What’s POM acetal homopolymer?
POM acetal homopolymer stands for polyoxymethylene homopolymer. Compared to other variants of POM, homopolymers have a higher melting point and are 10-15% stronger than copolymers. However, both variants share the same shock characteristics. POM-H is produced by the anionic polymerization of formaldehyde with good crystallization and high stiffness and strength. Overall, POM-H has better physical and mechanical properties than POM-C. POM-H is best suited for applications requiring properties such as good wear resistance and a low coefficient of friction.
What’s POM acetal copolymers?
POM acetal copolymers stands for polyoxymethylene copolymer. This is produced by the cationic polymerization of trioxane. During this process, small amounts of comonomer are added to increase compactness while reducing crystallinity. However, the stiffness and strength of POM-C are lower than those of POM-H. However, its machinability is higher than that of POM-H. Because of this, POM-C is the most widely used POM (75% of total POM sales). POM-C is ideal for applications requiring properties such as a low coefficient of friction.
What is the difference between POM acetal homopolymer and POM acetal copolymer?
POM-H: The full name is POM acetal homopolymer. It is formed by anionic polymerization of formaldehyde. A typical example is DuPont’s Delrin®. And Cylex LLC can produced Delrin® 150.
POM-C: The full name is POM acetal copolymer. It’s formed by cationic polymerization of trioxane. Cylex LLC produced the high performance ratio POM acetal copolymer
Characteristics of POM-H and POM-C
Hardness and Stiffness
POM-H: POM-H is hard and hard
POM-C: POM-C is not as hard and stiff as POM-H.
Processability
POM-H: Low workability.
POM-C: High workability.
Melting Point
POM-H: Melting point is 172-184 °C.
POM-C: Melting point is 160-175 °C.
Processing Temperature
POM-H: The processing temperature of POM-H is 194-244°C.
POM-C: The processing temperature of POM-C is 172-205℃.
Elastic Modulus (MPa) (tensile at 0.2% water content)
POM-H: The elastic modulus is 4623.
POM-C: The modulus of elasticity is 3105.
Glass Transition Temperature (t g )
POM-H: Glass transition temperature is -85°C.
POM-C: The glass transition temperature is -60°C.
Tensile Strength
POM-H: The tensile strength is 70MPa.
POM-C: The tensile strength is 61MPa.
Elongation
POM-H: Elongation is 25%.
POM-C: Elongation is 40-75%.
Application
POM-H: Abrasive attachments for bearings, gears, conveyor belt links, seat belts and hand mixes are some examples of POM-H.
POM-C: Electric kettles, kettles, snap assemblies, chemical pumps, bathroom scales, telephone keypads, household enclosures, etc. are some of the applications of POM-C.
