Nature:
chemistry
Polycarbonate (PC) is a kind of polyester containing carbonic acid. Carbonic acid itself is unstable, but its derivatives (such as phosgene, urea, carbonic acid and carbonate) have certain stability.
According to the different alcohol structures, polycarbonate can be divided into aliphatic and aromatic.
Aliphatic polycarbonate. For example, polyethylene carbonate, polypropylene carbonate and their polymers have low melting point and glass transition temperature and poor strength, so they cannot be used as structural materials; However, due to its biocompatibility and biodegradability, it can be used as drug sustained-release carrier, surgical suture, bone support material and so on.
Polycarbonate is resistant to weak acid, weak base and neutral oil.
Polycarbonate is not resistant to ultraviolet rays and strong alkali.
PC is a linear carbonate polyester in which carbonate groups and other groups are alternately arranged. These groups can be aromatic, aliphatic or both. Bisphenol A PC is the most important industrial product.
PC is an almost colorless glassy amorphous polymer with good optical properties. PC high molecular weight resin has high toughness, the notched impact strength of cantilever beam is 600~900J/m, and the thermal deformation temperature of unfilled brand is about130 C, which can be increased by glass fiber reinforcement. The bending modulus of PC can reach more than 2400MPa, and the resin can be processed into large rigid products. When it is lower than100 C, the creep rate under load is very low. PC has poor hydrolysis resistance and cannot be used for products repeatedly subjected to high-pressure steam.
The main performance defects of PC are that its hydrolysis stability is not high enough, it is sensitive to nicks, and its resistance to organic chemicals and scratches is poor, and it will turn yellow after long-term exposure to ultraviolet rays. Like other resins, PC is easily soaked in some organic solvents.
PC material has flame retardancy and wear resistance. Oxidation resistance.
physics
Density:1.18-1.22g/cm3 Linear expansion ratio: 3.8× 10-5cm/℃
Polycarbonate is colorless, transparent, heat-resistant, impact-resistant and flame-retardant, and has good mechanical properties at ordinary use temperature. Compared with polymethyl methacrylate, polycarbonate has good impact resistance, higher refractive index and good processability, and has UL94 V-0 flame retardant performance without additives. However, the price of polymethyl methacrylate is lower than that of polycarbonate, and large devices can be produced by bulk polymerization.
Polycarbonate has poor wear resistance. Some equipment used for wearing polycarbonate needs special surface treatment.
classify
Anti-static PC, conductive PC, fiber reinforced fireproof PC, ultraviolet resistant and weather resistant PC, food grade PC, chemical resistant PC.
Main advantages
1, high strength and elastic coefficient, high impact strength and wide temperature range;
2. High transparency and no dyeing;
3. Low molding shrinkage and good dimensional stability;
4. Good fatigue resistance;
5. Good weather resistance;
6. Excellent electrical characteristics;
7, tasteless and odorless, harmless to the human body, in line with health and safety.