Polycarbonate (PC) and Acrylic (PMMA) are two of the most common transparent plastics. Due to their similar appearance, they are often confused.
However, these materials exhibit significant differences in performance and application areas.
This article delves into the key distinctions between Polycarbonate vs Acrylic, helping readers make more informed material choices based on specific needs.
What is Polycarbonate?
Polycarbonate (PC) gets its name from the -CO3 group in its structure and is synthesized from bisphenol A and phosgene (COCl₂).
It is an almost colorless, glassy, amorphous polymer. PC high molecular weight resins exhibit excellent toughness, with a notch impact strength of 600-900 J/m on a cantilever beam.
The heat deflection temperature of unfilled grades is approximately 130°C.
It has excellent optical properties, with a light transmittance of 88% to 90%, making it ideal for applications requiring high transparency.
Application Of Polycarbonate
Due to its excellent properties, polycarbonate is widely used in various fields. For example:
- Electronics and Electrical Appliances: television cathode ray tubes, computer and DVD player housings, etc.
- Automotive Industry: car lights, dashboards, bumpers, and other components.
- Construction Industry: windows, soundproof panels, safety glass, etc.
- Medical Industry: surgical instruments, drug packaging, etc.
- Other Fields: sports equipment, optical devices, toys, and more.
What Is Acrylic？
Acrylic, also known as plexiglass, is chemically referred to as polymethyl methacrylate (PMMA). It is one of the earliest developed and most significant thermoplastic polymers.
Acrylic is renowned for its excellent transparency, chemical stability, weather resistance, ease of coloring, and processing, as well as its aesthetically pleasing appearance.
These qualities make it widely used in the construction industry.
Application Of Acrylic
Acrylic, due to its excellent properties, is widely used in various fields:
- Construction Industry: Light fixtures, display windows, soundproof doors and windows, skylights, telephone booths.
- Advertising Industry: Used for light boxes, signboards, directional signs, display stands.
- Transportation: High-speed train windows, car windows.
- Lighting : Fluorescent lights, chandeliers.
- Other Fields: Hotels, shopping malls, office buildings, museums, transparent walls, floors, signage.
Polycarbonate vs Acrylic:Property Comparison
Polycarbonate is a colorless and transparent material with excellent heat resistance, impact strength, and flame retardancy (rated BI).
It demonstrates outstanding mechanical properties within normal temperature ranges.
Compared to Acrylic ,polycarbonate offers superior impact resistance, higher refractive index, and better processing capabilities, while achieving UL94 V-2 flame retardancy without the need for additives.
Acrylic , on the other hand, boasts a transparency of up to 92%, offering exceptional optical clarity and surface gloss. Compared to polycarbonate, acrylic is more rigid, has better scratch resistance, and exhibits outstanding weather and chemical resistance, allowing it to withstand prolonged exposure to UV rays and corrosive substances.
Additionally, acrylic is highly processable, suitable for cutting, laser engraving, and thermoforming complex shapes. It is also lighter and more cost-effective, making it a preferred choice in various applications.
Below is a table comparing the physical properties of polycarbonate and acrylic:
Properties | Polycarbonate | Acrylic |
Density（g/cm3） | 1.18－1.22 | 1.15-1.19 |
Melting Point（℃） | 220-230 | 160-180 |
Tensile Strength（MPa） | 64.7-68.7 | 50-75 |
Water Absorption（%） | 0.15-0.24 | 0.3-0.4 |
Shrinkage（%） | 0.5-0.7 | 0.2–0.6 |
Impact Strength (J/m) | 600~900 | 20-30 |
Heat Deflection Temp (℃) | 135(Low Temp -45°C) | 96 |
Acrylic vs Polycarbonate:Cost Analysis
Price is an important factor to consider when selecting materials. Therefore, we will conduct a detailed cost analysis of polycarbonate and acrylic from the perspectives of raw material cost and processing cost.
1.Raw Material Cost
Polycarbonate (PC) has a higher raw material cost due to its complex production process, such as the reaction between bisphenol A and phosgene.
In contrast, acrylic (PMMA) is produced through simpler methods like bulk or suspension polymerization, with readily available raw materials and mature production technology, making it more cost-effective.
Typically, PC sheets cost around $3–$5 per kilogram, while acrylic sheets are priced at $1.5–$3 per kilogram (prices may vary depending on region and purity).
2.Processing Cost
Polycarbonate requires higher processing temperatures and more sophisticated equipment, such as polycarbonate injection molding requires the use of an injection molding machine.
Additionally, achieving scratch resistance and weatherability often necessitates surface treatments (e.g., coatings), further increasing costs.
In comparison, acrylic is easier to process, allowing for simple cutting, thermoforming, drilling, or laser engraving, with lower equipment and processing requirements, resulting in lower overall costs.
In summary,polycarbonate has higher material and processing costs, but its superior performance makes it ideal for long-term use and high-performance applications.
Acrylic is more economical due to its lower cost and easier processing, making it a suitable choice for applications with lower strength and durability requirements.
Differences Between Acrylic And Polycarbonate In Processing Methods
Bulk polymerization is the most common process for producing acrylic.
The monomer (methyl methacrylate) and a catalyst (usually an organic peroxide) are introduced into a mold, where they undergo a polymerization reaction under heat to form acrylic plastic.
The molded acrylic sheets then require curing, with thinner sheets typically taking 10–12 hours, while thicker sheets may take several days.
Polycarbonate sheets, on the other hand, are primarily manufactured using the extrusion process.
Polycarbonate resin is melted in an extruder and forced through a die to create sheets with consistent width, length, and thickness.
This process allows for the production of sheets in various sizes, colors, gloss levels, and surface textures.
Once extruded, the sheets can be further processed to create the final products.
Which Is Safer, Polycarbonate Or Acrylic?
Polycarbonate and acrylic each have their own advantages and disadvantages in terms of safety, and the choice depends on the specific application.
Polycarbonate safety is reflected in its excellent impact resistance, with an impact strength 250 times that of glass and 30 times that of acrylic of the same thickness, making it ideal for high-strength applications such as bulletproof windows.
Additionally, polycarbonate naturally achieves UL94 V-2 flame retardancy without additives and offers superior heat resistance, with a continuous operating temperature of up to –115°C (240°F).
Acrylic,offers higher rigidity and better scratch resistance, making it more suitable for applications where long-term optical clarity is required.
Moreover, it has strong chemical stability, resisting acids and alkalis, and releases no harmful substances, making it a safe choice for food-grade and medical applications.
However, acrylic’s heat resistance and flame retardancy are inferior to polycarbonate, making it prone to deformation or burning in high-temperature environments.
All in all, polycarbonate is better suited for applications requiring high strength, heat resistance, and flame retardancy, while acrylic excels in scenarios emphasizing optical clarity and chemical stability.
Recyclability Of Polycarbonate And Acrylic
Generally, both polycarbonate and acrylic plastic are recyclable materials.
However, in practice, the recycling technology and infrastructure for acrylic are not well-developed, resulting in incomplete recycling.
This leads to a significant amount of discarded acrylic products being incinerated or landfilled, causing environmental pressure.
In contrast, the recycling system for polycarbonate is relatively more established, allowing for substantial resource reuse through mechanical or chemical recycling methods.
How To Choose Between Polycarbonate Or Acrylic？
In conclusion, both polycarbonate and acrylic have their own advantages and limitations, and the choice between them should be carefully weighed based on project requirements.
Polycarbonate stands out for its exceptional strength and impact resistance, making it ideal for safety applications and demanding environments.
While it is relatively soft, it is resistant to scratches. Acrylic, on the other hand, is highly valued for its excellent optical transparency and cost-effectiveness, though its tendency to crack should be considered.
Therefore, when selecting a material, factors such as durability, aesthetics, and budget constraints should be taken into account to ensure the best choice.