Polycarbonate vs. Polyethylene Terephthalate

Attribute	Polycarbonate	Polyethylene Terephthalate
Chemical Structure	Linear carbonate groups	Repeating ester units
Transparency	Clear and transparent	Transparent
Strength	High impact resistance	High tensile strength
Applications	Used in eyeglass lenses, CDs, and medical devices	Commonly used in plastic bottles, clothing fibers, and food packaging

Introduction

Polycarbonate and Polyethylene Terephthalate (PET) are two commonly used thermoplastic polymers that have a wide range of applications in various industries. While both materials have their own unique properties and characteristics, they also share some similarities. In this article, we will compare the attributes of Polycarbonate and Polyethylene Terephthalate to help you understand the differences between these two materials.

Physical Properties

Polycarbonate is a transparent, amorphous thermoplastic that is known for its high impact resistance and excellent clarity. It is also lightweight and has a high heat resistance, making it suitable for use in applications where durability and transparency are important. On the other hand, Polyethylene Terephthalate is a semi-crystalline thermoplastic that is known for its high tensile strength and excellent chemical resistance. It is also lightweight and has a low moisture absorption rate, making it suitable for use in applications where strength and chemical resistance are important.

Mechanical Properties

Polycarbonate has a higher impact resistance than Polyethylene Terephthalate, making it more suitable for applications where impact resistance is crucial. It also has a higher heat resistance and can withstand higher temperatures without deforming. On the other hand, Polyethylene Terephthalate has a higher tensile strength than Polycarbonate, making it more suitable for applications where strength is important. It also has a lower coefficient of friction, making it more resistant to wear and abrasion.

Chemical Properties

Polycarbonate is resistant to a wide range of chemicals, including acids, bases, and alcohols. It is also resistant to UV radiation, making it suitable for outdoor applications. On the other hand, Polyethylene Terephthalate is resistant to most solvents and chemicals, but it may degrade when exposed to certain chemicals, such as strong acids. It is also susceptible to UV radiation, which can cause it to degrade over time.

Processing

Polycarbonate can be easily molded and shaped using injection molding or extrusion processes. It can also be easily machined and fabricated using standard machining techniques. On the other hand, Polyethylene Terephthalate can also be easily molded and shaped using injection molding or extrusion processes. It can also be easily machined and fabricated using standard machining techniques.

Applications

• Polycarbonate is commonly used in applications such as eyeglass lenses, safety goggles, and bulletproof glass due to its high impact resistance and clarity.
• Polyethylene Terephthalate is commonly used in applications such as beverage bottles, food containers, and polyester fibers due to its high tensile strength and chemical resistance.

Conclusion

In conclusion, Polycarbonate and Polyethylene Terephthalate are two versatile thermoplastic polymers that have unique properties and characteristics. While Polycarbonate is known for its high impact resistance and excellent clarity, Polyethylene Terephthalate is known for its high tensile strength and chemical resistance. Both materials have their own set of advantages and disadvantages, and the choice between the two will depend on the specific requirements of the application. We hope this article has helped you understand the differences between Polycarbonate and Polyethylene Terephthalate.