Polyvinyl chloride (PVC) is the world's third-largest synthetic polymer plastic (after polyethylene and polypropylene), producing approximately 40 million tons of PVC per year. PVC is a polymer formed by the polymerization of vinyl chloride monomer (VCM) in peroxides, azo compounds and other initiators, or under the action of light and heat according to the mechanism of free radical polymerization. Vinyl chloride homopolymers and vinyl chloride copolymers are collectively known as vinyl chloride resins.
PVC used to be the world's most produced general-purpose plastic and has a wide range of applications. PVC is available in both hard (sometimes abbreviated as RPVC) and soft. Rigid polyvinyl chloride is used in building pipes, doors and windows. It is also used in the manufacture of plastic bottles, packaging, bank cards, or loyalty cards. Adding plasticizers makes PVC softer and more elastic. It can be used in pipes, cable insulation, flooring, signage, gramophone records, inflatable products, and rubber substitutes.
In daily life, the need to distinguish between PVC and PE plastic film (bag) is the most contacted, and the simple method is:
1. Touch method
It feels lubricating to the touch, and the surface looks like a layer of wax (chemically called wax), which is a non-toxic polyethylene film bag, while the PVC film is a little sticky to the touch.
2. Jitter method
Shaking with your hands, the sound is brittle, and the texture floats easily is a polyethylene film bag. And the one with a low sound of shaking by hand is a PVC film bag.
3. Combustion method
It is flammable in case of fire, the flame is yellow, there is paraffin oil dripping when burning, and there is gas when the candle burns, it is a non-toxic polyethylene film bag. If it is not easy to burn, it will be extinguished when it is away from the fire, and the flame is green, which is a PVC film bag.
4. Immersion method
After immersing the plastic bag in the water and pressing it into the water by hand, the one that can rise to the surface is polyethylene, and the one that sinks to the bottom of the water is polyvinyl chloride (the density of polyethylene is less than water, and the density of polyvinyl chloride is greater than that of water; about 0.92 g/cm3 and 1.4 g/cm3 at room temperature, respectively).
A copper wire can also be taken and burned red in the fire, and then the copper wire is in contact with the plastic film used for the test to produce chemical changes, and then the copper wire dipped in the plastic component is put back into the flame. At this time, it is necessary to observe carefully, if there is a colorful and dazzling green flame, it means that this plastic material contains chlorine elements, which belongs to the polyvinyl chloride material.
Post time: 3月-13-2024
