Polycarbonate vs. ABS: Material Differences and Comparisons

Polycarbonate (PC) and ABS (acrylonitrile butadiene styrene) are both thermoplastic polymers used for manufacturing applications. PC is typically injection molded or thermoformed into the desired shape. It is used in high-impact applications and where optical transparency is required. ABS is usually injection molded or extruded. It is more rigid than polycarbonate. ABS performs well in applications that require toughness, and heat resistance.

When considering polycarbonate vs. ABS for manufacturing parts, it can be difficult for Xometry customers to choose between them. This article will compare and contrast the structure, manufacturing processes, material properties, applications, cost, recyclability, and sustainability of polycarbonate vs. ABS to help you make the right choice.

What Is Polycarbonate? 

Polycarbonates are thermoplastic polyesters with excellent mechanical properties. PC brand names include Lexan®, Makrolon®, and Palgard™. Polycarbonates are formed when phosgene gas reacts with the precursor bisphenol A (BPA). Alternatively, BPA and diphenyl carbonate can undergo transesterification (the conversion of a carboxylic acid ester into a different carboxylic acid ester) to produce PC. Although it is possible to make polycarbonates using non-BPA diols.

PC is strong and durable. It lends itself to applications that involve high local plastic deformation resulting from impact loading owing to its highly non-crystalline structure. The unorganized and loosely packed polymer chains in PC’s structure allow it to absorb considerably more energy than materials with semi-crystalline structures, and so is more impact resistant. The amorphous structure of PC results in it being transparent as light is able to pass through the spaces between its polymer chains, therefore it is suited to applications where transparency is a key requirement. PC’s structure also results in its high glass transition temperature, making it a good material to use in high-temperature environments. PC can be processed by metal-forming methods such as press brake bending and can be injection molded, extruded, 3D printed (FDM), and machined. However, polycarbonate requires high temperatures and special equipment to be extruded using 3D printers due to its high glass transition temperature. PC is used to manufacture prototypes as it is easily processed at room temperature using sheet metal machining techniques. 

Xometry does polycarbonate CNC machining, polycarbonate 3D printing, and polycarbonate laser cutting. It's a very common material that our customers like to use.

Common applications of PC include bullet-proof windows, medical devices, safety equipment (visors, eyewear, and screens), electronics, and applications requiring transparency and shatter resistance. For more information, see our guide on What is Polycarbonate Plastic.

Figure 1 shows an examples of polycarbonate 3D printing:

Different grades of PC are available that range from low to high toughness, flexibility, and strength, with additives enhancing toughness, ductility, chemical resistance, and heat resistance. Special coatings can be added to reduce scratching and increase chemical resistance.

What Is ABS?

ABS is a thermoplastic polymer with advantageous properties such as durability, rigidity, and good dimensional stability. ABS is produced by the polymerization of acrylonitrile and styrene in the presence of polybutadiene. The proportions of each monomer can be adjusted to produce different grades of ABS, each providing different mechanical properties. For example:

1. More acrylonitrile results in more polar bonds formed between nitrile chains to increase the strength. 
2. More styrene provides increased rigidity and a shiny surface finish. 
3. More acrylonitrile results in improved fatigue resistance, chemical resistance, and high-temperature performance as measured by its heat deflection temperature. 

ABS can be combined with different materials to increase certain properties. For example, PC and ABS can be combined in different ratios to form thermoplastic blends that exhibit a mix of their constituents’ mechanical properties. PC-ABS blends offer increased ductility, processability, and scratch resistance from ABS, heat resistance, and toughness from PC, and retain the high strength and impact resistance of both materials.

ABS is a strong and rigid plastic that offers a high-quality, scratch-resistant surface finish. It is also dimensionally stable across a wide range of temperatures, ensuring that it does not warp. Its high rigidity and strength make it resistant to deformation under both tensile and compressive loads. The stiffness of ABS can be increased through the addition of glass fibers. ABS can also take on other surface finishes including matte and gloss. ABS can also be dyed using a variety of pigments.

The most common manufacturing techniques used with ABS are injection molding and FDM (fused deposition modeling) 3D printing. ABS is well suited to 3D printing because it can be extruded at relatively low temperatures, so the process does not require specialized high-temperature-rated equipment. ABS is a common 3D printing material at Xometry, check out our service page on ABS 3D printing to get your quote today.

ABS can be used in many applications. It resists warping across the wide range of temperatures that vehicles experience. This dimensional stability makes it very useful for automotive parts such as dashboards and steering wheels. ABS is also used in applications where scratch resistance and the visual appeal is important, such as: light switches, office equipment, and children’s toys. For more information, see our guide on What is ABS Plastic.

Polycarbonate vs. ABS: Applications and Uses

Polycarbonate and ABS are both adaptable to a wide range of applications. It can be difficult to decide which plastic best matches a specific use case. Listed below are some common applications that can make use of either polycarbonate or ABS:

1. Medical equipment and devices
2. Luggage
3. Pipes and tubing

Examples of exclusive uses and applications of polycarbonates are:

1. Glass Alternative: PC is used as an alternative to glass due to its high transparency and impact resistance.
2. Construction Material: The high thermal resistance of polycarbonate makes it suitable for use in construction, typically as an insulation layer. PC can also be easily shaped to form decorative panels and arches.
3. Food Containers: PC has a high glass transition temperature and can retain its shape when exposed to hot food. Its transparency allows food to be visible during storage.

Examples of exclusive uses and applications of ABS are

1. Automotive Interiors: ABS is suited to automotive interiors as it has a good surface finish and is resistant to scratching.
2. Children’s Toys: ABS is naturally UV resistant which results in greater longevity of outdoor toys. Pure ABS is naturally white and so is an excellent carrier for a wide range of pigments.
3. Housings for Electronic Devices: Electronic device housings are often made from ABS owing to their good UV resistance, which ensures the mechanical performance of the housing does not degrade after long-term UV exposure. 

Polycarbonate vs. ABS: Physical Properties 

Table 1 below shows the material properties of polycarbonate vs. ABS:

Polycarbonate has greater tensile strength, higher heat deflection temperature, and flexibility than ABS. ABS, on the other hand, has a higher natural UV (ultraviolet) resistance and rigidity compared to polycarbonate.

Recyclability and Sustainability

Polycarbonate and ABS are both fully recyclable. They can be heated to a temperature above their melting points to form liquid thermoplastics. Both can also be immediately injection molded into a new desired shape or be used to form pellets for later use. PC and ABS can undergo the recycling process multiple times without degradation of their material properties, which makes them ideal choices for sustainable manufacturing.

PC can also be broken down chemically using a zinc-based catalyst. Pure BPA can be isolated through water recrystallization and drying cycles, with environmentally friendly waste products produced, including dimethyl carbonate. The isolated BPA can then undergo a reaction with sodium hydroxide and phosgene to form PC, which can be thermoformed into pellets or new parts.

However, both ABS and PC have a resin identification code (RIC) of 7, meaning that recycling facilities may not be widely accessible in all parts of the world. RIC 7 plastics are not currently recycled across the majority of the USA.

Costs

Polycarbonate costs approximately 50% more than ABS, with both being relatively inexpensive materials. Standard PC sheet material typically costs $31 per kilogram, and standard PC pellets cost around $1.52 per kilogram. A reel of ABS used for consumer 3D printing typically costs around $20 per kilogram, and standard ABS pellets cost around $0.90 per kilogram. PC-ABS blends are cheaper than using PC alone as the addition of ABS reduces the cost of material per kilogram.

Alternative Materials You Could Use Instead of Polycarbonate and ABS

Potential substitute materials are available for both polycarbonate (PC) and ABS. These are:

1. Polymethyl Methacrylate (PMMA): PMMA, acrylic or Perspex® may be a suitable alternative to PC for sheet materials due to its optical clarity. PMMA is a good alternative when the intended application does not require high-impact resistance or toughness. PMMA is more brittle than PC and is thus more likely to crack in service.
2. Acrylonitrile Styrene Acrylate (ASA): ASA has properties similar to ABS such as high impact strength and good performance over a range of temperatures. In some exterior automotive applications, ASA may be favored as it has better performance in adverse weather and environmental conditions than ABS owing to its higher UV resistance and, depending on the grade of ASA used, lower water absorption.

Xometry provides a wide range of manufacturing capabilities and services - including ABS and polycarbonate 3D printing, machining, and cutting for all of your prototyping and production needs. Get your instant quote today.

Copyright and Trademark Notices

1. PERSPEX® is a registered trademark of PERSPEX INTERNATIONAL LIMITED.
2. Lexan™ is a trademark of GE Plastics.
3. Makrolon® is a registered trademark of COVESTRO INTELLECTUAL PROPERTY GMBH & CO. KG.
4. Palgard™ is a trademark of PALRAM INDUSTRIES LTD.

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