Acrylonitrile Styrene vs. Polystyrene

Attribute	Acrylonitrile Styrene	Polystyrene
Chemical Structure	Combination of acrylonitrile and styrene	Chain of styrene monomers
Physical Properties	Higher impact resistance	Brittle
Applications	Automotive parts, electronic housings	Packaging, disposable cutlery
Cost	Higher cost	Lower cost

Introduction

Acrylonitrile Styrene (AS) and Polystyrene (PS) are two commonly used thermoplastic polymers that have a wide range of applications in various industries. While they may seem similar at first glance, there are key differences in their attributes that make them suitable for different uses. In this article, we will compare the properties of AS and PS to help you understand their strengths and weaknesses.

Chemical Composition

Acrylonitrile Styrene is a copolymer made from a combination of acrylonitrile and styrene, while Polystyrene is a polymer made solely from styrene monomers. The addition of acrylonitrile in AS gives it improved chemical resistance and impact strength compared to PS. On the other hand, PS is known for its clarity and ease of processing, making it a popular choice for applications where transparency is important.

Physical Properties

AS has a higher heat resistance and impact strength compared to PS, making it a better choice for applications that require durability and toughness. AS also has better resistance to chemicals and solvents, making it suitable for use in harsh environments. PS, on the other hand, has a lower melting point and is more brittle than AS, but it is easier to process and has good dimensional stability.

Mechanical Properties

AS has a higher tensile strength and modulus compared to PS, making it a better choice for structural applications where strength is important. AS also has better resistance to creep and fatigue, making it suitable for long-term use under stress. PS, on the other hand, has lower impact strength and toughness, but it has good stiffness and dimensional stability, making it suitable for applications where rigidity is important.

Thermal Properties

AS has a higher heat deflection temperature and better resistance to high temperatures compared to PS, making it suitable for applications that require heat resistance. AS also has better resistance to flame and ignition, making it a safer choice for applications where fire safety is a concern. PS, on the other hand, has a lower heat deflection temperature and is more prone to deformation at high temperatures, but it has good electrical insulation properties.

Applications

AS is commonly used in automotive parts, electronic housings, and appliances where durability and chemical resistance are important. AS is also used in medical devices and industrial equipment where heat resistance and impact strength are required. PS, on the other hand, is used in packaging, disposable cups, and toys where clarity and ease of processing are important. PS is also used in insulation, signage, and consumer goods where rigidity and dimensional stability are required.

Conclusion

In conclusion, Acrylonitrile Styrene and Polystyrene have distinct attributes that make them suitable for different applications. AS is known for its high heat resistance, impact strength, and chemical resistance, making it a popular choice for durable and tough applications. PS, on the other hand, is valued for its clarity, ease of processing, and dimensional stability, making it a versatile choice for a wide range of applications. By understanding the properties of AS and PS, you can choose the right material for your specific needs.