Polymat PBT
Polybutylene Terephthalate (PBT) is an High performance engineering thermoplastic known for its durability and versatility. Chemically, it is a polymer of butylene glycol and terephthalic acid. PBT combines good mechanical strength, with a tensile strength and excellent impact resistance. It maintains its performance within a temperature range up to 120°C (248°F) and has moderate thermal stability and low thermal expansion. PBT is highly resistant to many chemicals, including acids, bases, and organic solvents. Its applications span various industries, including automotive (electrical connectors and fuel system components), electronics (insulators and housings), medical (device components and prosthetics), and industrial manufacturing (bearings and gears). Its combination of properties makes it suitable for demanding environments and applications.
Mechanical Properties
- Tensile Strength: PBT typically has a tensile strength in the range of 50 to 70 MPa (megapascals). This measures its ability to withstand pulling forces.
- Flexural Strength: The flexural strength of PBT usually falls between 80 and 100 MPa. This property indicates how well it can resist deformation under bending stress.
- Impact Strength: PBT has good impact resistance, with impact strengths often around 1 to 2 kJ/m². This makes it suitable for applications where impact resistance is important.
- Modulus of Elasticity: The modulus of elasticity (or Young's modulus) for PBT is around 2.5 to 3.5 GPa (gigapascals). This measures the material’s stiffness or resistance to elastic deformation.
- Hardness: PBT has a Rockwell hardness typically in the range of R90 to R120, depending on its specific formulation and processing.
Thermal Properties
- Continuous Service Temperature: Typically up to 120°C (248°F), providing stability in moderate to high-temperature environments.
- Thermal Stability: Resists degradation in temperatures up to its melting point, making it suitable for various thermal conditions.
- Thermal Expansion: Exhibits moderate thermal expansion, which should be considered in precision applications.
- Glass Transition Temperature: Around 50°C (122°F), above which the material becomes more flexible and less rigid.
- Thermal Insulation Properties: Provides reasonable insulation against heat, useful in managing thermal conditions.
- Thermal Oxidative Stability: Performs adequately in moderate temperature oxidative environments, although not as high as some advanced materials.
Chemical Properties
- Acids: PBT generally has good resistance to weak acids, such as acetic acid and citric acid. However, its resistance to strong acids, like sulfuric acid or hydrochloric acid, is limited. Prolonged exposure to strong acids can degrade the material.
- Bases: PBT shows reasonable resistance to dilute bases, such as sodium hydroxide. It is less resistant to strong alkaline solutions, which can lead to hydrolysis and weakening of the material over time.
- Solvents: PBT has moderate resistance to a range of organic solvents, including alcohols and esters. However, it can be affected by hydrocarbons (such as gasoline and oils), which may cause swelling or degradation.
- Oils and Greases: PBT generally performs well against oils and greases, showing good resistance and minimal swelling or degradation.
- Water: PBT is relatively resistant to water absorption, but prolonged exposure to water, especially at elevated temperatures, can lead to hydrolytic degradation over time.
- Other Chemicals: PBT is also resistant to many weak and some strong chemicals. However, it’s always a good idea to test PBT with the specific chemicals it will encounter in its intended application to ensure compatibility.
Application Sectors
Aerospace
Used in components such as cable insulations, connectors, and structural parts due to its good mechanical strength, moderate thermal stability, and resistance to environmental factors.
Automotive
Employed in parts like electrical connectors, interior components, and fuel system parts. PBT offers good mechanical performance and resistance to automotive fluids and temperatures.
Medical
Utilized in applications such as medical device housings and components, thanks to its biocompatibility and ability to withstand sterilization processes.
Chemical Processing
Applied in various components such as fittings and valves where moderate chemical resistance and thermal stability are required.
Oil and Gas
Used in components such as seals and gaskets due to its chemical resistance and durability under moderate environmental conditions.
Electronics and Electrical
Ideal for electrical insulations, connectors, and housings due to its good electrical insulating properties and moderate thermal stability.
Industrial Manufacturing
Employed in parts like bearings, gears, and wear pads. PBT’s wear resistance and low friction characteristics make it suitable for many industrial applications.
Defense and Military
Used in applications such as protective equipment and structural components, providing good impact resistance and moderate thermal stability.
Semiconductors
Applied in semiconductor equipment where moderate thermal and chemical stability is required for various components.
Food and Beverage
Suitable for processing and packaging machinery components where compliance with food safety standards and resistance to cleaning agents are important.
Energy
Utilized in renewable energy applications such as wind turbine components due to its durability and resistance to environmental factors.
Textile and Apparel
Used in specialized fibers and fabrics where durability and resistance to wear are essential.