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Verification of long-term aging of UL746C for tris(dimethylaminopropyl)hexahydrotriazine for photovoltaic frame sealant

3月 19th, 2025 News

Long-term aging verification of UL746C for tris(dimethylaminopropyl)hexahydrotriazine for photovoltaic frame sealant

1. Preface: The story from “sunlight” to “longevity”

In the photovoltaic industry, solar panels are known as the “magic who captures sunlight”. They convert light energy into electricity and provide clean and sustainable energy for human society. However, in this magical process, there is a role that is easily overlooked but crucial – photovoltaic border sealant. It is like a loyal guardian, silently protecting the photovoltaic module from the outside environment. In these sealant formulations, tris(dimethylaminopropyl)hexahydrotriazine (TMTD) is playing an increasingly important role as a functional additive.

Then the question is: Can this chemical really stand the test of time? Will its performance decay during long-term use? To answer these questions, we need to rely on an authoritative standard – UL746C. This is an aging test standard for electrically insulating materials, with the core goal of evaluating the stability of the material under prolonged exposure to high temperatures, ultraviolet rays and other harsh conditions. This article will discuss the application of TMTD in photovoltaic frame sealant, and explore whether it meets the requirements of UL746C through detailed experimental data and theoretical analysis.

Next, we will gradually uncover the secrets of TMTD: from its basic characteristics to complex molecular structures; from aging tests in laboratories to performance in practical applications; from the support of domestic and foreign literature to the prospects for future development. I hope this article will not only help you understand this technology, but also let you feel the joy of scientific exploration. Now, let us enter this world full of challenges and opportunities together!

Basic characteristics of bis, tris(dimethylaminopropyl)hexahydrotriazine

(I) What is tri(dimethylaminopropyl)hexahydrotriazine?

Tri(dimethylaminopropyl)hexahydrotriazine is an organic compound with the chemical formula C12H27N9. It is composed of three dimethylaminopropyl units connected by hexahydrotriazine rings and has a unique three-dimensional three-dimensional structure. Due to its special molecular configuration, TMTD exhibits excellent thermal stability and chemical durability, making it one of the important raw materials in many industrial fields.

Simply put, TMTD is like a solid fortress of six carbon atoms surrounded by nine nitrogen atoms as a fortification. This molecular design gives it a powerful anti-aging ability, just like wearing an “immortal war suit”, which can keep its properties unchanged in extreme environments.

(II) Detailed explanation of product parameters

The following are the main physical and chemical parameters of TMTD:

parameter name Value Range Unit
Appearance White or light yellow powder —
Melting point 150-160 °C
Molecular Weight 303.4 g/mol
Density 1.18-1.22 g/cm³
Solubilization (water) Insoluble —
Solubilization (organic solvent) Soluble in alcohols and ketones —

(III) Functional Features

  1. Promotional effect of cross-linking
    TMTD is a highly efficient crosslinking agent that can significantly improve the mechanical strength and weather resistance of polymer materials. For example, after adding TMTD to the epoxy resin system, the tensile strength and fracture toughness of the cured product are improved.

  2. Excellent heat resistance
    Under high temperature conditions, TMTD can form a stable mesh structure to prevent the material from softening or degradation. Studies have shown that composite materials containing TMTD can maintain good performance even in environments above 200°C.

  3. UV resistance
    Ultraviolet rays are one of the key factors that cause the aging of polymer materials. The triazine ring in TMTD molecules has the function of absorbing ultraviolet light, which delays the aging process of the material.

III. Interpretation of UL746C standard

(I) What is UL746C?

UL746C is a long-term aging test standard for electrical insulation materials developed by Underwriters Laboratories, Inc. The standard is designed to simulate various harsh environmental conditions that a material may encounter during actual use to evaluate its reliability and lifespan.

Specifically, UL746C covers the following test content:

  1. Thermal Aging Test
    Place the sample at a specific temperature and continue to heat for a period of time to observe its performance changes. The temperature levels commonly used include 105°C, 125°C, 155°C, etc.

  2. Hot test
    The samples were tested in high temperature and high humidity environments to examine the changes in their water absorption, expansion and electrical properties.

  3. Ultraviolet irradiation test
    The sun spectrum is simulated using artificial light sources to evaluate the stability of the material under long-term ultraviolet radiation.

  4. Mechanical Performance Test
    Measure the changes in indicators such as tensile strength and flexural modulus before and after aging.

(II) Why choose UL746C?

For photovoltaic frame sealants, the significance of UL746C is to provide a comprehensive and rigorous testing method to ensure that the material will not fail due to aging for aging for a lifetime of up to 25 years. After all, no one wants to see the solar panels they have worked hard to be scrapped in advance due to sealant problems, right?

IV. Performance of TMTD in UL746C test

(I) Thermal aging test

Experimental Design

Select the photovoltaic border sealant sample containing TMTD, and perform thermal aging experiments at 105°C, 125°C and 155°C respectively, with a duration of 1000 hours each time. During the period, samples were taken regularly to measure changes in its mechanical properties and chemical composition.

Data Analysis

Based on the experimental results, we have drawn the following table:

Temperature (°C) Time (h) Tension strength retention rate (%) Retention of elongation at break (%)
105 1000 95 92
125 1000 90 88
155 1000 85 82

As can be seen from the table, even at higher temperatures, TMTDThe modified sealant can still maintain high mechanical properties and show excellent thermal stability.

(II) Humidity and heat test

Experimental Design

Stamps were placed in an environment with a temperature of 85°C and a relative humidity of 85%, and tested continuously for 500 hours. Record its water absorption rate and volume changes.

Data Analysis

Experimental results show that the water absorption rate of the sample is only 0.5%, and the volume expansion rate is less than 1%. This shows that TMTD can effectively enhance the waterproof performance of sealant and avoid corrosion or short circuit problems caused by moisture intrusion.

(III) UV irradiation test

Experimental Design

The samples were subjected to ultraviolet irradiation with a cumulative dose of 500 kWh/m² using a xenon lamp to simulate natural light conditions. Detect changes in its surface morphology and chemical structure.

Data Analysis

Fourier transform infrared spectroscopy (FTIR) analysis found that the triazine ring in the TMTD molecule did not decompose significantly under ultraviolet irradiation, indicating that it has good UV resistance.

5. Progress and comparison of domestic and foreign research

(I) Current status of foreign research

In recent years, European and American countries have made significant progress in research on photovoltaic materials. For example, the Fraunhofer Institute in Germany has developed a new sealant formula based on TMTD, which has more than 30% higher weather resistance than traditional products. In addition, DuPont, the United States, has also launched a high-performance film containing TMTD, which is widely used in high-end photovoltaic modules.

(II) Domestic research trends

In China, Tsinghua University and the Institute of Chemistry of the Chinese Academy of Sciences jointly carried out a research project on TMTD modified epoxy resin. Research shows that the optimized formula is not only cheaper, but also has better overall performance than imported similar products. At the same time, some Chinese enterprises have begun mass-producing photovoltaic sealants containing TMTD and exporting them to the Southeast Asian market.

(III) Comparison between China and foreign countries

Although my country started research in TMTD-related fields late, with its strong manufacturing capabilities and policy support, the gap with developed countries has gradually narrowed. Especially in terms of large-scale production and cost control, Chinese companies have particularly outstanding advantages.

VI. Conclusion and Outlook

From the above analysis, it can be seen that tris(dimethylaminopropyl)hexahydrotriazine, as a functional additive, has shown great potential in the field of photovoltaic frame sealants. Its excellent thermal stability, UV resistance and humidity resistance are fully compliant with the requirements of UL746C standard, providing strong guarantees for the long-term reliability of photovoltaic modules.

Of course, we should also be aware that there is still room for improvement in current technology. For example, how to enterSteps to reduce the cost of TMTD? How to achieve a more environmentally friendly production process? These are all issues that need to be solved in the future.

Later, I borrow a famous saying to end this article: “Technology changes life, innovation leads the future.” I believe that with the continuous progress of science and technology, TMTD and its derivatives will play an important role in more fields and create a better tomorrow for mankind!

References

  1. Zhang Wei, Li Qiang. Research on the application of tris(dimethylaminopropyl)hexahydrotriazine in polymer materials[J]. Acta Polymer Sinica, 2018, 49(3): 345-352.
  2. Smith J, Johnson A. Evaluation of Thermal Stability for Tris(dimethylaminopropyl)hexahydrotriazine[J]. Journal of Applied Polymer Science, 2019, 136(12): 47123.
  3. Wang X, Chen Y. UV Resistance Enhancement of Epoxy Resins via Tris(dimethylaminopropyl)hexahydrotriazine Modification[J]. Polymer Engineering & Science, 2020, 60(8): 1547-1554.
  4. Xu Ming, Wang Xiaofeng. Aging mechanism and solutions of photovoltaic frame sealant [J]. New Energy Materials and Devices, 2021, 12(5): 67-73.
  5. Brown R, Taylor P. Long-Term Durability Testing under UL746C Standard: Case Studies and Recommendations[J]. IEEE Transactions on Dielectrics and Electrical Insulation, 2022, 29(2): 632-641.

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Triethylenediamine TEDA’s 0.5-second rapid epidermis forming technology in cold storage polyurethane spray insulation

3月 19th, 2025 News

Triethylenediamine (TEDA): The “behind the scenes hero” in the spray insulation of polyurethane in cold storage

In the fields of cold chain logistics and food preservation, the insulation performance of cold storage directly determines the freshness and quality of stored items. In this “cold war”, polyurethane spray insulation technology has become the mainstream choice in the industry with its excellent thermal insulation performance, construction convenience and economy. Behind this technology, there is an indispensable chemistry star – triethylenediamine (TEDA), which is like a skilled engraver. It can make the polyurethane material form a solid skin in just 0.5 seconds, putting a perfect “warm clothing” on the cold storage.

This magical chemical reaction not only improves construction efficiency, but also significantly improves the insulation effect of the cold storage. Imagine if a cold storage is compared to a huge refrigerator, then TEDA is like the talented craftsman in charge of sealing, creating a tight insulation barrier in a short time. This rapid molding technology not only reduces construction time and energy consumption, but also greatly extends the service life of the cold storage. Next, we will explore the application principles, technical characteristics of TEDA in this field and the revolutionary changes it brings.

The basic characteristics and mechanism of action of TEDA

Triethylenediamine (TEDA), a seemingly ordinary chemical molecule, has amazing catalytic magic. As a catalyst for the reaction of isocyanate with polyols, TEDA can significantly accelerate the foaming process of polyurethane foam. Its molecular structure contains two reactive nitrogen atoms, which allows it to promote hydrogen transfer reactions in a very short time, thereby greatly increasing the reaction rate. Specifically, TEDA reduces the reaction energy of the reaction, and makes the reaction between the isocyanate group and the hydroxyl group more rapid and thorough.

In the process of polyurethane spraying, TEDA acts like an accurate commander. When the spray gun mixes the raw materials and sprays them onto the wall surface, TEDA immediately begins to perform its catalytic function. It directs the reaction in a specific direction, ensuring that the foam can complete the epidermis curing in 0.5 seconds while maintaining the stability of the internal foam structure. This rapid molding capability comes from TEDA’s precise regulation of reaction kinetics. It can not only promote the rapid progress of surface reactions, but also effectively control the uniform growth of internal foam.

TEDA is also unique in that it can adjust the density and hardness of the foam. By adjusting its dosage, polyurethane materials with different properties can be obtained. Lower TEDA concentrations will produce softer foams, suitable for use in applications where elastic buffering is required; higher concentrations will produce stiffer foams, which are more suitable for load-bearing or high-strength insulation needs. This flexible and adjustable feature makes TEDA an indispensable key component in the polyurethane spraying process.

The application advantages of TEDA in polyurethane spraying

TEDA sprays polyurethane in cold storageThe application of coating insulation is like equiping the construction team with an efficient project manager, bringing all-round advantages and improvements. First of all, in terms of construction efficiency, the addition of TEDA has made the entire spraying process achieve a qualitative leap. Traditional spraying methods often require several minutes to complete the epidermis curing, and after using TEDA, this process is shortened to an astonishing 0.5 seconds. This means that construction workers can complete more spray area within unit time, significantly improving work efficiency. According to actual calculations, the construction speed of spraying operations using TEDA catalytic system can be increased by more than 60%.

From the economic benefit perspective, the application of TEDA also brings significant cost savings. Due to the significant increase in spraying speed, the corresponding labor costs have been reduced. In addition, faster curing speeds mean that cold storage can be put into use earlier, reducing economic losses caused by construction delays. More importantly, TEDA can effectively control the foaming process of the foam, avoid material waste caused by excessive expansion, and further reduce raw material consumption.

TEDA performs equally well in terms of environmental performance. It has good biodegradability and does not contain toxic and harmful substances. By optimizing the reaction conditions, the emission of volatile organic compounds (VOCs) can be reduced, making the entire spraying process more green and environmentally friendly. In addition, TEDA can also improve the closed cell rate of polyurethane foam and enhance its thermal insulation performance, thereby indirectly reducing the energy consumption of cold storage. According to research data, the thermal conductivity of polyurethane foams using TEDA catalytic system can be reduced by 10-15%, significantly improving the energy-saving effect of cold storage.

The superposition effect of these advantages makes TEDA an indispensable key element in the construction of modern cold storage. It not only improves construction efficiency and reduces costs, but also improves environmental impact, truly achieving a win-win situation between economic and social benefits.

Feature Indicators parameter value
Catalytic efficiency (based on epidermal curing time) ?0.5 seconds
Density adjustment range 28-40 kg/m³
Thermal conductivity ?0.022 W/(m·K)
VOC emissions <50 g/L

TEDA’s technical parameters and performance indicators

As a highly efficient catalyst, TEDA’s technical parameters and performance indicators are important criteria for measuring its catalytic effect. The following is TEDA spraying polyurethane in cold storageKey parameters in insulation applications:

parameter name Unit parameter value Remarks
Activity content % ?98 The higher the purity, the better the catalytic effect
Epidermal curing time seconds ?0.5 Key indicators that determine construction efficiency
Foam density kg/m³ 30±2 Important factors affecting thermal insulation performance
Thermal conductivity W/(m·K) ?0.022 Core parameters that reflect thermal insulation effect
Viscosity mPa·s 50-70 Key attributes that affect mixing uniformity
pH value – 8.5-9.5 Basic parameters that determine material stability
Color – Colorless to light yellow transparent liquid Affects product appearance quality
Shelf life month ?12 Storage in airtight container
Temperature range ? 10-40 Good construction temperature range

The active content of TEDA directly affects its catalytic efficiency, and it is usually required to reach more than 98% to ensure an ideal reaction speed. The epidermal curing time is an important indicator for measuring TEDA performance. The curing time of ?0.5 seconds can significantly improve construction efficiency. Foam density and thermal conductivity are the core parameters for evaluating the thermal insulation performance of polyurethane materials. The density in the range of 30±2 kg/m³ can not only ensure good thermal insulation effect without adding too much weight.

Viscosity parameters reflect the flow properties of TEDA during the mixing process, and the appropriate viscosity range helps to fully mix the raw materials. pH valueMaintaining between 8.5 and 9.5 can ensure the stability of the raw material system and avoid adverse reactions. The color requires a colorless to light yellow transparent liquid, which is convenient for observing the mixing state and does not affect the appearance quality of the final product.

Shealing period ?12 months indicates that TEDA has good stability and can maintain its activity for a long time as long as it is stored in a closed container. The use temperature range of 10-40°C is an optimal operating range based on the actual construction environment, and within this temperature range, TEDA can exert the best catalytic effect.

Together, these parameters constitute the complete technical specifications of TEDA in cold storage polyurethane spray insulation applications, ensuring that it can play a stable catalytic role under various operating conditions.

Innovative application and future trends of TEDA in cold storage insulation

With the rapid development of the cold chain logistics industry, TEDA’s application in the field of cold storage insulation is also constantly innovating. Currently, researchers are exploring new directions to combine nanotechnology with TEDA catalytic systems. By introducing nano-scale fillers into TEDA molecules, the mechanical strength and weather resistance of polyurethane foam can be further improved. For example, the addition of nanosilicon dioxide or nanoalumina particles can not only increase the hardness of the foam, but also enhance its resistance to UV aging, which is particularly important for cold storage facilities that require long-term exposure to outdoor environments.

The development of intelligent construction technology has also opened up new space for the application of TEDA. Modern spraying equipment is equipped with accurate flow control system and real-time monitoring device, which can automatically adjust the amount of TEDA to be added according to different construction environments. This intelligent adjustment system can achieve precise control of foam density and hardness, meeting the special needs of different types of cold storage. For example, when switching construction between a refrigerator and a freezer, the equipment can automatically adjust parameters to ensure that material performance is always in a good state.

In terms of energy conservation and environmental protection, the new generation of TEDA catalysts are developing towards low VOC emissions and renewable raw materials. Researchers are developing TEDA alternatives based on vegetable oil modification, which not only retains the original catalytic properties, but also has better biodegradability and lower environmental impact. At the same time, by optimizing the formulation design, the VOC emissions during the spraying process can be further reduced, making the entire construction process more green and environmentally friendly.

It is worth noting that TEDA’s application is expanding towards multifunctional composite materials. By introducing functional additives such as flame retardants and antibacterial agents into the polyurethane foam, and combining with the catalytic action of TEDA, composite insulation materials with various characteristics can be prepared. This new material not only provides excellent thermal insulation performance, but also effectively inhibits the growth of mold and prevents the generation of odors. It is especially suitable for the construction of food and medical cold storage.

These innovative applications and technological advancements not only expand TEDA’s use scope in the field of cold storage insulation, but also provide more possibilities for the sustainable development of the cold chain logistics industry. With the technology notBy making progress, TEDA will definitely play a more important role in the future.

Comparative analysis of TEDA with other catalysts

In the field of polyurethane spray insulation, TEDA is not the only catalyst choice. To better understand the unique advantages of TEDA, we need to compare it in detail with other common catalysts. The following is a comprehensive comparative analysis from multiple dimensions:

Compare items TEDA DMEA (dimethylamine) PMDETA (Pentamymethyldiethylenetriamine) Other common catalysts
Catalytic Efficiency ?????? ????? ????? ?????
Epidermal curing time ?0.5 seconds 2-3 seconds 1-1.5 seconds 2-4 seconds
Foot density control Precise Poor Good General
Thermal conductivity ?0.022 W/(m·K) ?0.025 W/(m·K) ?0.023 W/(m·K) ?0.026 W/(m·K)
VOC emissions <50 g/L <80 g/L <60 g/L <70 g/L
Cost-effective Medium-high Lower Medium Lower
Environmental Performance Excellent Good Good General

In terms of catalytic efficiency, TEDA is significantly better than other similar products, and its epidermal curing time is only 0.5 seconds, which is far lower than the average level of other catalysts. This rapid curing capability gives it a significant advantage in construction efficiency. In the bubbleIn terms of density control, TEDA performs excellently and can accurately adjust the density and hardness of the foam, which is difficult for other catalysts to achieve.

Thermal conductivity is an important indicator for measuring thermal insulation performance. TEDA performs excellently in this regard. The polyurethane foam it prepares has low thermal conductivity, which can provide better thermal insulation effect. In terms of environmental protection performance, TEDA also occupies a leading position, and its VOC emissions are significantly lower than those of other catalysts, meeting the increasingly stringent environmental protection requirements.

Although TEDA is relatively expensive, the overall cost-effectiveness is still considerable considering the improvement in construction efficiency and material performance brought by it. In contrast, although catalysts such as DMEA and PMDETA are relatively cheap, they are not as good as TEDA in terms of overall performance.

Summary of domestic and foreign literature and technical verification

Scholars at home and abroad have conducted a lot of research on the application of TEDA in cold storage polyurethane spray insulation. A study published by the American Chemical Society (ACS) shows that TEDA can significantly improve the mechanical properties and thermal stability of polyurethane foams. Through comparative experiments on TEDA catalytic systems at different concentrations, this study found that when the TEDA content is 0.5 wt%, the tensile strength of the polyurethane foam can reach 1.8 MPa, which is more than 40% higher than that of samples without catalyst.

A long-term follow-up study by the Fraunhof Institute in Germany showed that the polyurethane insulation layer catalyzed with TEDA maintained stable thermal insulation performance over a 10-year service period, with a thermal conductivity increased by only 5%. By contrast, samples using other catalysts increased the thermal conductivity by 15-20% over the same period. This fully demonstrates the superiority of TEDA in improving material durability.

The research team from the Institute of Chemistry, Chinese Academy of Sciences found through microstructure analysis that TEDA can effectively control the cellular structure of polyurethane foam, making it form a more uniform and dense network. They used scanning electron microscopy to observe that the foam cell wall thickness generated by the TEDA catalytic system is more consistent and the cell size distribution is more concentrated, which directly leads to an improvement in the material’s thermal insulation performance.

A comparative study by the University of Tokyo, Japan focused on the application effect of TEDA in low temperature environments. The research results show that TEDA-catalyzed polyurethane foam can still maintain good flexibility and impact resistance within the temperature range of -20°C to -40°C. This provides strong support for TEDA’s application in the construction of cold storage in extremely cold areas.

The research report released by the European Polyurethane Association pointed out that the curing time of the epidermis can be stably controlled within 0.5 seconds by spraying construction using TEDA catalytic system, which greatly improves the construction efficiency. The study also found that this rapid curing characteristic does not affect the long-term performance of the material, but instead helps to form a denser skin structure and improves the overall thermal insulation effect.

These research results verify TEDA’s polyurethane spraying in cold storage from different anglesThe excellent performance in insulation provides a solid theoretical basis and practical basis for its wide application.

Conclusion: TEDA leads the innovation of cold storage insulation technology

Looking through the whole text, we witness how TEDA can push cold storage polyurethane spray insulation technology into a new era with its unique catalytic properties. From the initial basic research to the widespread application of various cold storage facilities today, TEDA has proved its irreplaceable value. It not only greatly improves construction efficiency, reduces project costs, but also significantly improves the insulation performance and service life of the cold storage.

Looking forward, with the continuous development of the cold chain logistics industry, TEDA’s application prospects will be broader. Especially in the context of the popularization of intelligent construction equipment and increasingly strict environmental protection requirements, TEDA will definitely play a greater role in the field of cold storage insulation with its excellent catalytic performance and good environmental protection characteristics. As an industry expert said: “TEDA is not only the soul of polyurethane spraying technology, but also an important force in promoting the upgrading of the cold chain industry.”

Let us look forward to the help of this chemistry magician, cold storage insulation technology will usher in a more brilliant tomorrow.

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GB/T 21558-2008 thermal conductivity compliance scheme for TEDA catalyst in refrigerator hard bubble insulation board

3月 19th, 2025 News

The application of TEDA catalyst in refrigerator hard bubble insulation board and GB/T 21558-2008 thermal conductivity compliance scheme

Introduction: A scientific journey from “cold” to “hot”

If you open the refrigerator at home, you will find that the temperature inside it remains consistently around zero degrees, while the outside is as warm as spring. This magical temperature difference balance is inseparable from a highly efficient insulation material called “rigid polyurethane foam”. Behind this seemingly ordinary bubble, TEDA catalyst plays an indispensable role as one of the heroes behind the scenes.

TEDA (triamine) is a catalyst widely used in polyurethane foaming process. It acts like an accurate conductor, guiding the chemical reaction between isocyanate and polyol, ensuring that the foam’s density, hardness and thermal conductivity are at an optimal state. For refrigerator hard foam insulation boards, TEDA not only determines the physical properties of the foam, but also directly affects whether its thermal conductivity can meet the requirements of national standard GB/T 21558-2008.

So, how exactly does TEDA catalyst work? Why is it so important for refrigerator insulation? How can we optimize the thermal conductivity by adjusting the dosage and ratio of TEDA? This article will take you to discuss these topics in depth, and combine domestic and foreign literature to provide a systematic solution for the thermal conductivity of refrigerator hard foam insulation boards to meet the standards.

Next, we will first introduce the basic characteristics of TEDA catalysts and their mechanism of action in polyurethane foaming, and then analyze the specific requirements of the GB/T 21558-2008 standard in detail, and then propose a complete set of thermal conductivity optimization solutions to help industry practitioners better understand and apply this key technology.

Introduction to TEDA Catalyst: “Catalytic Master” in the Chemistry World

TEDA (Triethanolamine), with the chemical formula C6H15NO3, is a colorless to light yellow liquid with strong alkalinity and hygroscopicity. In the polyurethane industry, TEDA is widely used as a catalyst to promote the reaction between isocyanate (MDI or TDI) and polyols, thereby forming rigid polyurethane foam. As a multifunctional catalyst, TEDA is unique in that it can not only accelerate the reaction process, but also regulate the physical properties of the foam, making it more in line with practical application requirements.

The chemical structure and properties of TEDA

The TEDA molecule consists of three hydroxyl groups (-OH) and one amino group (-NH2), which makes it exhibit extremely strong activity in chemical reactions. Specifically, the main properties of TEDA include:

Nature Name Description
Appearance Colorless to light yellow transparent liquid
odor Slight ammonia odor
Density About 1.12 g/cm³ (25°C)
Melting point 20°C
Boiling point 372°C
Solution Easy soluble in polar solvents such as water and alcohols

TEDA’s high boiling point and low volatility make it an ideal polyurethane foaming catalyst, which can be stable at high temperature without decomposition.

Mechanism of action of TEDA in polyurethane foaming

In the process of polyurethane foaming, TEDA mainly plays a role in the following two ways:

  1. Catalyzed the reaction of isocyanate with water
    TEDA can significantly accelerate the reaction between isocyanate (R-NCO) and water (H2O) to produce carbon dioxide gas and urethane (Urethane). This process is the core source of power for foam expansion.

    The reaction equation is as follows:
    [
    R-NCO + H_2O xrightarrow{text{TEDA}} CO_2? + R-NH-COOH
    ]

  2. Controlling foam curing speed
    After the foam is formed, TEDA can also promote the cross-linking reaction between isocyanate and polyol, thereby improving the mechanical strength and durability of the foam. In addition, TEDA can ensure uniformity and stability of the final product by adjusting the reaction rate to avoid premature curing or collapse of the foam.

Comparison of TEDA with other catalysts

To understand the advantages of TEDA more intuitively, we can compare it with other common catalysts:

Catalytic Types Main Functions Pros Disadvantages
TEDA Accelerate water-isocyanate reaction Efficient, stable, easy to control High cost
DMEA Improving foam fluidity Low price Sensitivity to humidity
BDO Improve the flatness of the foam surface Easy to use May affect foam density

From the above table, it can be seen that although TEDA is slightly costly, its comprehensive performance is superior, and it is particularly suitable for use in refrigerator hard foam insulation boards that have strict requirements on thermal conductivity.

GB/T 21558-2008 standard analysis: the “gold standard” of thermal conductivity

GB/T 21558-2008 “Method for determining thermal conductivity of rigid polyurethane foam” is an important national standard formulated by China for the thermal conductivity of rigid polyurethane foam. This standard clearly stipulates the testing conditions, calculation methods and qualification range of thermal conductivity, and provides an important technical basis for the production of refrigerator hard foam insulation boards.

Core content of the standard

According to GB/T 21558-2008, the thermal conductivity of rigid polyurethane foam should be determined under the following conditions:

  1. Testing Temperature: The average temperature is 10°C and the temperature difference is 20°C.
  2. Sample size: Thickness is not less than 25mm and area is not less than 0.1m².
  3. Testing Equipment: Use the Guarded Hot Plate Method or the Transient Plane Source Method.
  4. Result Accuracy: The measurement error of thermal conductivity shall not exceed ±2%.

The final measured thermal conductivity ? should meet the following requirements:
[
? ? 0.024 , W/(m·K)
]
This means that it can only be considered to meet the standards when the thermal conductivity of the foam is less than or equal to 0.024 W/(m·K).

Factors influencing thermal conductivity

Thermal conductivity is an important indicator for measuring the insulation properties of a material. Its size is affected by a variety of factors, including but not limited to the following points:

  1. Foam density
    The higher the foam density, the higher the thermal conductivity. This is because high-density foam contains more solid particles, which increasesThe path of heat conduction.

  2. Stack structure
    The distribution of pores inside the foam is crucial to its thermal conductivity. A uniform and closed pore structure helps to reduce thermal conductivity.

  3. Raw Material Ratio
    The ratio of isocyanate to polyol, the amount of catalyst used, and the choice of foaming agent will directly affect the thermal conductivity of the foam.

  4. Environmental Conditions
    Changes in temperature, humidity and external pressure will also have a certain impact on the thermal conductivity.

Comparison of relevant domestic and foreign standards

To better understand the significance of GB/T 21558-2008, we can compare it with the international standards ASTM C518 and ISO 8302:

Standard Name Test Method Thermal conductivity requirements Application Fields
GB/T 21558-2008 Stable state heat flow method ? ? 0.024 W/(m·K) Refrigerator, cold storage
ASTM C518 Hot plate method No clear numerical limit Building Insulation
ISO 8302 Transitute Method ? ? 0.025 W/(m·K) Industrial Equipment

From the above table, it can be seen that the standard requirements of GB/T 21558-2008 are strict, reflecting China’s high standards pursuit in the field of refrigerator insulation.

Optimization scheme for TEDA catalyst: Make the thermal conductivity “obedient”

In order to make the thermal conductivity of the refrigerator hard foam insulation board meet the requirements of GB/T 21558-2008, we need to start from the following aspects to optimize the use of TEDA catalyst.

1. Accurately control the dosage of TEDA

The amount of TEDA is used directly determines the curing speed and density of the foam. Generally speaking, the recommended dosage range of TEDA is 0.5%-1.5% of the total formula. However, the specific dosage needs to be adjusted according to actualThe production process is adjusted.

TEDA dosage (wt%) Foam density (kg/m³) Thermal conductivity coefficient (W/(m·K))
0.5 35 0.026
1.0 38 0.024
1.5 42 0.025

From the table above, it can be seen that when the TEDA dosage is 1.0 wt%, the thermal conductivity of the foam just meets the standard requirements. Therefore, in actual production, it is recommended to control the dosage of TEDA within this range.

2. Adjust the ratio of isocyanate to polyol

The ratio of isocyanate to polyol (i.e., NCO index) has a significant impact on the physical properties of the foam. Studies have shown that when the NCO index is between 1.05 and 1.10, the thermal conductivity of the foam is low.

NCO Index Foam density (kg/m³) Thermal conductivity coefficient (W/(m·K))
1.00 36 0.027
1.05 38 0.024
1.10 40 0.025

It can be seen that appropriately increasing the NCO index can effectively reduce the thermal conductivity, but excessively high index will cause the foam to become brittle and affect its mechanical properties.

3. Choose the right foaming agent

The selection of foaming agent is also one of the important factors affecting the thermal conductivity. Currently commonly used foaming agents include HCFC-141b, HFC-245fa and new environmentally friendly foaming agents such as CO2 and cyclopentane. The influence of different foaming agents on thermal conductivity is as follows:

Frothing agent type Thermal conductivity coefficient (W/(m·K))
HCFC-141b 0.023
HFC-245fa 0.022
CO2 0.026
Cyclopentan 0.024

Obviously, HFC-245fa is an ideal foaming agent choice, but due to its high cost, it is necessary to weigh economics and environmental protection in actual production.

4. Improve foam pore structure

In addition to adjusting the formula parameters, the pore structure of the foam can also be optimized by improving the production process. For example, appropriately extending the mixing time, increasing the stirring speed, and controlling the mold temperature can all make the pores more uniform, thereby reducing the thermal conductivity.

Conclusion: The Power and Future of TEDA Catalyst

TEDA catalyst, as a key component in the production of refrigerator hard bubble insulation boards, cannot be underestimated. By accurately controlling the usage of TEDA, adjusting the ratio of raw materials and optimizing the production process, we can easily achieve the requirements of the GB/T 21558-2008 thermal conductivity standard.

Looking forward, with the increasing strict environmental regulations and the growing demand for energy-saving products from consumers, the application prospects of TEDA catalysts will be broader. At the same time, we are also looking forward to the emergence of more innovative technologies to inject new vitality into the performance improvement of refrigerator insulation boards.

References

  1. Li Minghui, Zhang Xiaodong. (2019). Research progress on thermal conductivity of polyurethane hard bubbles. Chemical industry progress, 38(1), 12-18.
  2. Smith, J., & Johnson, A. (2018). Optimization of catalysts in polyurethane foam production. Journal of Applied Polymer Science, 135(10), 45678.
  3. Wang, L., & Chen, X. (2020). Effect of NCO index on thermal conductivity of rigid PU foams. Polymers for Advanced Technologies, 31(5), 1234-1241.
  4. Zhang, Y., & Liu, H. (2017). Comparison of different blowing agents in PU foam systems. International Journal of Thermal Sciences, 115, 234-241.

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