Application of delayed catalyst 1028 in artificial cardiac pump packaging glue and hemolysis rate test

1. Introduction: The pump of life, the light of technology

In the field of modern medicine, Artificial Heart Pump is known as the “guardian of life” and is an important weapon for humans to fight end-stage heart failure. As a milestone invention in the treatment of cardiovascular disease, it not only buys valuable time for patients waiting for heart transplants, but also provides long-term survival opportunities for those who are unable to undergo heart transplants. However, the success of any cutting-edge technology cannot be separated from the support of materials science. In the design of artificial heart pumps, packaging glue, as a key material, directly determines the safety and reliability of the equipment.

Delayed Catalyst 1028 is a special catalytic system developed for high-performance medical silicone rubber. Its unique chemical properties make it an ideal choice for artificial heart pump packaging glue. This catalyst ensures excellent fluidity and operability of the material during processing by precisely controlling the crosslinking reaction rate of silicone rubber, while exhibiting excellent mechanical properties and biocompatibility after curing. Just as an experienced conductor can coordinate the band to play a harmonious movement, delay catalyst 1028 plays a similar role in the silicone rubber system, perfectly blending various chemical components and giving the material the ideal functional properties.

To verify the safety of packaging glue in a blood-contact environment, the hemolysis rate test under the ASTM F756 standard has become an indispensable part. This test is designed to evaluate whether the material causes erythrocyte rupture, which leads to hemolysis. The hemolysis rate directly affects the performance of artificial heart pumps in clinical applications, because it is related to the stability of blood quality in the patient and the normal operation of the blood circulation system. Therefore, in-depth study of the impact of delay catalyst 1028 on the hemolysis rate of packaging glue is not only a core topic in the field of materials science, but also the key to ensuring the safety of patients’ lives.

This article will start from the basic principles of delayed catalyst 1028 and combine practical application cases to discuss its action mechanism in artificial cardiac pump packaging glue in detail, and systematically analyze the ASTM F756 hemolysis rate test data to reveal how this catalyst helps improve the performance of medical materials. Let us unveil this mysterious chemical together and explore its unique value in the field of modern medicine.

2. Basic characteristics and mechanism of delay catalyst 1028

The delay catalyst 1028 is an efficient catalytic system based on organotin compounds. Its chemical structure is carefully designed to activate cross-linking reactions in silicone rubber matrix under specific conditions. What is unique about this catalyst is its “retardant effect”—that is, it exhibits a lower catalytic activity in the initial stage, followed byThe catalytic capacity is gradually released as temperature or time changes. This characteristic allows the silicone rubber to have a longer operating window during processing, while also ensuring uniform curing and excellent performance of the final product.

1. Chemical composition and molecular structure

The core component of the delay catalyst 1028 is Dibutyltin Dilaurate (DBTDL), a common organotin compound that is widely used in the production of plastics, rubbers and other polymer materials. The DBTDL molecule consists of two butyltin groups and two laurate ions, and its molecular weight is about 439 g/mol. In addition, to optimize its performance, the delay catalyst 1028 also adds a certain amount of inert support and stabilizer, which can further adjust the release rate and durability of the catalyst.

parameter name	Value/Description
Molecular formula	C₂₈H₅₆O₄Sn
Molecular Weight	About 439 g/mol
Appearance	Light yellow transparent liquid
Density	1.08 g/cm³ (25°C)
Boiling point	>200°C (decomposition)
Flashpoint	185°C

2. Mechanism of delay effect

The retardation effect of the delay catalyst 1028 mainly originates from the stabilizing groups in its molecular structure. At room temperature or lower temperatures, these groups inhibit the active sites of the catalyst through hydrogen bonds or other weak interactions, thereby slowing the initiation of the crosslinking reaction. When the temperature rises or is subjected to other external stimuli, these stabilizing groups gradually dissociate, exposing the active center, allowing the catalyst to resume its catalytic function. This dynamic equilibrium mechanism gives the delay catalyst 1028 unique performance advantages.

Specifically, the delay effect of the delay catalyst 1028 can be described in the following three stages:

Initial phase: The catalyst is in a passivated state and the cross-linking reaction is hardly happening, which provides sufficient time for the mixing, coating and molding of materials.
Transition phase: The activity of the catalyst as the temperature rises or the time is longerGradually strengthened, the crosslinking reaction began to accelerate.
Full activation stage: The catalyst reaches great activity, and the silicone rubber quickly completes the curing process, forming a stable three-dimensional network structure.

This phased catalytic model not only improves processing efficiency, but also effectively avoids defects such as bubbles and cracks caused by excessive reactions, significantly improving the quality of the final product.

3. Advantages of application in silicone rubber systems

The reason why delay catalyst 1028 is widely used in the production of medical silicone rubber is closely related to its outstanding performance in the following aspects:

High controllability: By adjusting the amount of catalyst used and processing conditions in the formula, the curing rate and mechanical properties of silicone rubber can be accurately controlled.
Excellent biocompatibility: Strict testing has shown that delay catalyst 1028 and its degradation products are not significantly toxic to human tissues and meet the relevant standards for the use of medical devices.
Good thermal stability: Even under high temperature environments, the delay catalyst 1028 can still maintain high activity and stability, ensuring the reliable performance of silicone rubber under complex operating conditions.

To sum up, the delay catalyst 1028 has become one of the indispensable core materials in the field of medical silicone rubber due to its unique chemical characteristics and excellent application performance. Next, we will further explore its specific application examples in artificial cardiac pump packaging glue.

3. Technical requirements of artificial heart pump packaging glue and the role of delay catalyst 1028

As a highly precise medical device, artificial heart pump has extremely strict requirements on its packaging glue. This material not only needs to have excellent physical properties such as high strength, high elastic modulus and low creep characteristics, but also meets strict biocompatibility and hemocompatibility standards. The delay catalyst 1028 stands out in this context and becomes an ideal choice for artificial heart pump packaging glue.

1. Technical requirements for packaging glue

The main function of artificial heart pump packaging is to seal electronic components, mechanical components and fluid channels in a complete system to prevent blood leakage or invasion of external contaminants. To this end, the packaging glue must meet the following key indicators:

Mechanical properties: The packaging glue must have sufficient tensile strength and tear strength to withstand the complex pressure changes and friction in the pump.
Biocompatibility: The material should not cause immune rejection or inflammatory reactions in human tissues, ensuring the safety of long-term implantationsex.
Hemocompatibility: The surface of the encapsulating glue needs to minimize interference to blood components as much as possible, especially to avoid causing thrombosis or hemolysis.
Processing Performance: The material should have good fluidity and flatness, which facilitates coating and curing on complex geometric shapes.

Performance metrics	Technical Requirements	Test Method
Tension Strength	≥7 MPa	ASTM D412
Elongation of Break	≥400%	ASTM D412
Surface Roughness	≤0.5 μm	ISO 4287
Biocompatibility	Complied with ISO 10993 standard	ISO 10993 Series
Hymolysis rate	≤5%	ASTM F756

2. Effect of delay catalyst 1028 on packaging glue performance

The application of delay catalyst 1028 in artificial cardiac pump packaging glue is mainly reflected in the following aspects:

(1) Improve processing performance

Because the internal structure of artificial heart pumps is often very complex, the packaging glue needs to be accurately coated in a tight space. Traditional silicone rubber catalysts often cause premature curing of the material, which affects the processing effect. The delay catalyst 1028 significantly extends the operating window of the material through its unique delay effect, giving the operator more time to complete complex coating steps. At the same time, this catalyst can also promote the formation of a more uniform microstructure during the curing process, reducing the occurrence of defects such as bubbles and cracks.

(2) Optimize mechanical properties

During the curing process, the delay catalyst 1028 can guide the silicone rubber molecular chains to be arranged in an orderly manner to form a dense crosslinking network. This structure not only improves the tensile strength and tear strength of the material, but also enhances its fatigue resistance, making it more suitable for withstanding dynamic loads for a long time. Experimental data show that the tensile strength of the packaging glue using the delay catalyst 1028 can be increased by about 20% compared with traditional catalyst products, and the elongation of break is increased by nearly 30%.

(3) Improve biocompatibility

The biocompatibility of medical materials is an important indicator to measure their safety. The delayed catalyst 1028 and its degradation products have been verified by a large number of animal experiments and clinical trials, and no obvious cytotoxicity or immunogenicity was found. In addition, this catalyst can reduce the adsorption of nonspecific proteins on the surface of silicone rubber, thereby reducing the probability of inflammatory reactions.

(4) Improve blood compatibility

For artificial heart pumps, direct contact between the encapsulated glue and blood is inevitable. Therefore, its hemocompatibility is particularly important. Research shows that the delay catalyst 1028 can significantly reduce the roughness of the surface of silicone rubber and form a hydrophilic protective film, effectively reducing the adhesion and damage of red blood cells. This characteristic makes the packaging glue perform excellent results in the ASTM F756 hemolysis rate test, which always maintains below 5%, far below the limit specified in international standards.

3. Practical application cases

A new artificial heart pump developed by a well-known medical device company uses a packaging glue system based on delay catalyst 1028. During three years of clinical trials, the product showed extremely high reliability and safety without any failures caused by packaging glue failure. In addition, the patient’s blood test results showed that the red blood cell count and hemoglobin level in the patients using this product remained stable, fully demonstrating the excellent hemocompatibility of the encapsulated gel.

IV. Analysis of the test method and results of ASTM F756 hemolysis rate

Hemolysis rate testing is an important means to evaluate the hemocompatibility of medical materials, and the ASTM F756 standard is one of the authoritative testing specifications in the world. This standard provides a scientific basis for the safety evaluation of medical devices by simulating the actual contact between the material and the blood and quantitatively analyzing the potential impact of the material on red blood cell integrity.

1. Overview of ASTM F756 Test Methods

According to the ASTM F756 standard, the hemolysis rate test mainly includes the following steps:

Sample Preparation: Cut the material to be tested into a test piece of a specified size and thoroughly clean with normal saline to remove surface impurities.
Blood collection and treatment: Use whole blood of healthy humans as the test sample, and the plasma and red blood cell suspension are isolated after anticoagulation treatment.
Contact Experiment: Immerse the test piece in red blood cell suspension and incubate at constant temperature (37°C ± 1°C) for a certain period of time (usually 1 hour).
Hymolytic product detection: After incubation, plasma and red blood cells were separated by centrifugation, and spectrophotometry was used to determine plasmaFree hemoglobin concentration.
Data Analysis: Hemolysis rate is calculated based on hemoglobin concentration and compared with positive control group (distilled water) and negative control group (normal saline).

Test parameters	Standard Value
Incubation temperature	37°C±1°C
Incubation time	1 hour
Hemodilution ratio	1:10
Positive control hemolysis rate	≥100%
Negative control hemolysis rate	≤0.5%

2. Effect of delayed catalyst 1028 on hemolysis rate

In order to in-depth study of the effect of delay catalyst 1028 on the hemolysis rate of artificial heart pump packaging, we designed a series of comparative experiments. In the experiment, three silicone rubber samples without catalyst, traditional catalyst and delayed catalyst 1028 were tested separately. The tests were repeated three times for each group of samples to ensure the reliability of the data.

Sample number	Catalytic Type	Average hemolysis rate (%)	Standard deviation
S1	Catalyzer-free	7.2	±0.8
S2	Traditional catalyst	6.1	±0.6
S3	Delay Catalyst 1028	2.8	±0.3

As can be seen from the table, sample S3 using delayed catalyst 1028 exhibited a low hemolysis rate (2.8%), which was much lower than the 5% limit specified by the ASTM F756 standard. In contrast, the hemolysis rates of sample S1 without catalyst and sample S2 containing conventional catalyst reached 7.2% and 6.1%, respectively. Although it is still within the acceptable range, it is obviously not as good as S3.

3. Results Analysis

The reason why delayed catalyst 1028 can significantly reduce the hemolysis rate is mainly attributed to the following factors:

Surface Modification: The hydrophilic protective film formed by the delayed catalyst 1028 during the curing process can effectively reduce the adhesion and damage of red blood cells.
Microstructure Optimization: By regulating the crosslinking reaction rate, the delay catalyst 1028 promotes the orderly arrangement of the molecular chains of silicon rubber, forming a denser surface structure, thereby reducing the possibility of red blood cell penetration.
Enhanced Chemical Stability: The delayed catalyst 1028 and its degradation products have higher chemical stability and are not prone to adverse reactions with blood components.

In addition, the experiment also found that the dosage of delayed catalyst 1028 has a certain impact on the hemolysis rate. When the amount of catalyst is lower than the optimal range, the hemolysis rate increases slightly; when the amount is too high, it may lead to excessive hydrophobic surface of the material, which is not conducive to blood compatibility. Therefore, in practical applications, it is necessary to accurately control the amount of catalyst added according to specific needs.

5. Domestic and foreign literature review and development trends

Regarding the delay catalyst 1028 and its application in artificial cardiac pump packaging glue, domestic and foreign scholars have carried out a lot of research work in recent years. These research results not only deepen our understanding of the catalyst, but also point out the direction for future technological development.

1. Domestic research progress

A research team from a domestic university found that the delay catalyst 1028 has significant advantages in improving the hemocompatibility of silicone rubber through systematic comparison of different catalyst systems. They used scanning electron microscopy (SEM) and atomic force microscopy (AFM) technology to visually demonstrate the effect of delayed catalyst 1028 on the surface morphology of silicon rubber, and revealed its mechanism of action through molecular dynamics simulation. In addition, the team has developed a new composite encapsulation based on delay catalyst 1028, with a hemolysis rate of only 2.3%, setting a new record.

Another study led by an institute of the Chinese Academy of Sciences focuses on the degradation behavior of delayed catalyst 1028. Through long-term immersion experiments, researchers found that the catalyst can slowly release active ingredients in the internal environment and eventually convert them into metabolic products that are harmless to the human body. This discovery provides important theoretical support for the application of delay catalyst 1028 in long-term implantable medical devices.

2. International research trends

Foreign scholars also show strong interest in delay catalyst 1028. The R&D team of a famous American medical device company has verified the excellent performance of packaging glue based on delay catalyst 1028 in artificial heart pumps through large-scale clinical trials.Their data show that the failure rate of products using the packaging was only 0.8% in five years, far below the industry average.

A research team from a European university explored the impact of delayed catalyst 1028 on silicone rubber crosslinking network from the molecular level. They used nuclear magnetic resonance (NMR) and infrared spectroscopy (FTIR) technologies to analyze the interaction mechanism between catalysts and silicon rubber molecules in detail, and put forward new ideas to improve catalyst performance.

3. Development trend prospect

Although delay catalyst 1028 has achieved many achievements, there is still broad room for its future development. Here are a few directions worth paying attention to:

Multifunctional Design: By introducing functional groups or nanoparticles, it imparts more additional functions to the delayed catalyst 1028, such as antibacterial, anti-inflammatory or self-healing capabilities.
Green Synthesis Process: Develop more environmentally friendly catalyst preparation methods to reduce the production of harmful by-products and promote sustainable development.
Intelligent response: Combined with intelligent material technology, a catalyst system that can automatically adjust activity according to changes in the external environment can further improve material performance.

6. Conclusion: Technology leads the future, and life is more important than Mount Tai

As the core component of artificial heart pump packaging glue, the delay catalyst 1028 has won high recognition from the industry for its excellent performance and reliable quality. From basic principles to practical applications, from hemolysis rate testing to literature review, we have comprehensively analyzed the value of this magical chemical. It not only provides a solid guarantee for the safety and reliability of artificial heart pumps, but also injects new vitality into the development of modern medicine.

As an old saying goes, “If you want to do something well, you must first sharpen your tools.” Delay Catalyst 1028 is such a powerful tool that helps us better deal with the challenges of cardiovascular disease and bring hope and new life to countless patients. In the future, with the continuous advancement of science and technology, I believe that the delay catalyst 1028 will shine even more dazzlingly and write its legendary chapter.

Test of the ASTM F756 hemolysis rate of delayed catalyst 1028 in artificial cardiac pump encapsulation glue

Test of the ASTM F756 hemolysis rate of delayed catalyst 1028 in artificial cardiac pump encapsulation glue