what is polyoxymethylene made of

In this article, we will delve into the composition of polyoxymethylene (POM) – an engineering thermoplastic widely used in precision parts. We will explore what POM is made of, its material components, and its overall composition that gives it its unique properties.

Polyoxymethylene, also known as acetal, polyacetal, and polyformaldehyde, is produced by different chemical firms with slightly different formulas and sold under various names. Despite these variations, POM is characterized by its high strength, hardness, rigidity, and its intrinsic opaque white appearance. It can also be produced in a variety of colors, making it versatile for different applications.

POM finds its application in numerous industries, including automotive, consumer electronics, and manufacturing, where its properties are highly valued. It is used in the production of small gear wheels, eyeglass frames, ball bearings, ski bindings, fasteners, gun parts, knife handles, and lock systems. The dimensional stability and resistance to wear make POM an excellent choice for these high-performance components.

Join us as we dive into the details of polyoxymethylene and explore its properties, production processes, applications, advantages, and disadvantages. By the end of this article, you will have a comprehensive understanding of this remarkable engineering thermoplastic.

Properties of Polyoxymethylene

Polyoxymethylene (POM) is an engineering thermoplastic known for its remarkable properties and wide range of applications. Let’s explore the key characteristics that make POM a sought-after material in various industries.

High Density and Melting Point

Polyoxymethylene has a density ranging from 1.410 to 1.420 g/cm3. This high density contributes to its exceptional strength and rigidity. Additionally, POM has a melting point of 165°C, allowing it to retain its structural integrity even in demanding environments.

Excellent Strength and Hardness

One of the defining features of POM is its remarkable strength and hardness. These properties make it ideal for applications that require components to withstand heavy loads and constant wear. Whether it’s small gear wheels, lock systems, or knife handles, POM provides the durability and reliability needed for demanding tasks.

Stability in Various Temperatures

Polyoxymethylene exhibits excellent stability even at low temperatures, making it suitable for applications in extreme environments. Whether it’s exposed to freezing temperatures or high heat, POM maintains its structural integrity, ensuring the smooth operation of critical components.

Dielectric Properties

POM possesses impressive dielectric properties, including an electrical resistivity of 14×1015 Ω⋅cm and a breakdown voltage of 19.5MV/m. These characteristics enable POM to function as an effective insulator, making it valuable in applications that require electrical insulation and protection.

Opague White Appearance

Due to its high crystalline composition, POM has an opaque white appearance. This aesthetically pleasing feature, coupled with its excellent performance properties, makes POM a popular choice in industries where both functionality and visual appeal are essential.

Synthesis Process

The synthesis of polyoxymethylene involves the reaction of formaldehyde with an alcohol to create a hemiformal. This intermediate compound is then polymerized and stabilized to form the final POM material. The precise synthesis process may vary depending on the specific requirements and desired properties of the POM product.

polyoxymethylene synthesis

In summary, polyoxymethylene offers a unique combination of density, strength, hardness, stability, and dielectric properties. These qualities, coupled with its opaque white appearance, are the key factors driving its widespread use in industries ranging from automotive to consumer electronics.

Production of Polyoxymethylene

Polyoxymethylene is manufactured through different processes depending on whether it is a homopolymer or copolymer. Let’s explore the production methods for each.

Homopolymer Production

For homopolymer polyoxymethylene production, the process begins by generating anhydrous formaldehyde. This is achieved by reacting aqueous formaldehyde with an alcohol to create a hemiformal. The hemiformal is then dehydrated and heated, releasing formaldehyde. The formaldehyde goes through polymerization and stabilization to ultimately create the homopolymer.

Copolymer Production

Copolymer polyoxymethylene involves replacing a portion of the −CH2O− groups with −CH2CH2O−. This process starts with the conversion of formaldehyde to trioxane. A co-monomer such as dioxolane or ethylene oxide is added to the trioxane. Polymerization is then carried out using an acid catalyst. The resulting copolymer is stabilized and melted for further processing.

polyoxymethylene production process

The image above illustrates the production process of polyoxymethylene. It showcases the steps involved in both homopolymer and copolymer production, highlighting the raw materials and key reactions.

Production Process Raw Materials Key Reactions
Homopolymer Aqueous formaldehyde, alcohol Dehydration, polymerization, stabilization
Copolymer Formaldehyde, trioxane, co-monomer (e.g., dioxolane or ethylene oxide) Conversion of formaldehyde, addition of co-monomer, polymerization, stabilization

The table above summarizes the raw materials and key reactions involved in the production of polyoxymethylene. It provides a concise overview of the different processes used to manufacture both homopolymer and copolymer variants.

Applications of Polyoxymethylene

Polyoxymethylene (POM) is a versatile material that finds applications in a wide range of industries due to its exceptional properties such as high strength and dimensional stability. Let’s explore some of the key uses of POM:

1. Automotive Industry

In the automotive industry, POM is extensively used for manufacturing high-performance engineering components. It is commonly employed in the production of gear wheels, ski bindings, fasteners, and lock systems. The strong and rigid nature of POM makes it ideal for applications that require high mechanical strength and durability.

2. Consumer Electronics

POM is also widely utilized in the consumer electronics sector. It is employed in the production of eyeglass frames, ball bearings, and various precision parts. The excellent dimensional stability of POM ensures the longevity and reliability of these electronic components.

3. Industrial Equipment

Industrial equipment often requires materials that can withstand demanding conditions and provide low friction. POM fulfills these requirements, making it a preferred choice for manufacturing gun parts, knife handles, and other precision parts in industries such as manufacturing, construction, and machinery.

uses of polyoxymethylene

4. Other Applications

Besides the industries mentioned above, POM also finds applications in numerous other sectors. Some examples include electrical connectors, plumbing fittings, and furniture components. Its high stiffness, wear resistance, and dimensional stability make it suitable for various demanding applications.

Industry Applications
Automotive Gear wheels, ski bindings, fasteners, lock systems
Consumer Electronics Eyeglass frames, ball bearings, precision parts
Industrial Equipment Gun parts, knife handles, precision parts
Other Electrical connectors, plumbing fittings, furniture components

In summary, polyoxymethylene (POM) is widely utilized in numerous industries for its exceptional properties. From automotive components to consumer electronics and industrial equipment, POM’s high strength, dimensional stability, and resistance to wear make it an ideal material for a wide range of applications.

Advantages and Disadvantages of Polyoxymethylene

Polyoxymethylene (POM) offers a range of advantages that make it a popular choice in various industries. Its high strength, hardness, and rigidity make it suitable for applications that require robust and durable materials. POM also exhibits excellent dimensional stability, meaning that it maintains its shape and size even under varying conditions.

Another key advantage of POM is its ability to withstand low temperatures without compromising its mechanical properties. This makes it ideal for applications in environments where temperature fluctuations are common, such as automotive components or outdoor equipment.

POM’s resistance to wear is another notable advantage. It has a low coefficient of friction against steel, making it suitable for applications that involve sliding or rotating movements. This property allows POM to be used as a replacement for metal parts while maintaining comparable strength.

Despite its advantages, POM does have some limitations to consider. One potential drawback is its potential to produce formaldehyde, which can be objectionable in certain applications. Moreover, POM is known to be difficult to bond, limiting its adhesive properties. It also has a lower thermal stability compared to some other engineering plastics, which may restrict its use in high-temperature environments.

Advantages and Disadvantages of Polyoxymethylene

Advantages of Polyoxymethylene:

  • High strength, hardness, and rigidity
  • Excellent dimensional stability
  • Resistance to wear
  • Low coefficient of friction against steel

Disadvantages of Polyoxymethylene:

  • Potential formaldehyde production
  • Difficult to bond
  • Limited adhesive properties
  • Lower thermal stability compared to some other engineering plastics


In conclusion, polyoxymethylene (POM) is an engineering thermoplastic that is composed of various chemical compounds produced by different manufacturers. POM material components are known for their high strength, hardness, and rigidity, making them suitable for precision parts in a wide range of industries. This versatile material offers excellent dimensional stability and resistance to wear, making it ideal for high-performance applications.

Polyoxymethylene manufacturing ingredients result in the material’s opaque white appearance, but it can also be produced in different colors to suit specific requirements. Despite its advantages, it is important to consider some limitations of this material. Formaldehyde production is a potential concern, and bonding POM can be challenging due to its limited adhesive properties. Additionally, its thermal stability is relatively lower compared to certain other engineering plastics. Despite these drawbacks, the composition of polyoxymethylene makes it a valuable and sought-after material in engineering and manufacturing.

With its excellent mechanical properties and versatility, polyoxymethylene continues to be a preferred choice for applications that require durability, dimensional stability, and high-performance performance. From automotive components to consumer electronics and precision parts, POM has proven its reliability and functionality. As manufacturers continue to innovate and refine the production process, the future looks promising for this robust engineering thermoplastic.


What is polyoxymethylene made of?

Polyoxymethylene, also known as POM or acetal, is composed of different chemical compounds produced by various manufacturers. It is typically made from the polymerization of formaldehyde or trioxane, along with the addition of co-monomers such as dioxolane or ethylene oxide.

What are the components of POM material?

The main components of polyoxymethylene are formaldehyde or trioxane, which are polymerized to form the polymer chains. Co-monomers such as dioxolane or ethylene oxide may also be added to modify the properties of the material.

How is polyoxymethylene synthesized?

Polyoxymethylene is synthesized through a process called polymerization. Anhydrous formaldehyde or trioxane is generated by reacting aqueous formaldehyde with an alcohol to create a hemiformal, followed by dehydration and heating. The formaldehyde or trioxane is then polymerized and stabilized to form the final polyoxymethylene material.

What is the production process of polyoxymethylene?

The production process of polyoxymethylene depends on whether it is a homopolymer or a copolymer. For the homopolymer version, anhydrous formaldehyde is generated, polymerized, and stabilized. Copolymer versions involve the addition of co-monomers, such as dioxolane or ethylene oxide, during the polymerization process to create the desired properties.

What are the common applications of polyoxymethylene?

Polyoxymethylene is widely used in various industries for applications that require high strength and dimensional stability. It is commonly used in automotive components like gear wheels, ski bindings, and fasteners. It is also utilized in consumer electronics for eyeglass frames and ball bearings. Additionally, POM is used in the production of gun parts, knife handles, and precision parts that require low friction.

What are the advantages of polyoxymethylene?

Polyoxymethylene offers several advantages, including high strength, hardness, and rigidity. It has excellent dimensional stability and can withstand low temperatures. POM is resistant to wear and has a low coefficient of friction against steel. It is also a lightweight alternative to metals while offering comparable strength.

What are the disadvantages of polyoxymethylene?

While polyoxymethylene has many advantages, it does have some limitations. POM can produce formaldehyde, which may be objectionable in certain applications. Additionally, it is difficult to bond and has limited adhesive properties. POM also has a lower thermal stability compared to some other engineering plastics.

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