Thermoplastic polyurethane elastomer TPU can be divided into polyester type and polyether type according to molecular structure, and can be divided into injection grade, extrusion grade and blow molding grade according to processing methods.
PC is the abbreviation of polycarbonate, and the English word for polycarbonate is PC engineering plastic. PC material is actually a kind of engineering plastics. As a widely used material in the world, PC has its own characteristics, advantages and disadvantages. PC is an amorphous thermoplastic resin with excellent comprehensive properties, which has excellent electrical insulation, ductility, dimensional stability, chemical corrosion resistance, high strength, heat resistance and cold resistance. It also has the advantages of self-extinguishing, flame retardant, non-toxic and colorable. You can see the shadow of PC plastic in every corner of your life, and the characteristics of large-scale industrial production and easy processing also make it extremely cheap. Its strength can meet all kinds of requirements from mobile phones to bulletproof glass. The disadvantage is that compared with metal, the hardness is insufficient, which makes the appearance easier to scratch, but the strength and toughness are good. Whether it is heavy pressure or general knocking, as long as you don't try to hit it with stones, it is enough for wide-wave light-transmitting optical instruments in the application field. As an engineering plastic with good transparency, PC is widely used as the substrate of optical disks in the world. Not only can CD, VCD and DVD discs be prepared, but also can be used as the substrate of high-density recording discs, especially the * * * polymer generated by grafting PC with styrene has excellent application effect. PC sheet is especially suitable for making spectacle lenses. The hardness and scratch resistance of PC can be improved by introducing siloxane groups into the molecular chain of PC. As a kind of high refractive index plastic, PC is used to make the core material of high temperature resistant optical fiber. If the C-H chain in PC molecular chain is replaced by C-F chain, the absorption of visible light can be reduced and the signal loss during transmission can be effectively reduced. In addition, PC has good light transmission, and has a wide range of applications and potential in transparent window materials, curtain walls of high-rise buildings, transparent building materials for airports and stadiums. In the future, the emphasis will be on improving the surface hardness and antistatic properties.
Due to the good electrical insulation performance of polycarbonate, flame-retardant and environment-friendly communication appliances are widely used in the field of communication and telecommunications equipment. At present, PC has largely replaced the original phenolic plastics. In the future, flame retardant PC materials will be developed in the field of communication appliances, so pollution-free flame retardant PC materials will become the development focus. Bromine flame retardants are rarely used because of their toxicity, while halogen-free and environmentally friendly phosphorus flame retardants will obviously reduce the thermal deformation temperature and impact strength of PC, so silicon flame retardants are more suitable. In addition, with the lightweight and miniaturization of communication appliances, higher requirements are put forward for PC materials. At present, PC/ABS alloy is especially suitable for communication appliances and aerospace industry.
Auto parts with metallized surface, PC surface has good metallic luster and high strength, and is widely used in various auto parts. However, its impact toughness will decrease during electroplating. Therefore, the mixed modification of elastomer and PC*** will disperse the cracking stress, and its impact toughness will not decrease even after electroplating. Therefore, electroplating grade PC resin has great development prospects. In addition, PC with metallized surface can also be used as a shielding material for electromagnetic waves and applied to computers.
For food containers with low residue of harmful substances, industrial synthetic PC is bisphenol. Because a small amount of unreacted monomer bisphenol A remains in the synthesis process of resin, it is easy to dissolve out when used as drinking water bucket and food container, which affects people's health. Therefore, it is very promising to develop sanitary PC resin for producing and using food containers such as drinking buckets.
Anti-crack and embrittlement medical devices, PC has many excellent properties and has been used in medical devices at present. Because of its poor chemical resistance, it is easy to cause internal stress cracking in the presence of chemical substances. For example, PC is used in medical devices such as artificial dialyzer and artificial lung to solve the aging phenomenon of cracks caused by high temperature disinfection. If these shortcomings are overcome, the application of PC in medical devices can be rapidly expanded.