relevant domestic and foreign research. I hope this article can provide readers with a comprehensive and easy-to-understand guide to give everyone a deeper understanding of this seemingly professional but closely related to life.

2. Basic concepts of polyurethane TPE anti-yellowing agent

(I) What is polyurethane TPE?

Polyurethane thermoplastic elastomer (TPE) is a polymer material that combines rubber elasticity and plastic processability. Simply put, it has the characteristics of soft and wear-resistant rubber, and the advantages of easy molding of plastics, so it is widely used in automobiles, electronics, medical care, and ship manufacturing.

The main components of polyurethane TPE include hard segments (such as diisocyanate) and soft segments (such as polyether or polyester polyols). The hard segments give the material higher strength and heat resistance, while the soft segments provide flexibility and resilience. However, since polyurethane molecules contain unsaturated bonds and aromatic groups, these structures are prone to oxidation and degradation when exposed to ultraviolet light, high temperature or humid environment for a long time, which in turn causes yellowing.

(II) Mechanism of action of anti-yellowing agent

Anti-yellowing agents are a class of chemicals that can inhibit or slow down the yellowing of materials.Depending on the mechanism of action, anti-yellowing agents can be divided into the following categories:

Ultraviolet absorber
This type of anti-yellowing agent can absorb UV energy and convert it into heat energy to release it, thereby avoiding the damage of UV light to material molecules. Common UV absorbers include benzotriazoles, salicylates and benzophenone compounds.
Free Radical Capture
Free radicals are one of the culprits that cause material aging. The free radical trapping agent can terminate the chain reaction by reacting with the free radical, thereby protecting the material from further damage.
Antioxidants
Antioxidants mainly delay the aging rate of materials by interrupting the chain transfer process of the oxidation reaction. They are usually classified into primary antioxidants (such as phenolic compounds) and secondary antioxidants (such as phosphites).
Metal ion passivator
Certain metal ions (such as iron, copper, etc.) will catalyze the oxidation reaction of materials and accelerate the occurrence of yellowing. Metal ion passivators can stabilize these ions through chelation, reducing their adverse effects on the material.

(III) Product parameters list

To better understand the properties of polyurethane TPE anti-yellowing agents, the following lists key parameters for some common products:

parameter name	Unit	Reference value range	Remarks
Appearance	——	White powder/transparent liquid	Influence the addition method and dispersion
Melting point	℃	50-120	Determines the processing temperature
Density	g/cm³	1.0-1.3	Related to the calculation of usage
Add ratio	%	0.1-2.0	Adjust to demand
Photostability	——	>80%	MeasurementRetention rate after UV irradiation
Compatibility	——	Excellent	Match to the substrate

III. Application of polyurethane TPE anti-yellowing agent in ship manufacturing

(I) Special environmental challenges in ship manufacturing

Ships sail in marine environments all year round and face a series of unique challenges:

Strong UV radiation: Sea water reflects sunlight, causing the surface of the hull to withstand higher UV intensity than on land.
High humidity and salt spray erosion: The ocean air contains a lot of salt, which can corrode the material.
Frequent temperature difference changes: exposure to the sun during the day and cooling at night may cause stress cracks inside the material.

With these factors combined, if effective protective measures are not taken, polyurethane TPE products are prone to yellowing, cracking and other problems, which seriously affects the appearance and function of the ship.

(II) Specific application of anti-yellowing agent

In ship manufacturing, polyurethane TPE anti-yellowing agent is mainly used in the following aspects:

Hull Coating
The outer coating of the ship needs to have good weather resistance and decorative properties. By adding anti-yellowing agent, the color retention ability of the coating can be significantly improved, so that it remains bright after long-term use.
Seals and gaskets
The seals and gaskets on ships are mostly made of polyurethane TPE to prevent water leakage and sound insulation. This type of component is prone to yellowing or even failing when exposed to water vapor and sunlight for a long time. The addition of anti-yellowing agents helps to extend their service life.
Interior Materials
The floors, seats and other decorative materials in the cabin also need to be considered for yellowing resistance. Especially on luxury cruise ships, passengers have higher requirements for the indoor environment, so it is particularly important to choose high-quality anti-yellowing agents.

(III) Actual case analysis

Taking an internationally renowned yacht manufacturer as an example, the company has introduced a new composite anti-yellowing agent in the outer coating of its new yachts. After two years of actual testing, the results showed that the yellow index of the new coating was reduced by about 60% compared to products without the anti-yellowing agent, and the surface gloss was maintained at the initial level.More than 90% of the This not only improves the overall appearance of the yacht, but also reduces maintenance costs.

IV. Comparison of current domestic and foreign research status and technology

(I) Foreign research trends

In recent years, European and American countries have made significant progress in the field of polyurethane TPE anti-yellowing agents. For example, BASF, Germany has developed an efficient ultraviolet absorber based on nanotechnology, with particle sizes of only a few dozen nanometers, which can provide excellent protection without affecting the transparency of the material. In addition, DuPont, the United States, has launched a multifunctional anti-yellowing agent that integrates various functions such as ultraviolet absorption, free radical capture and antioxidant, and is suitable for marine applications under complex operating conditions.

(II) Domestic development

my country's research on polyurethane TPE anti-yellowing agents started late, but has made rapid progress in recent years. The Institute of Polymer Sciences of Zhejiang University has successfully synthesized a new benzotriazole ultraviolet absorber, whose absorption efficiency is nearly 30% higher than that of traditional products. At the same time, the Institute of Chemistry, Chinese Academy of Sciences is also exploring the possibility of using natural plant extracts as green anti-yellowing agents, striving to achieve dual breakthroughs in environmental protection and performance.

(III) Technology comparison

The following is a technical comparison of some representative anti-yellowing agents at home and abroad:

Technical Indicators	Representative products from abroad	Domestic Representative Products	Difference Points
Absorption wavelength range	290-400 nm	300-380 nm	Wide coverage abroad
Dispersion uniformity	very good	Better	Foreign technologies are more mature
Cost	Higher	Lower	There is more price advantage in China
Environmental	Complied with EU standards	Improving	The domestic connection between laws and regulations is still needed

5. Future development trends and prospects

With the rapid development of the global shipping industry, ship manufacturing has higher and higher requirements for material performance. Against this background, the research and development direction of polyurethane TPE anti-yellowing agent will also be more diversified and refined. Specifically, the following trends are worth paying attention to:

Intelligent upgrade
With the help of IoT technology and sensor monitoring, future anti-yellowing agents are expected to achieve adaptive adjustment functions and automatically optimize the protection effect according to environmental conditions.
Green and environmentally friendly
Against the backdrop of the "dual carbon" goal, the development of anti-yellowing agents prepared by renewable resources will become an important topic.
Multi-function integration
Combining anti-yellowing function with other properties (such as fire resistance, antibacterial, etc.) to form an integrated solution.

In short, polyurethane TPE anti-yellowing agent is not only one of the key technologies in ship manufacturing, but also a powerful tool to promote the sustainable development of the industry. I believe that with the continuous advancement of science and technology, this field will usher in a more brilliant tomorrow!

6. Conclusion: Let the ship stay young forever

If the ship is a building floating on the sea, then polyurethane TPE anti-yellowing agent is its "skin care product". It is precisely with these tiny chemical molecules that our ships can still shine in the wind and waves. I hope that the content of this article will give you a deeper understanding of this field, and at the same time, we also look forward to more innovative achievements emerging to provide more possibilities for mankind to explore the ocean!