What is PC?

Core Properties and Production Process of PC

1. Raw Material Sources

    

   The mainstream feedstocks are bisphenol A (a petroleum-based chemical product) and phosgene (or diphenyl carbonate), making it a typical petroleum-based plastic. With the advancement of environmental protection technologies, bio-based PC grades produced from bio-derived bisphenol A have also emerged, further enhancing its sustainability.
    
2. Production Process

    

   The two dominant industrial processes are interfacial polycondensation and melt transesterification. Interfacial polycondensation uses bisphenol A and phosgene as raw materials to conduct polycondensation at the water-organic phase interface for PC production, yielding products with high purity and stable performance. Melt transesterification employs bisphenol A and diphenyl carbonate as feedstocks to carry out transesterification under molten high-temperature conditions; it avoids the use of highly toxic phosgene, making it a more eco-friendly and mainstream direction for green production. After polymerization, the product undergoes secondary processing including pelletizing, extrusion, injection molding and thermoforming to be made into various finished products.
    
3. Key Properties

    

   Its core advantages lie in a balance of rigidity and toughness, high transparency and good heat resistance: it boasts extremely high impact strength (known as "bulletproof plastic") and can withstand severe impact without easy fracture; its light transmittance reaches 88%–90% (close to that of glass), and it is resistant to UV aging; its heat deflection temperature is approximately 120–130°C, enabling it to maintain stable performance over a wide temperature range (-40°C to 120°C). It also exhibits good dimensional stability and chemical corrosion resistance. Its main drawback is poor scratch resistance, with surface scratches easily formed, which can be improved through coating modification.
    
4. Application Scenarios

    

   PC is used across multiple fields including electronics and electrical appliances, automotive, construction, medical care and daily necessities, such as electronic device housings (computers, mobile phones, power banks), automotive lamp shades, instrument panels, architectural lighting panels, baby bottles (food-grade PC must comply with bisphenol A residual standards), medical devices (syringes, surgical instrument trays) and safety goggles.
    

Core Differences Among PC, PEL, PAL and PL (Polylactic Acid)

1. Molecular Structure and Raw Material Differences
    
   • PC: The main chain has carbonate groups as repeating units; mainstream feedstocks are petroleum-based (bisphenol A + phosgene).
   • PL (Polylactic Acid): The main chain has ester bonds as repeating units; feedstocks are fully bio-based (corn, cassava, etc.).
   • PEL: The main chain has ester bonds as repeating units, with a polyester elastomer structure; it can be produced from bio-based feedstocks.
   • PAL: The main chain consists of amide bonds (rigid segments) + elastomer segments (flexible segments), with a copolymer structure; feedstocks are mainly bio-based.
    
2. Performance Focus Differences
    
   • PC: Core strengths are high impact strength, high transparency and good heat resistance, with a balanced rigidity and toughness; it has no biodegradability (traditional grades).
   • PL: Core strengths are complete biodegradability + good processability, with moderate rigidity, no elasticity and poor heat resistance (55–60°C).
   • PEL: Core strengths are high elasticity + degradability, with the best elastic recovery rate but the weakest rigidity.
   • PAL: Core strength is a balance between rigidity and elasticity, with higher strength and wear resistance than PEL, and better elasticity than bio-based nylon (extended comparison).
    
3. Application Scenario Differences
    
   • PC: Suitable for structural/functional components requiring high strength, transparency and heat resistance (electronic housings, automotive lamp shades, medical devices).
   • PL: Suitable for disposable eco-friendly products and packaging materials (biodegradable scenarios with no elasticity requirements).
   • PEL: Suitable for eco-friendly scenarios requiring high elasticity (degradable elastic packaging films, biomedical elastic components).
   • PAL: Suitable for eco-friendly scenarios requiring both strength and elasticity (automotive elastic structural parts, high-end stretch fabrics).