Composite antioxidant: Key technologies to improve the antioxidant properties of plastic products
In modern society, plastic products are everywhere. From the water bottles, food packaging we use every day to the shells of auto parts and electronic equipment, plastic has been deeply integrated into our lives. However, although plastics have the advantages of lightness and durability, their antioxidant properties often become an important factor restricting their service life. Over time, plastic products will turn yellow, become brittle and even crack due to oxidation, which not only affects the beauty, but may also bring safety hazards. To solve this problem, scientists have developed a key technology - composite antioxidants.
This article will conduct in-depth discussion on the mechanism of action, type classification, application fields of composite antioxidants and how to choose suitable composite antioxidants. At the same time, we will also comprehensively demonstrate the important role of composite antioxidants in improving the antioxidant properties of plastic products through specific case analysis and combined with domestic and foreign research literature. Whether you are an industry practitioner or an ordinary reader interested in materials science, this article will provide you with rich knowledge and practical guidance.
What are compound antioxidants?
Composite antioxidant is a chemical additive specially used to delay or inhibit the oxidation reaction of plastic products. They prevent the occurrence of free radical chain reactions by interacting with plastic molecules, thereby significantly improving the durability and stability of plastic products. Simply put, compound antioxidants are like putting on plastics a "protective suit" to make it stronger when facing the "enemy" of oxygen.
Basic Functions of Compound Antioxidants
The main functions of composite antioxidants can be summarized as follows:
- Catch free radicals: Oxidation reactions are usually chain reactions triggered by free radicals. Complex antioxidants can effectively capture these free radicals and terminate the reaction chain.
- Decomposition of peroxides: Peroxides are intermediates produced during oxidation, which will further accelerate the oxidation reaction. Complex antioxidants can decompose these peroxides and reduce their damage to plastic molecules.
- Prevent photooxidation: UV rays in sunlight will aggravate the oxidation process of plastics. Some components in composite antioxidants can absorb ultraviolet rays and protect plastics from photooxidation.
Through the above functions, composite antioxidants not only extend the service life of plastic products, but also maintain their original physical and chemical properties.
Next, we will discuss in detail the types of composite antioxidants and their respective characteristics.
Types and characteristics of composite antioxidants
Composite antioxidants can be divided into various types according to their chemical structure and mechanism of action. Each type of antioxidant has its own unique propertiesand scope of application, so in actual application, you need to choose according to specific needs. The following are several common composite antioxidants and their characteristics:
1. Primary Antioxidants
The main antioxidant inhibits the chain propagation of the oxidation reaction mainly by capturing free radicals. They are the basics and one of the important antioxidants categories.
Common types:
- Phenol antioxidants: such as BHT (butylated hydroxyl) and BHA (butylated hydroxyanisole). This type of antioxidant is widely used in food packaging and medical devices due to its efficient free radical capture capability.
- Amine antioxidants: For example, aromatic amine compounds have strong antioxidant properties, but may cause discoloration of plastics, so they are mostly used for industrial purposes rather than food contact materials.
| Type | Features | Application Fields |
|---|---|---|
| Phenol antioxidants | Efficiently capture free radicals, good safety | Food Packaging, Medical Devices |
| Amine antioxidants | Strong antioxidant capacity, but easy to cause discoloration | Industrial products, non-food contact materials |
2. Secondary Antioxidants
Auxiliary antioxidants are mainly used to decompose peroxides, thereby indirectly inhibiting oxidation reactions. They are usually used in conjunction with the main antioxidant for better results.
Common types:
- Phosophile antioxidants: For example, tris(nonylphenyl)phosphite can effectively decompose peroxides and prevent plastic aging.
- Thiodipropionate antioxidants: Such as bidodecylthiodipropionate, which has good thermal stability and antioxidant properties.
| Type | Features | Application Fields |
|---|---|---|
| Phosphite antioxidants | Decompose peroxides and have good thermal stability | Engineering Plastics, Films |
| Thiodipropionate antioxidants | Decompose peroxides and have strong antioxidant properties | Auto parts, cable materials |
3. Light Stabilizers
Light stabilizers are a special class of antioxidants, specially designed to prevent photooxidation reactions caused by ultraviolet rays. They protect plastics from photoaging by absorbing or reflecting ultraviolet rays.
Common types:
- Ultraviolet absorbers: Such as benzotriazole compounds, they can effectively absorb ultraviolet rays and prevent plastic from fading and becoming brittle.
- Free Radical Scavenger: Such as hindered amine light stabilizers, they can not only capture free radicals, but also decompose peroxides, and double-protect plastics.
| Type | Features | Application Fields |
|---|---|---|
| Ultraviolet absorber | Absorb UV rays to prevent photooxidation | Outdoor plastic products |
| Free Radical Scavenger | Double protection, capture free radicals and decompose peroxides | Auto housing, outdoor membrane |
4. Synergistic Antioxidants
Synergy antioxidants refer to compounds that have weak antioxidant capabilities but can significantly enhance the overall effect when used with other antioxidants. Their presence makes the composite antioxidant system more efficient.
Common types:
- Metal ion chelating agents: For example, EDTA (ethylenediamine titanium) can chelate metal ions and prevent them from catalyzing oxidation reactions.
- Wax substances: Such as microcrystalline wax, it can form a protective film on the surface of the plastic to reduce oxygen contact.
| Type | Features | Application Fields |
|---|---|---|
| Metal ion chelating agent | Prevent metal ion catalytic oxidation reaction | Medical devices, food packaging |
| Wax substances | Form a protective film to reduce oxygen contact | Agricultural mulching film and packaging materials |
From the above classification, it can be seen that different types of composite antioxidants have their own emphasis and are suitable for different application scenarios. In practical applications, it is often necessary to use a combination of multiple antioxidants to achieve an optimal antioxidant effect.
Mechanism of action of composite antioxidants
To understand why complex antioxidants are so important, we need to have a deeper understanding of their mechanism of action. The oxidation process of plastic products is a complex chemical reaction chain, mainly including the following stages: the initiation stage, the propagation stage and the termination stage. Complex antioxidants effectively delay or prevent the occurrence of oxidation reactions by intervening in these stages.
Initiation stage: The birth of free radicals
The starting point of the oxidation reaction is usually the formation of free radicals. When plastics are exposed to high temperatures, light or oxygen, their molecular chains may break and free radicals are created. These free radicals are like "flames" that once ignited, they will trigger a chain reaction.
The main antioxidant in the composite antioxidant plays a key role at this stage. They prevent further development of the reaction chain by providing hydrogen atoms or other reactive groups, rapidly capturing free radicals, converting them into stable compounds.
Propagation stage: diffusion of chain reaction
If the radicals are not captured in time, they will react with the surrounding plastic molecules to create new radicals. This chain reaction will continue to spread, eventually leading to large-scale degradation of plastic molecules.
At this time, auxiliary antioxidants appear. They prevent further spread of the oxidation process by decomposing peroxides and cutting off the reaction chain. This "fire extinguishing" effect is crucial to maintaining the integrity of plastics.
Termination phase: Restoration of stable state
Under the intervention of the composite antioxidant, the oxidation reaction gradually stopped and the plastic molecules re-entered the stable state. Synergistic antioxidants play an important role in this stage to ensure balance and durability of the entire system.
Through the intervention of the above three stages, the composite antioxidant successfully protects the plastic products from oxidation. This process can be described in a metaphor: Compound antioxidants are like a trained fire brigade ready to put out fires and protect the safety of buildings.
Application fields of composite antioxidants
The application areas of composite antioxidants are very wide, covering almost all industries involving plastic products. Below we will introduce the application situation in detail in several major areas.
1. Packaging Industry
In the packaging industry, composite antioxidants are mainly used in food packaging and beverage containers. Since these products are directly in contact with human food, they have extremely high safety requirements. Phenol antioxidants are the first choice for their low toxicity and high efficiency.
| Application Scenario | Types of antioxidants used | Main Function |
|---|---|---|
| Food Packaging | Phenol antioxidants | Improve the oxidation resistance of packaging materials |
| Beverage container | Ultraviolet absorber | Prevent photooxidation and maintain the taste of the beverage |
2. Automobile Industry
The automobile industry has extremely high requirements for the durability and stability of plastic products, especially in high temperature environments such as engine compartments. Amines and phosphite antioxidants are often used to make automotive parts to ensure that they do not age for long-term use.
| Application Scenario | Types of antioxidants used | Main Function |
|---|---|---|
| Engine cover | Amine antioxidants | Improving heat resistance and oxidation resistance |
| Car interior | Ultraviolet absorber | Prevent photoaging and maintain beautiful appearance |
3. Medical devices
Medical devices have extremely strict requirements on the safety and stability of materials. Metal ion chelating agents and phenolic antioxidants are often used to make medical devices to ensure that they do not release harmful substances during use.
| Application Scenario | Types of antioxidants used | Main Function |
|---|---|---|
| Syringe | Metal ion chelating agent | Prevent metal ion contamination |
| Infusion tube | Phenol antioxidants | Improve the biocompatibility of materials |
4. Agricultural field
In the agricultural field, agricultural mulching needs to have good weather resistance and anti-aging properties. UV absorbers and wax substances are often used to make agricultural mulch to ensure that they are used for a long time in outdoor environments without damage.
| Application Scenario | Types of antioxidants used | Main Function |
|---|---|---|
| Agricultural mulching | Ultraviolet absorber | Prevent photoaging and extend service life |
| Greenhouse Covering Materials | Wax substances | Reduce oxygen contact and improve durability |
From the above cases, it can be seen that the application of composite antioxidants in various fields has played an irreplaceable role. They not only improve the performance of plastic products, but also bring significant economic and social benefits to related industries.
How to choose the right compound antioxidant?
Selecting the right composite antioxidant is a critical step in ensuring the performance of plastic products. Here are some factors to consider when choosing a compound antioxidant:
1. Application environment
The requirements for composite antioxidants vary in different application environments. For example, outdoor plastic products need to focus on light stability, while food contact materials pay more attention to safety.
2. Cost Budget
The price difference between composite antioxidants is large, and the balance between cost and performance needs to be comprehensively considered when choosing. Generally speaking, high-performance antioxidants are more expensive, but in some cases, appropriately increasing investment can result in higher returns.
3. Processing technology
Different processing processes may affect the effectiveness of composite antioxidants. For example, during injection molding, high temperatures can cause some antioxidants to decompose and fail. Therefore, processing conditions need to be fully considered when selecting antioxidants.
4. Regulations Requirements
The regulations and requirements for plastic products in different countries are different. When choosing composite antioxidants, you need to ensure that they meet relevant standards. Compliance is particularly important in the fields of food contact materials and medical devices.
By taking into account the above factors, we can better select composite antioxidants suitable for specific application scenarios, thereby achieving an excellent antioxidant effect.
Conclusion
Composite antioxidants, as a key technology to improve the antioxidant properties of plastic products, have been widely used in all walks of life. They effectively delay the aging process of plastics and improve the service life and performance of the product by capturing free radicals, decomposing peroxides and preventing photooxidation.
In the future, with the continuous development of science and technology, the research on composite antioxidants will also be more in-depth. We look forward to seeing more new antioxidants appearing to bring greater benefits to the plastics industryinnovation and development opportunities. As one scientist said: "Composite antioxidants are not only the guardian of plastics, but also an important force in promoting the progress of materials science." Let us look forward to more exciting performances in this field together!
Extended reading:https://www.bdmaee.net/wp-content/uploads/2022/08/Polyurethane-rigid-foam-catalyst-CAS-15875-13-5-catalyst-PC41.pdf
Extended reading:https://www.newtopchem.com/archives/43932
Extended reading:https://www.newtopchem.com/archives/43088
Extended reading:https://www.newtopchem.com/archives/39602
Extended reading:https://www.bdmaee.net/u-cat-sa-831-catalyst-cas111-34-2-sanyo-japan/
Extended reading:https://www.bdmaee.net/dabco-xd-103-catalyst-cas10027-40-8-evonik-germany/
Extended reading:https://www.cyclohexylamine.net/teda-l33b-dabco-polycat-gel-catalyst/
Extended reading:https://www.bdmaee.net/wp-content/uploads/2021/05/138-1.jpg
Extended reading:https://www.cyclohexylamine.net/nnnnn-pentamethyldiethylenetriamine-pmdeta/
Extended reading:https://www.newtopchem.com/archives/1873
微信扫一扫打赏
