What key role do chemical rubber additives play in tire formulation?
Tires are essential core components of modern transportation, and their performance is directly related to driving safety, fuel efficiency and comfort. The performance optimization of tires depends not only on the material properties of rubber itself, but also on scientific and reasonable formula design, especially the application of various rubber additives. As an important component of tire formulation, chemical rubber additives play a vital role by regulating the cross-linking, aging resistance, wear resistance and other properties of rubber.
This article will start from the definition and classification of chemical rubber additives, focus on its specific functions and key roles in tire formulation, and explore the development trend of future tire additives in combination with actual production needs.
1. Special requirements for rubber properties in tire manufacturing
As a typical representative of rubber products, tires need to have a series of composite properties:
Wear resistance: ensure long tire life and road grip.
Elasticity and rebound performance: affect comfort and fuel efficiency.
Aging resistance and ozone resistance: extend service life and prevent rubber cracking.
Heat resistance: ensure stable performance under high-speed driving.
Processing performance: facilitate tire molding and vulcanization.
In order to meet these needs, the additive system, especially chemical additives, must be carefully designed in the tire formulation.
2. Definition and classification of chemical rubber additives
Chemical rubber additives refer to additives that improve rubber properties through chemical reactions, mainly including vulcanizers, vulcanization accelerators, antioxidants, antiozonants, crosslinkers, etc. They improve the physical properties and durability of tires by participating in or promoting crosslinking between rubber molecules and protecting rubber molecular chains.
Main categories:
Vulcanizers: such as sulfur, peroxides
Vulcanization accelerators: thiazoles, dithiocarbamates, etc.
Antioxidants: amines, phenolic antioxidants
Antiozonants: phosphine, carbamates
Crosslinking accelerators: such as silane coupling agents, etc.
3. The key role of chemical rubber additives in tire formulations
1. Promote rubber vulcanization crosslinking to form an elastic network structure
The combination of vulcanizers and accelerators is the core of tire manufacturing. Under the catalysis of vulcanization accelerators, vulcanizers (usually sulfur) promote the formation of sulfur bonds between rubber molecular chains to build a three-dimensional elastic network structure.
Effects:
Improve the elasticity and recovery ability of tires;
Enhance mechanical strength and wear resistance;
Improve heat resistance and chemical resistance.
The choice of different vulcanization systems affects the performance balance of tires. For example, the traditional sulfur system is suitable for general tires, and the peroxide vulcanization system is mostly used for high-temperature resistant tires.
2. Improve oxidation resistance and ozone resistance and extend tire life
During use, tires are inevitably exposed to oxygen and ozone in the air, which can easily cause rubber chains to break and cause surface cracking.
Antioxidants prevent oxidation chain reactions by capturing free radicals;
Antiozonants form a protective film to block ozone erosion.
These two types of additives effectively prevent tire aging and ensure safety and reliability for long-term use.
3. Improve the compatibility of fillers and rubber and enhance mechanical properties
A large amount of carbon black or silica gel is filled in the tire formula to enhance wear resistance and strength. Chemical additives such as silane coupling agents connect rubber molecules and filler surfaces through chemical bonds to improve interfacial bonding.
Effect:
Improve tire wear resistance and tensile strength;
Optimize rolling resistance and reduce fuel consumption;
Improve wet grip and achieve performance balance.
4. Regulate vulcanization speed and temperature to improve production efficiency and quality stability
Vulcanization accelerators regulate the activity of vulcanization reaction, shorten production cycle, and prevent over-vulcanization or under-vulcanization.
Reasonable ratio promotes uniform vulcanization and improves product consistency;
Shorten molding cycle and reduce production costs.
4. Analysis of the application of typical chemical additives in tires
Additive categories Typical varieties Key functions Application effects
Vulcanizers Sulfur cross-links rubber molecules to build an elastic network and improve strength
Accelerators CBS (o-phenylenediamine) accelerate vulcanization speed, shorten production cycle, and control vulcanization activity
Antioxidant 6PPD (amines) Anti-oxidation delays aging and increases service life
Anti-ozonants Carbamates resist ozone cracking and improve outdoor durability
Cross-linking accelerators Silane coupling agents promote filler bonding, improve mechanical properties, and reduce rolling resistance
5. Chemical additive optimization strategies in formula design
1. Balance between performance and cost
Different additives have large differences in performance and cost, and comprehensive considerations are needed when designing formulas:
High-performance additives improve performance but are costly;
Ordinary additives have low costs but limited performance.
Tire companies need to choose a reasonable combination of additives based on product positioning.
2. Environmental protection and regulatory requirements
As environmental regulations become stricter, additives containing volatile organic compounds (VOCs) or harmful substances are restricted, and green and environmentally friendly additives have become a trend.
3. Development and application of multifunctional additives
In order to simplify the formula and improve efficiency, composite additives with multiple functions (anti-oxidation, anti-ozone, and vulcanization promotion) are becoming more and more popular.
6. Comprehensive impact of chemical rubber additives on tire performance
The reasonable application of chemical rubber additives can not only significantly improve the basic performance of tires, but also bring the following comprehensive benefits:
Improve safety performance: enhance crack resistance and fatigue resistance;
Extend service life: improve aging resistance and heat resistance;
Improve driving experience: optimize elasticity and grip performance;
Energy saving and emission reduction: reduce rolling resistance and save fuel.
7. Future trends and challenges
1. Research and development of green and environmentally friendly chemical additives
New environmentally friendly additives will reduce the release of volatile organic compounds and meet the requirements of sustainable development.
2. Innovation of high-performance and multifunctional additives
Integrate chemical additives with multiple functions, simplify the formula, and improve production efficiency and product performance.
3. Intelligent and customized formula design
Combining big data and material science, realize the refined additive design for different tire application scenarios.
4. Dealing with raw material price fluctuations and supply chain risks
Additive supply stability and cost control have become important challenges for enterprises.
VIII. Summary
Chemical rubber additives play a key role in promoting vulcanization, improving aging resistance, enhancing mechanical properties and optimizing production processes in tire formulations. They are not only the basis for ensuring tire performance, but also an important driving force for promoting tire technology progress and product upgrades. With the continuous development of industry technology, green, environmentally friendly, multifunctional and efficient chemical additives will become an inevitable choice for tire manufacturing.
