Reasons for choosing our testing services
ZHONGXI Testing has obtained inspection qualification certifications from multiple countries and regions worldwide. We possess a senior testing team and advanced testing methods, providing independent, impartial, and professional third-party verification services for global carbon projects.
Internationally recognized authority
Certified by multiple international standards such as CNAS, VCS, and GS, with reports universally applicable worldwide.
Global service capability
Covering 140+ countries and regions, it supports on-site detection and remote verification in multiple languages.
Professional experimental methods
Adopt standard experimental methods to ensure accurate and reliable data.
For procurement and quality teams, a clear definition of testing scope significantly reduces communication time and ensures efficient service delivery. Our free radical scavenging testing services evaluate a material's ability to neutralize free radicals, a critical property for polymers, additives, and specialty chemicals exposed to oxidative environments. This capability is essential for industries requiring materials with enhanced durability, such as automotive, electronics, and packaging sectors. By understanding a material's radical scavenging efficiency, clients can predict performance degradation and optimize product lifespans.
Testing Scope
Our free radical scavenging testing covers a wide range of materials and applications. Applicable products include polymers (e.g., PE, PP, PVC, EPDM), plastics, rubber compounds, lubricants, coatings, and chemical additives. We support various grades, from industrial-grade to high-performance specialty chemicals, tailored to client specifications. Application scenarios typically involve environments prone to oxidative degradation, such as UV exposure, high temperatures, or contact with reactive compounds. Commonly referenced standards include ASTM D4722, ISO 11950, EN 12566, and GB/T 18443, ensuring alignment with global regulatory requirements.
Testing Items and Parameters
Testing items focus on evaluating the scavenging efficiency and kinetic behavior of free radicals. Typical parameters include:
| Test Item | Typical Parameters | Graded Limit Requirements |
|---|---|---|
| Radical Scavenging Efficiency | Initial scavenging rate (mM/s), half-life (min), total scavenged radicals (%) | Min. 85% efficiency for industrial grades; ≥95% for high-performance grades |
| Thermal Stability | Decay rate at 100°C, 150°C, 200°C (nm/min) | Max. 5% decay within 1 hour at 150°C |
| Stoichiometric Ratio | Active sites per molecule (mol/mol), residual activity after 10 cycles (%) | Min. 90% residual activity after 10 cycles |
| Compatibility with Matrix Materials | Influence on neighboring components (e.g., discoloration, leaching test) | No significant degradation or transfer to adjacent materials |
Additional parameters may be requested based on material composition and client needs. All results are graded against industry benchmarks and specific project requirements.
Data and Variation Analysis
Parallel-sample and batch-to-batch variation is rigorously assessed using statistical analysis. For parallel-sample consistency, relative deviation between replicate tests is calculated using the formula:
Relative Deviation (%) = [(Test Value Mean - Individual Test Value) / Test Value Mean] × 100
Tolerable limits are set at ±5% for industrial grades and ±3% for high-performance grades. Batch-to-batch variation is analyzed by comparing mean values across multiple production batches, with acceptance windows defined as follows:
• Industrial grades: Acceptance window = ±10% of target value
• High-performance grades: Acceptance window = ±7% of target value
Variation data is reported alongside mean values, standard deviations, and confidence intervals (95%). This ensures clients can validate material consistency and make informed decisions regarding quality control and procurement strategies.
To proceed, please confirm your required testing items and sample quantity. We will revert with a formal quotation and expected schedule tailored to your specific needs.