[Chemical Knowledge]：The nature, use, upstream and downstream raw materials, storage methods of polycarbonate, what is generally used for polycarbonate

Polycarbonate properties

Polycarbonate (Polycarbonate, PC) is a kind of polymer material, which is widely used in various fields because of its unique physical and chemical properties. Polycarbonate has excellent mechanical properties, especially its high impact resistance and excellent toughness, making it excellent in applications with high strength requirements. The optical transparency of polycarbonate is excellent, and the light transmittance can reach more than 90%, which makes it widely used in the optical field. Polycarbonate also has good heat resistance and weather resistance, and can be used for a long time in the temperature range of -40°C to 120°C. Polycarbonate also has excellent electrical insulation properties, making it an ideal material for the electronics and electrical industries.

Polycarbonate use

Due to its excellent comprehensive properties, polycarbonate has a wide range of applications in many fields. In the construction field, polycarbonate is often used to make transparent roofs, skylights and curtain walls. In the electrical and electronic field, polycarbonate is used to manufacture electrical housings, connectors and insulation materials. In the automotive industry, polycarbonate is used to make lamp covers, instrument panels and interior trim parts. Polycarbonates also have important applications in medical devices, optical lenses, CD and DVD discs, office equipment, and safety protection products such as bulletproof glass. These diverse fields of application show the importance of polycarbonate in modern industry and in everyday life.

Polycarbonate upstream raw materials

The main raw materials for the production of polycarbonate are bisphenol A(BPA) and phosgene (or carbon dioxide). Bisphenol A is an important organic chemical raw material, which is mainly prepared by the reaction of phenol and acetone under the action of acid catalyst. Phosgene (phosgene) is produced by the reaction of carbon monoxide and chlorine. In the polymerization reaction, bisphenol A and phosgene produce polycarbonate by a transesterification reaction or an esterification reaction. With the development of green chemistry, more and more studies have focused on the preparation of polycarbonate by phosgene-free method using carbon dioxide as a carbon source. This method not only reduces the dependence on toxic phosgene, but also has environmental advantages.

Polycarbonate Downstream Products

The downstream products of polycarbonate cover many fields, from electrical and electronic products, auto parts to construction materials and daily consumer goods. Specifically, electronic and electrical products such as mobile phone shells, notebook shells, display frames, etc.; auto parts such as car lampshades, dashboards, interior decoration parts, etc.; building materials such as transparent roofs, curtain walls, sound insulation panels, etc. Polycarbonate is also used in the manufacture of optical lenses, sunglasses, protective masks, medical devices such as disposable syringes and blood oxygen probes, and packaging materials. The diversified downstream products not only demonstrate the wide application of polycarbonate, but also reflect the diversity and broad prospects of its market demand.

Polycarbonate production process

There are two main processes for the production of polycarbonate: interfacial polycondensation and melt polycondensation. The interfacial polycondensation method produces polycarbonate by the reaction of bisphenol A and phosgene at the interface, which has the advantages of low reaction temperature and high product purity, but phosgene is toxic and harmful to the environment and operators. The rule of melt polycondensation is that bisphenol A and carbonic acid diester (such as diphenyl carbonate) react at high temperature to produce polycarbonate, which avoids the use of phosgene, is more environmentally friendly and simplifies the process. The melt polycondensation method requires high reaction equipment and operating conditions. At present, the melt polycondensation method has gradually received more attention because of its environmental protection and process improvement.

Polycarbonate storage method

Since polycarbonate is sensitive to temperature and humidity, its storage conditions require special attention. Polycarbonate should be stored in a cool, dry, well-ventilated warehouse, avoid direct sunlight and high temperature environment to prevent material aging and performance degradation. Polycarbonate needs to be sealed and packaged to prevent moisture, because moisture absorption will affect its mechanical properties and processing properties. During transportation, violent vibration and impact should be avoided to prevent scratches or cracks on the surface of the material. Fire prevention facilities should be set up in the warehouse, because although polycarbonate has certain flame retardancy, it may still burn under high temperature or open flame conditions.

Polycarbonate Market Prospects

With the continuous development of industry and technology, the market demand for polycarbonate continues to grow. In the automotive industry, the lightweight trend is driving the demand for high-performance materials, and polycarbonate is an ideal choice due to its excellent mechanical properties and lightweight characteristics. In the field of electronic and electrical, the development of 5G technology and smart devices has also promoted the demand for highly transparent and heat-resistant materials. The enhancement of environmental awareness and the strictness of regulations have promoted the development of phosgene-free processes. It is expected that more environmentally friendly polycarbonate products will enter the market in the future. Polycarbonate with its unique properties and a wide range of applications, the future market prospects.

Polycarbonate environmental challenges

Although polycarbonate has many advantages, it also faces environmental challenges during its production and use. The traditional phosgene production process involves toxic chemicals, which has environmental pollution and safety hazards. The degradation of polycarbonate is poor, and waste disposal is an important problem. At present, researchers are working on the development of biodegradable polycarbonate and green production processes to reduce environmental impact. For example, the use of carbon dioxide and plant-derived raw materials to produce polycarbonate, or the recycling of polycarbonate through chemical recovery technology. With the advancement of technology and the improvement of environmental awareness, the polycarbonate industry will gradually move towards sustainable development.

Conclusion

Polycarbonate with its excellent physical and chemical properties has been widely used in many fields, from building materials, electrical and electronic products to the automotive industry and medical equipment, its importance is self-evident. The upstream raw materials required for the production of polycarbonate are mainly bisphenol A and phosgene, while its downstream products cover many industries. Although polycarbonate faces challenges in storage and environmental protection, with the progress of technology and the development of green technology, the application prospect of polycarbonate is still broad. In the future, the polycarbonate industry will pay more attention to environmental protection and sustainable development in meeting the market demand.