Aging reasons of TPE / TPR products and measures to improve anti - aging performance
TPE / TPR materials are based on SEBS / SBS modified thermoplastic elastomer material. Some outdoor use of TPE / TPR products, by the long-term effects of radiation, ozone, ultraviolet light, etc. may be aging, making the TPE.TPR material quickly lost Its performance.Therefore, for this type of TPE / TPR products, need to improve its anti-aging properties.
Aging concept: Polymer materials in the process of processing, storage and use, due to the combined effect of internal and external factors, its performance deteriorates, resulting in the loss of value of the phenomenon. Aging is an irreversible change, it is a common problem of polymer materials. However, people can adopt the appropriate anti-aging measures to improve the anti-aging properties of materials by delaying the aging process of polymers and delaying the aging rate so as to prolong the service life.
Aging reasons: due to the structure or components within the aging prone to have weaknesses, such as having an unsaturated double bond, peroxide, branching, carbonyl, terminal hydroxyl, and so on. External or environmental factors are mainly sunlight, oxygen, ozone, heat, water, mechanical stress, high-energy radiation, electricity, industrial gases such as carbon dioxide, hydrogen sulfide, seawater, salt spray, mold, bacteria, insects and the like.
The nature of aging: groups with poor chemical stability (low chemical bond) at the micro-scale of the polymer chain are subject to irreversible changes in the structure of the material due to the long-term effects of stronger oxidizing (higher chemical bond) materials from the outside world.
TPE / TPR material aging resistance and improve the mechanism: SEBS chemical bond saturation, SBS (containing unsaturated carbon-carbon double bond) has better chemical stability, accordingly, SEBS-based TPE SBS-based TPR has better Anti-aging performance. Although SEBS has good anti-aging properties, long-term exposure to or action on more oxidizing media such as ozone and UV rays can destroy the material structure of SEBS and cause deterioration and deterioration of the material. Anti-aging requirements of the TPE, TPR products, need to add functional additives such as antioxidants. TPE compounding system by adding antioxidants, effectively prevent or delay the strong oxidative media outside the material anti-aging effect, thus protecting the SEBS material aging.
Generally, TPE materials based on SEBS can achieve anti-aging anti-UV performance up to grade 3.5. For TPE / TPR materials with higher anti-aging requirements, antioxidants need to be added for improvement.