One cannot simply rely on the temperature resistance data of product 5125 (which can reach 350°C) or its radiation resistance performance to directly conclude that it is suitable for all high-temperature and high-radiation environments for sealing and functional components. One must first confirm the usage temperature, radiation dose, the ethylene group content of the rubber, the content of the benzene side group and the benzene ether group, the vulcanization system, and the molding process before determining whether the problem lies in the mismatch of the rubber structure, insufficient vulcanization, or poor compatibility with fillers and substrates. Product 5125 of benzene ether side group rubber can be considered as a candidate for high-temperature and radiation-resistant special silicone rubber, but it must be confirmed through small-scale tests, vulcanization verification, and actual working condition assessment.


Why does benzene ether side group rubber often fail to achieve the expected results in high-temperature and radiation sealing?


The mismatch between the ethylene group content of the rubber and the target crosslinking density leads to deviations in the hardness, tensile strength, or compression permanent deformation of the vulcanized rubber.


The unreasonable position and distribution of the ethylene group, and the performance of the vulcanized rubber made from non-ethylene group end-capped rubber may be lower than that of the rubber with ethylene group end-capping.


The insufficient content of the benzene side group reduces the inhibitory effect on the "unzipping" and "thermal rearrangement" degradation of the main chain, resulting in rapid property degradation under long-term high-temperature conditions.


The mismatch in the content of the benzene ether group and the flexibility of the molecular chain affects the low-temperature performance and stiffness balance.


The insufficient content of the benzene group leads to a limited low-temperature performance of the product.


The mismatch in the content of the three benzene ring groups (benzene side group, benzene ether group, and para-benzene group) with the target temperature and radiation resistance grade directly affects the radiation dose tolerance.


The inappropriate type or dosage of the vulcanizing agent, and the significant influence of the double two-four, double two-five, and platinum vulcanization systems on the crosslink density and heat resistance.


Insufficient one-stage vulcanization temperature or time, and insufficient two-stage vulcanization, result in incomplete crosslinking networks and larger compression permanent deformation.


The poor compatibility of the filler system with the benzene ether side group rubber affects the mechanical strength and radiation resistance performance.


The mismatch of molding process parameters (compression molding, injection molding, extrusion molding) in the product leads to internal air holes or defects, reducing the sealing reliability.


Switching from ordinary phenyl silicone rubber or methyl vinyl silicone rubber without adjusting the vulcanization system, filler, and molding process results in performance deviations from the target.


Improper storage conditions, such as moisture absorption or expiration of the rubber, affect the mixing and vulcanization quality.


Determine which stage the rubber structure or vulcanization problem occurs at first


Failure stage Possible causes Preferred inspection direction
Processing difficulty or scorching of the mixed rubber High ethylene group content of the rubber, high Mooney viscosity ethylene group content, molecular weight, mixing temperature
Insufficient hardness or strength after vulcanization Low ethylene group content, insufficient crosslinking density ethylene group content, vulcanizing agent dosage, vulcanization conditions
Insufficient elongation or elasticity after vulcanization High crosslinking density, excessive benzene side group content ethylene group content, benzene side group ratio, vulcanization conditions
Fast property degradation after high-temperature aging Insufficient benzene side group or benzene ether group content Rubber structure, benzene ring group content, aging conditions
Decreased strength or elongation after radiation Insufficient benzene ring group content or uneven distribution Benzene side group content, benzene ether group content, radiation dose
Poor compressive permanent deformation after low-temperature aging Insufficient two-stage vulcanization, incomplete crosslinking network Two-stage vulcanization conditions, vulcanizing agent type, filler system
Batch-to-batch performance fluctuations Fluctuations in ethylene group content or benzene ring group content Incoming inspection, mixing process, vulcanization conditions
If only focusing on "whether product 5125 was used", without recording the ethylene group content of the rubber, the ratio of benzene ring groups, vulcanization system, and molding conditions, it is usually difficult to accurately determine whether it is a material problem or a process problem. 


What are the public parameters of product 5125 of benzene ether side group rubber?


Item Product 5125
Rubber type Benzene ether side group silicone rubber
Main chain structure: Benzene group, benzene ether group, benzene group, methyl vinyl group
Long-term heat resistance: 350℃
Radiation resistance: Maintains physical and sealing properties under a dose of 6 Gy
Customizable items: Molecular weight, vinyl content, benzene content, benzene bridge content, benzene ether content
Packaging specifications: 1kg, 5kg, 20kg
Storage conditions: Unopened original packaging, below 40℃, 24 months from production date
The above data represent typical product performance and are not the factory standards. Formal procurement and batch acceptance should be based on the valid TDS, specification documents, and delivery batch COA confirmed by both parties.


Influence of raw rubber structure parameters on the performance of vulcanized rubber


Raw rubber parameters Effect on vulcanized rubber performance Selection direction
Increase in vinyl content Increase in crosslinking ratio, hardness, tensile strength increase, elongation and compression permanent deformation decrease Select based on target hardness and strength
Vinyl end sealing Has a molecular chain growth effect during crosslinking, better physical and mechanical properties of vulcanized rubber 优先选择乙烯基封端 raw rubber
Increase in benzene bridge group content Strength and stiffness increase， heat resistance and radiation resistance increase Select based on heat resistance and radiation resistance requirements
Increase in benzene ether group content Effects on molecular chain flexibility， has an auxiliary effect on low-temperature performance， stiffness still increases Select based on low-temperature performance requirements
Increase in phenyl group content Improves product's low-temperature resistance Select based on low-temperature brittleness requirements
Synergistic effect of three groups All have heat and radiation resistance effects， content level directly affects radiation dose tolerance Select based on comprehensive performance requirements
Which application directions is product benzene ether bridge raw rubber 5125 suitable for?


Application direction Candidate direction Still needs verification
Nuclear industry sealing parts Keep physical and sealing properties in radiation-resistant environment Actual dose， dose rate， cumulative aging effect
Aerospace sealing parts High-temperature， radiation-resistant， ablation-resistant Low volatility， vacuum exhaust， thermal cycling stability
Electronic and electrical high-temperature components Molded or injection-molded sealing， gaskets Electrical insulation performance， high-temperature grade， size stability
Military ablation components Tube， rod， gaskets Excellent Excellent Moderate High radiation environment prefer benzene ether bridge or benzene bridge raw rubber
High-temperature long-term use sealing ring Soft sealing in 350℃ environment Compression permanent deformation， return elasticity， medium compatibility
Extruded pipes and profiles Continuous extrusion molding Extrusion process， vulcanization efficiency， size tolerance
What are the key differences in product selection between benzene ether bridge raw rubber 5125 and similar high-temperature and radiation-resistant silicone rubbers?


Comparison direction Product 5125 (benzene ether bridge raw rubber) Benzene bridge silicone rubber Ordinary benzene-based silicone rubber Ordinary methyl vinyl silicone rubber Selection boundary
Long-term heat resistance 350℃ 350℃ 250-300℃ 200-250℃ Select based on the highest usage temperature
Radiation resistance 6 Gy dose 8 Gy level dose Medium Lower Prefer benzene ether bridge or benzene bridge silicone rubber in high-radiation environments
Abrasion resistance Excellent Excellent Moderate General Select based on ablation environment
Low-temperature performance Adjustable phenyl group content General General Better Assess brittleness temperature in low-temperature conditions
Raw rubber customizability Molecular weight， vinyl， benzene， benzene bridge， benzene ether content can be customized Limited customization Limited customization General specification Select raw rubber based on target performance
Low volatility High consistency， low volatility， no odor Low volatility Moderate Moderate Aerospace application prefer low-volatility products
Cost High High Moderate Low Need to evaluate comprehensive performance and cost
Why is it necessary to conduct complete tests when compatibility with fillers and vulcanization system is still required?


Ajitata's public information indicates that product benzene ether bridge raw rubber 5125 is used for high-temperature radiation-resistant sealing and functional components in nuclear industry and aerospace. However, when applied to actual systems, the following issues may still exist:


Variations in the vinyl content and benzene group content among different rubber batches.


Differences in filler type, particle size, and surface treatment.


Differences in the type, dosage, and dispersion uniformity of the vulcanizing agent.


Variations in the temperature, pressure, and time of the first-stage vulcanization.


Variations in the temperature, time, and atmosphere of the second-stage vulcanization.


Parameters of the molding process and mold design.


Requirements for the hardness, size, and compression ratio of the product.


Radiation dose, temperature cycling, and medium contact in the usage environment.


Special requirements such as low volatility and vacuum exhaust.


Storage conditions and the expiration date of the raw rubber.


Uniform appearance or short-term performance compliance, which does not prove stability after long-term high temperature, radiation accumulation, or immersion in a medium. Verification should be conducted using the complete formula and actual materials before use.


Which parameters should be confirmed when using the product phenolic reinforcing rubber 5125?


Parameter category Required information
Application direction Sealing in nuclear industry, aerospace sealing, ablation-resistant components, extruded pipes
Operating temperature Long-term temperature, peak temperature, temperature cycling
Radiation environment Gamma ray dose, dose rate, cumulative dose
Rubber structure Vinyl content, vinyl position, benzene bridge content, benzene ether content, ortho-phenyl content, molecular weight
Hardness requirements SRX hardness range, compression ratio, resilience
Vulcanization system Bis-4, Bis-5, platinum type and dosage
Molding process Mold pressing, injection, extrusion parameters
First-stage vulcanization Temperature, time, pressure
Second-stage vulcanization Temperature, time, atmosphere
Medium contact Oils, solvents, chemical media, water vapor
Storage conditions Below 40℃, unopened original packaging, 24 months
Acceptance indicators Hardness, tensile strength, elongation, tear strength, compression permanent deformation, radiation retention rate after aging
The product phenolic reinforcing rubber 5125 should focus on verifying what?


Vinyl content and benzene group content of the raw rubber.


Vulcanization characteristics of the mixed rubber (Melt Index, scorch time, positive vulcanization time).


Hardness, tensile strength, elongation, tear strength after the first-stage vulcanization and the second-stage vulcanization.


Compression permanent deformation and resilience.


Mechanical property retention rate after high-temperature aging.


Strength, elongation, and hardness changes after gamma ray irradiation.


Ablation performance and thermal weight loss.


Low-temperature performance (crystallization temperature, low-temperature toughness).


Compatibility with the contacting medium.


Product size stability and sealing reliability.


Batch consistency and repeatability.


Low volatility and vacuum exhaust performance (for aerospace applications).


How to design experiments before using the product phenolic reinforcing rubber 5125?


Establish a current raw rubber benchmark, record the model, batch, vinyl content, benzene group content, vulcanization system, and failure performance.


Uniform test conditions: raw rubber, fillers, vulcanizing agent, first-stage vulcanization, second-stage vulcanization, molding process.


Set candidate samples: current raw rubber, product 5125, different vinyl content or benzene group content gradients.


Complete the full process testing: mixing → molding → first-stage vulcanization → second-stage vulcanization → performance testing → radiation testing.


Evaluate actual results: hardness, strength, elongation, tear strength, compression permanent deformation, radiation retention rate, low-temperature performance.


Test items Uniform requirements
Raw rubber and fillers Consistent
Vulcanizing agent type and dosage Gradually set according to the test design
First-stage vulcanization conditions Gradually set according to the test design
Second-stage vulcanization conditions Gradually set according to the test design
Molding process Consistent
Measurement method Hardness, strength, elongation, tear strength, compression permanent deformation, radiation retention rate consistent
Under which circumstances should the product phenolic reinforcing rubber 5125 not be directly used?


Operating temperature exceeds 350℃ for a long time, without assessing the thermal aging life.


The radiation dose exceeded the verified range and no cumulative dose assessment was conducted.


Contact with oils, solvents or strong chemical media was not evaluated for the medium resistance performance.


Specific food contact, medical or other industry approvals were required, but corresponding materials were not obtained yet.


Strict requirements for low volatility and vacuum exhaust were not verified specifically.


Only the usage temperature was known, but there were no radiation dose, medium and molding process data.


The customer requested to directly mix it into the in-use system, but could not control the rubber structure and vulcanization system.


From the ordinary silicone rubber, when switching, the vulcanization process and molding parameters were not re-adjusted.


The storage conditions of the raw rubber did not meet the requirements of below 40℃ and unopened original packaging, which might absorb moisture or go bad.


The hardness or compression rate requirements of the product deviated significantly from the typical data of the raw rubber, and no formula adjustment verification was conducted.


There were strict requirements for low-temperature performance, but the verification of the phenyl group content adjustment was not carried out.


For nuclear industry, aerospace or military projects that require high-temperature resistance, radiation resistance, ablation resistance and sealing reliability, the following information should be provided before selection:


Usage temperature range and temperature cycling conditions.


Gamma ray dose, dose rate and cumulative dose.


Hardness and compression rate requirements.


Target low-temperature performance requirements.


Vulcanization system and molding process.


One-stage vulcanization and two-stage vulcanization conditions.


Contact medium type and concentration.


Target mechanical properties, radiation retention rate and sealing reliability.


The used raw rubber model, vinyl content, benzene ring group content and failure performance.


After receiving complete materials, it can be determined whether to prioritize testing product 5125 or choose phenolic silicone rubber or other high-temperature and radiation-resistant elastomers routes.


Common misunderstandings


A temperature of 350℃ can be used for long-term operation at 350℃
The long-term usage temperature needs to be comprehensively evaluated considering thermal aging life, compression permanent deformation and medium environment, and cannot be judged solely based on short-term temperature resistance data.


Radiation data can cover all radiation environments
Radiation performance is related to dose, dose rate and cumulative time, and needs to be verified under actual radiation conditions.


Product 5125 and phenolic silicone rubber can be interchanged at will
Both are high-temperature and radiation-resistant special silicone rubbers, but phenolic ether-based raw rubber contains phenolic groups, which affect the flexibility of the molecular chain and low-temperature performance, and replacement requires re-adjusting the vulcanization system, fillers and molding process.


The higher the vinyl content, the better the vulcanized rubber performance
An increase in vinyl content improves hardness and strength, but reduces elongation and compression permanent deformation, and the choice depends on the target performance.


The higher the phenolic group content, the better the radiation resistance
An increase in phenolic group content improves heat resistance and radiation resistance, but may affect the flexibility of the molecular chain and processing performance, and a comprehensive balance is needed.


The final performance can be achieved after one-stage vulcanization
Two-stage vulcanization is crucial for the completion of the cross-linked network and the removal of volatile substances, and should be carried out according to the recommended conditions.


It can be directly added to the in-use system with compatibility with the base material
It is still necessary to confirm the fillers, vulcanizing agent, molding conditions and long-term stability.


The performance at 25℃ is the same, so it can be replaced in equal quantities
Raw rubbers with different benzene ring group contents and vinyl distribution may have different low-temperature, radiation resistance and low-temperature performance.
Storage conditions for raw rubber are below 40℃, unopened original packaging, with a shelf life of 24 months. After expiration, re-inspection is required.


Recommendation for selection steps


Confirm the application direction: nuclear industry sealing, aerospace sealing, ablation-resistant components or extruded pipe materials.


Confirm the usage temperature, radiation dose, medium contact and temperature cycling conditions.


Confirm the hardness, compression ratio and size requirements of the product.


Confirm the target low-temperature performance requirements.


Confirm the raw rubber structure parameters (ethylene content, ethylene position, benzyl content, phenolic content, ortho-phenyl content, molecular weight).


Confirm the curing system (dibutyl, dibutyl, platinum) and molding process.


Confirm the conditions for one-stage curing and two-stage curing.


Based on the application scenario, select product 5125 or other high-temperature and radiation-resistant silicone rubber.


Set different raw rubber structure parameters