What is the difference between PE, PP and PC?What is the difference between PE, PP and PC?
Polyethylene is a kind of polymer which is polymerized by free radicals of vinyl monomers. Its English name is polyethylene, or PE for short. The synthetic raw material of PE comes from petroleum. Because of its abundant petroleum resources, its output ranks first.
Polyethylene is a late industrialization, but the fastest-growing plastic variety. LDPE is the earliest industrialized variety. At present, the varieties of polyethylene are: low density polyethylene (LDPE), high density polyethylene (HDPE), linear low density polyethylene (LLDPE), high molecular weight polyethylene (UHMWPE). In addition, there are vinyl acetate (EVA) and chlorinated polyethylene (CPE) and so on.
Performance of PE
1. General properties: PE resin is tasteless, non-toxic white or powder or particle, with white appearance, wax like feel, low water absorption, less than 0. 01%。 PE is easy to burn and its oxygen index is only 17. 4。
2. Mechanical properties: PE has general mechanical properties, low tensile strength, poor creep resistance, but good impact resistance. 3. Thermal properties: the heat resistance of PE is not good, which changes with the increase of molecular weight and crystallinity. The embrittlement temperature of PE is above - 50 ℃ and - 140 ℃ with the increase of molecular weight.
4. Electrical performance: PE has no polarity, so its electrical performance is very excellent. The dielectric loss is very low and can be used for high frequency insulation. 5. Environmental performance: PE belongs to alkane inert polymer, with good chemical stability. Under normal temperature, it can resist the corrosion of acid, alkali and salt aqueous solution. But not resistant to oxidants.
Polypropylene (PP) is a high molecular weight polymer. The main performances are as follows:
1. It has good heat-resistant performance, its melting point is 164-170, it can be boiled in water, sterilized by 120 steam, and it can be used for a long time at 100 temperature without deformation.
2. The most special mechanical property of polypropylene is bending fatigue resistance. At 0, it can bend back and forth for more than 1 million times without damage.
3. Excellent corrosion resistance, slightly lower oxidation resistance than polyethylene.
4. Due to its large surface luster, transparency, good mechanical strength, odorless, tasteless and non-toxic, it is in line with the national health standards. In addition to being used in the mechanical industry, it is also widely used in food, beverage, restaurant, hotel industry, table, board and equipment lining. 5. The density of polypropylene profile is only 0.93-0.96, which is the lightest one of engineering plastics. Therefore, the actual price is low and it is widely used.
Polycarbonate (PC) sheet has good mechanical properties, impact resistance and weather resistance. Keep all physical properties stable in the range of - 40 ℃ to + 120 ℃. The size is stable when heated. Light weight, PC board weight is 1 / 2 of the same thickness of glass, excellent electrical and dielectric properties, good light transmittance, 3 mm transparent board's light transmittance is 87%, flame retardant performance of V-2 self extinguishing.
Polycarbonate (PC) is a kind of engineering plastic sheet with excellent comprehensive properties. Therefore, it is widely used in explosion-proof safety equipment, helmets, masks, shields, taxi explosion-proof baffles. Insulating materials such as electrical appliances and instrument panel. Decorative materials such as: daylighting ceiling, advertising signs, light box. Anti noise materials such as: overhead road sound insulation screen, telephone booth, etc.
Polycarbonate (PC) sheet has the characteristics of secondary processing. The processing methods include heat setting, vacuum setting, cold bending and mechanical processing. There are embedding method, screw fastening method, sticking method, etc.
PP is the cheapest PC is the most expensive.