Frequently asked questions
You will find below the answers to the questions we are asked the most about antioxidants and light stabilisers
What are antioxidants and how do they protect materials?
Antioxidants are substances that protect materials from damage caused by various processes, particularly oxidation. Oxidation is a chemical process in which substances, especially organic compounds, react with oxygen from the air, which is a common form of material damage.
Antioxidants can be categorised into two main types: primary antioxidants and secondary antioxidants:
- Primary antioxidants, such as phenolic- and aminic antioxidants, play a crucial role in preventing oxidation by directly inhibiting the oxidation process. They intercept and neutralise free radicals before they can cause harm.
- Secondary antioxidants, including phosphites and thioesters, work alongside primary antioxidants to provide an additional layer of protection. They complement the action of primary antioxidants by enhancing their effectiveness and scavenging hydroperoxides, chemicals generally formed by the reaction of oxygen with certain organic compounds.
By working together, primary and secondary antioxidants form a comprehensive defence system against harmful reactions, safeguarding materials and extending their lifespan. This combination ensures a more robust and effective protection against autoxidation and other damaging processes.
How are antioxidants produced?
Various chemical reactions are employed in the production of different types of antioxidants.
One type, known as phenolic antioxidants, is created when specially designed molecules, called sterically hindered phenols, are complemented with specific substituents.
Another type of antioxidants, called thioesters, is made by reacting specific organic acids known as thiocarboxylic acids with alcohols.
Lastly, phosphites are produced by combining phosphorus halides with alcohols and specific kinds of phenols, known as alkylated phenols.
How do antioxidants work?
Antioxidants are indispensable for maintaining the integrity and longevity of plastic products and other materials. They function by disrupting damaging radical chain reactions and slowing down the process of autoxidation. This process involves the reaction of oxygen from air with the polymers used in plastics, which can ultimately lead to the degradation of the material over time.
Various types of antioxidants serve specific purposes in this preservation process. Phenolic- and aminic antioxidants, for instance, effectively intervene in radical chain reactions along the polymer backbone, thereby retarding autoxidation. This action prevents the breakdown or scission of polymer chains, which helps maintain the mechanical properties of the plastic articles throughout their lifetime.
Moreover, antioxidants like phosphites and thioesters play crucial roles. Phosphites are particularly beneficial during polymer processing stages into plastic articles, shielding the material from degradation, while thioesters safeguard the polymer throughout its entire lifespan.
By incorporating these antioxidants into plastic products and other materials, we can enhance their durability and resistance to degradation, ensuring that the articles retain their desired characteristics for an extended period, therefore contributing to a more sustainable use.
What are light stabilisers and how do they protect materials?
UV light stabilisers are crucial additives used to safeguard materials from the harmful effects of ultraviolet (UV) radiation. They play a vital role in industries such as plastics, coatings and textiles. Here are two main types of UV light stabilisers commonly used:
- UV Absorbers: UV absorbers act as a shield, preventing UV light from reaching the sensitive components of the material and preserving its integrity. They function by absorbing UV radiation and converting it into heat, thereby preventing it from causing damage to the material. Several types of UV absorbers are commonly used, including benzophenones, benzotriazoles, hydroxybenzoates, oxanilides and triazines. These additives are designed to effectively absorb specific wavelengths of UV light, offering protection to the material in which they are incorporated.
- Hindered Amine Light Stabilisers (HALS): HALS are a class of light stabilisers that work by scavenging and neutralising free radicals generated by UV radiation. Free radicals can initiate degradation reactions in materials exposed to UV light, in a process called photo-oxidation, leading to colour fading, chalking and loss of mechanical properties. HALS inhibit these degradation reactions and help preserve the material’s integrity. They are particularly effective in polymers and coatings, providing long-term UV protection.
Incorporating UV absorbers and HALS into products can significantly extend the lifespan of materials as well as maintain their aesthetic and functional properties when exposed to UV light. These light stabilisers contribute to the overall durability and performance over time, hence to a more sustainable use.
Do antioxidants and light stabilisers affect human health or the environment?
The safety of our substances throughout the entire value chain is of utmost importance for us, being during the manufacturing process, the handling by our Downstream Users to produce finished articles, or the use of consumers. All our products go through a thorough registration or approval processes by authorities on a worldwide basis. Since the early 1980s, all our products had to undergo examination regimes by authorities by providing specific data with respect to worker, environment and consumer safety.
ELiSANA was created with the mission to become a trusted reference on health, safety and environmental information related to antioxidants and UV light stabilisers. Toxicological experts from our member companies work closely together with responsible authorities on various scientific projects including toxicological and ecotoxicological studies to broaden the knowledge, in order to improve the safety assessment of our products.
Are antioxidants and light stabilisers sustainable?
By protecting plastics and other materials from damage by external influences, antioxidants and light stabilisers help safeguard materials and increase their lifespan, reducing the need for repair and replacement. Thereby, they contribute to a more sustainable use.