Polycarbonate (PC) is a thermoplastic polymer characterized by its strength, toughness, and optical transparency in specific grades. It is widely used across various industries due to its unique properties, including high impact resistance, thermal stability, and dimensional stability. Polycarbonate is synthesized primarily through bisphenol A (BPA) reaction with phosgene, resulting in a material that can be easily worked, molded, and thermoformed. Its versatility makes it suitable for various applications, from consumer products like eyewear and electronics to industrial uses such as automotive parts and aerospace components.
PC GRADES
GRADE | PRODUCER | MFR | DENSITY | DATASHEET |
---|---|---|---|---|
0407 UR | KHOZESTAN | 4/1-7/0 | 1/2 | download |
0710UR | KHOZESTAN | 7/1-10 | 1/2 | download |
1012 LED 3 | KHOZESTAN | 10/1-12 | 1/2 | download |
1012 S1 | KHOZESTAN | 10/1-12 | 1/2 | download |
1012 UR | KHOZESTAN | 10/1-12 | 1/2 | download |
1215 UR | KHOZESTAN | 12/1-15 | 1/2 | download |
1518 UR | KHOZESTAN | 15/1-18 | 1/2 | download |
1822 UR | KHOZESTAN | 18/1-22 | 1/2 | download |
ABS | KHOZESTAN | 20 | 1.13 | download |
CREAM | KHOZESTAN | 10 | 1.2 | download |
GF25 | KHOZESTAN | 8 | 1.4 | download |
W1 | LALEH | 10 | 1.2 | download |
What is Polycarbonate?
It is a highly versatile thermoplastic polymer, but what truly sets it apart is its exceptional strength, transparency, and impact resistance. Its unique combination of properties has revolutionized countless industries, from automotive to electronics. Imagine a material that can withstand significant impact without shattering, maintain its clarity even in harsh environments, and be molded into intricate shapes—that’s the power of polycarbonate.
Density | 1.20–1.22 g/cm³ |
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Refractive index | 1.584–1.586 |
Tensile strength | Column 2 Value 2 |
Glass transition temperature | 147°C (297°F) |
Chemical resistance to acids | Poor |
Gas permeation (Oxygen) | 70–130 cm³·mm/(m²·day·Bar) |
Properties of Polycarbonate
- Transparency
It is highly transparent and capable of transmitting over 90% of light, making it an excellent alternative to glass for various applications.
- Impact Resistance
It is virtually unbreakable and has high impact strength, which makes it resistant to fracture and suitable for safety applications.
- Mechanical Properties
Tensile Strength | 55-75 MPa (8,000-10,900 psi) |
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Flexural Strength | 120-140 MPa (17,400-20,300 psi) |
Impact Strength (Notched Izod) | 30-100 J/m (2.8-9.3 ft-lb/in) |
Elongation at Break | 50-150% |
Hardness (Shore D Scale) | 120-130 |
Density | 1.2 g/cm³ (0.043 lb/in³) |
- Thermal Properties
Thermal Conductivity | 0.15-0.22 W/(m·K) (0.027-0.04 BTU/(ft·h·°F)) |
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Specific Heat Capacity | 1.2 kJ/kg·K (0.29 BTU/lb·°F) |
Glass Transition Temperature | 147°C (297°F) |
Melting Point | 18 – 26 MV/m |
340°C (644°F) | 1 x 10^15 Ω |
- Electrical Properties
Dielectric Constant (at 1 kHz) | 2.9 – 3.4 |
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Dissipation Factor (at 1 kHz) | 0.004 – 0.006 |
Volume Resistivity (at 23°C) | 1 x 10^16 Ω·cm |
Dielectric Strength | 18 – 26 MV/m |
Surface Resistivity (dry) | 1 x 10^15 Ω |
Surface Resistivity (wet) | 1 x 10^9 Ω |
- Chemical Properties
Chemical Resistance | Excellent resistance to many chemicals, including acids, bases, and alcohols |
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Flammability | Self-extinguishing; meets UL94 V-0 rating |
Decomposition Temperature | 350°C (662°F) |
Applications of Polycarbonate
Automotive and Transportation
- Lighting and Lenses: These are used in headlamp lenses and light housings due to their transparency and heat resistance.
- Interior and Exterior Parts: PC blends are used for dashboards, bumpers, and other body parts because they are rigid and impact resistant.
Building and Construction
- Glazing: Polycarbonate is an alternative to glass in windows, skylights, and facades due to its high impact strength and UV resistance.
- Greenhouses: Its insulating properties make it ideal for creating optimal microclimates in greenhouses.
Medical
- Surgical Instruments and Devices: PCs are used in medical applications for their clarity, heat resistance, and sterilizability.
- Blood Filters and Reservoirs: Its transparency and toughness make it suitable for critical medical components.
Consumer Products
- Optical Media: Used in producing CDs and DVDs due to its low birefringence and high dimensional accuracy.
- Safety Equipment: Employed in safety goggles, face shields, and bullet-proof windows for their high impact resistance and optical clarity.
Electrical and Electronics
- Components: Used in various electrical components, including connectors, battery boxes, and lighting fixtures, due to its excellent electrical insulation properties.
Food Contact
- Containers: Polycarbonate is used in food storage containers because it is heat resistant and shatterproof, making it suitable for refrigerators and microwaves.
Production Process
The primary production process for polycarbonate is through the condensation polymerization reaction between bisphenol A (BPA) and phosgene. Here are the critical details about the polycarbonate manufacturing process:
Interfacial Polymerization Process
The most common and traditional method for producing polycarbonate is the interfacial polymerization process, which involves the following steps:
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- Bisphenol A is converted to its sodium salt (disodium bisphenol) by reacting it with sodium hydroxide in an aqueous solution.
- The disodium bisphenolate solution reacts with phosgene dissolved in an organic solvent like methylene chloride.
- This interfacial reaction between the two immiscible phases produces polycarbonate polymer chains and sodium chloride as a by-product.
- The polycarbonate is then precipitated, washed, and dried to obtain the final product.
While effective, this process has drawbacks like the use of toxic phosgene and the generation of large amounts of wastewater containing methylene chloride.
Non-Phosgene Melt Process
To address the environmental concerns, a non-phosgene melt process has been developed, which involves the following steps:
- Bisphenol A is reacted with diphenyl carbonate (DPC) instead of phosgene in a molten state at high temperatures (around 300°C).
- This transesterification reaction produces polycarbonate and phenol as a by-product.
- The phenol is removed under vacuum, and the polycarbonate is extruded into pellets or sheets.
The melt process is more environmentally friendly, has lower production costs, and eliminates the need for solvents and phosgene. In summary, while the traditional interfacial polymerization process using phosgene is still widely used, the non-phosgene melt process is gaining popularity due to its environmental and economic advantages.
Advantages & Disadvantages
Advantages
- Fire Resistance is fire-resistant and self-extinguishing, making it suitable for applications requiring high safety standards.
- Lightweight: It is twice as light as standard glass, which makes it easier to handle and install.
- Ease of Processing: it can be easily machined, drilled, bent, and polished, similar to acrylic sheets, but with greater strength and lower risk of breakage.
Disadvantages
- Scratch Sensitivity: it is prone to scratching, although this can be mitigated through polishing. Ensure you are fully informed about its potential challenges.
- Chemical Sensitivity: It has limited resistance to many chemicals, which can restrict its use in specific environments. For example, polycarbonate may not be suitable for use in environments with high concentrations of solvents or strong acids. However, it can still be used in many other environments, such as those with mild cleaning agents or water-based solutions.
POLY CARBONATE alternative
Alternatives are depending on the specific application. Here are some of the alternatives to polycarbonate:
1. Acrylic (PMMA)
This is a clear plastic with good impact resistance and weatherability. It is often used for signs, displays, and lenses. Acrylic is lighter than polycarbonate but can be more scratchable.
2. Triacetate (TAC)
This type of cellulose ester is clear, impact-resistant, and UV-resistant. It is often used for making eyeglasses and windshields for motorcycles and some convertibles. Triacetate is not as strong as polycarbonate and can degrade over time.
3. PETG (Polyethylene terephthalate glycol)
This is a glycol-modified version of PET (polyethylene terephthalate) known for its toughness and chemical resistance. It is often used for food packaging, water bottles, and thermoformed parts. PETG is not as clear as polycarbonate but can be more easily recycled.
This is a type of polystyrene that is modified to be more impact-resistant. It is often used for disposable cups, lids, and trays. HIPS is not as clear or strong as polycarbonate and is not UV-resistant.
5. Glass
While not plastic, glass is a viable alternative to polycarbonate in some applications where clarity and heat resistance are essential. Glass is more robust and scratch-resistant than polycarbonate. Still, it is also heavier and more brittle.
Conclusion
Polycarbonate (PC) is a superstar plastic prized for its exceptional clarity, impact resistance, and heat tolerance. This versatile material finds use everywhere, from bulletproof windows and medical devices to greenhouses and cellphone cases. Despite its strength, the PC can be easily molded and worked, making it a favorite for manufacturing. However, its production traditionally involves a toxic chemical, and scientists are actively developing more eco-friendly alternatives.