Basic Performance of PMMA

PMMA (Polymethyl methacrylate), as an important polymer material, possesses unique fundamental properties. The following is a detailed introduction from aspects such as optics, mechanics, thermology, chemistry, electricity, and processing performance:

Optical performance

High transparency: PMMA has an extremely high light transmittance, usually reaching over 92%, similar to optical glass, allowing light to pass through clearly and presenting objects with true colors and details. It is widely used in fields with high transparency requirements, such as optical lenses and transparent containers.

Low haze: Its haze is relatively low, and the light scattering when passing through PMMA material is less, which can ensure the clarity and sharpness of the image. It has important application value in optical instruments, display screens and other fields.

Ultraviolet light transmittance: PMMA has good transmittance to ultraviolet light within a certain wavelength range, which makes it applicable in some situations that require ultraviolet light irradiation, such as ultraviolet curing and plant growth lamps.

Mechanical properties

High strength: PMMA has certain tensile strength and bending strength, and can withstand certain external forces without being damaged. Its tensile strength is generally around 50 to 70MPa, and its bending strength is around 90 to 130MPa. It is suitable for making some components that need to withstand certain loads.

Moderate hardness: PMMA has a moderate hardness, which not only provides a certain degree of wear resistance but also facilitates processing and molding. Its Rockwell hardness (on the M scale) is approximately between 80 and 100, which can meet general usage requirements.

Poor toughness: However, PMMA has relatively poor toughness and is a brittle material. It is prone to brittle fracture when subjected to impact loads. Therefore, during the usage process, it is necessary to pay attention to avoiding excessive impact force.

Thermal performance

Glass transition temperature: The glass transition temperature (Tg) of PMMA is approximately 105℃. When the temperature is lower than Tg, the material is in a glassy state and has high hardness and strength. When the temperature is higher than Tg, the material enters a highly elastic state, becoming soft and elastic.

Heat distortion temperature: Its heat distortion temperature is relatively low, generally ranging from 70 to 100℃. This means that PMMA products are prone to deformation at higher temperatures, which limits their application in high-temperature environments.

Thermal stability: PMMA is prone to thermal decomposition at high temperatures, releasing monomers and other small-molecule substances, which leads to a decline in material performance. Therefore, during the processing and usage, the temperature needs to be controlled to prevent the material from overheating.

Chemical properties

Chemical resistance: PMMA has good resistance to many chemical substances, such as dilute acids, dilute alkalis, salt solutions, etc. However, in some organic solvents, such as acetone, chloroform, benzene, etc., it will dissolve or swell. Therefore, during use, it is necessary to avoid contact with these organic solvents.

Weather resistance: PMMA has good weather resistance and can be used outdoors for a long time without significant performance changes. It has a certain resistance to ultraviolet rays, ozone, etc., but long-term exposure outdoors may still cause the material surface to turn yellow and age.

Electrical performance

Insulation performance: PMMA is an excellent electrical insulating material with high volume resistivity and surface resistivity, which can effectively prevent the passage of current and is suitable for making electrical insulating components.

Dielectric properties: It has a relatively low dielectric constant and dielectric loss, and can still maintain good electrical properties under high-frequency electric fields. It can be used as a high-frequency insulating material in the fields of electronics, electrical appliances, etc.

Processing performance

Good formability: PMMA can be processed by various molding methods, such as injection molding, extrusion, blow molding, thermoforming, etc., and can produce products of various shapes and sizes.

Strong processability: It is easy to undergo mechanical processing, such as cutting, drilling, engraving, etc., and can meet the processing requirements of different products. In addition, PMMA can also undergo surface treatments such as bonding and coating to enhance its performance and appearance quality.