Classification And Physical Properties Of Plastics

One, What is plastic?
Plastic is a plasticity of man-made polymer organic compounds (resins).
Plastic refers to the organic synthetic resin as the main component, with or without the addition of other materials (additives) and the composition of man-made materials. It is usually molded into a device with a certain shape under heating and pressure.

The so-called plasticity refers to the property of deforming when a force is applied and not returning to its original shape after the force is removed, as in the case of clay. The so-called elasticity (elasticity), refers to the application of a certain degree of force on the deformation, but the withdrawal of the applied force is restored to its original state, this property is called elasticity (eg: rubber), with the elasticity of the object is called an elastomer (eg: elastic band); plastic is the use of this plasticity produced when heated, processed into various shapes.

Second, the source of plastic
Plastic is made of low molecular organic compounds (such as: ethylene, propylene, styrene, vinyl chloride, vinyl alcohol, etc.) in certain conditions polymerization of high molecular organic compounds (polymers).
The molecules that make up plastics are polymers with molecular weights above 10,000, so plastics are polymer compounds (polymers). General plastic molecules contain carbon (C) atoms and hydrogen (H) atoms, some plastic molecular structure contains a small amount of oxygen (O), sulfur (S) atoms. The basic raw material of plastics is low molecular carbon, hydrogen compounds, it is from oil, natural gas or coal crackers in the extraction and synthesis of man-made resins.

Third, the development process of plastics
The development and production time of different plastics.
1920-1933: polystyrene (PS), polyvinyl chloride (PVC), polyethylene (PE), ethylene vinyl acetate copolymer (EVA), polypropylene (PP).
1935:Acrylonitrile-butadiene-styrene copolymer (ABS)
1939:Polyethylene terephthalate copolymer (ABS)
1949:Polyamide (Nylon)
1950:Poly(methyl methacrylate)(Acrylic)
1956:Polyoxymethylene (POM)
1958:Polycarbonate (PC)
1964:Polyphenylene Oxide (PPO)
1965:Polysulfone(PSF)
1975:Polybutylene Terephthalate (PBT)
1985:Liquid Crystal Plastics (LCP)
1994:PET modified to injection molding grade (PETG)
1995:Super Elastic Polyoxymethylene (TPOM)
1996:Transparent rigid polyvinyl chloride (PVC)
After 1960, the application of plastics and processing technology has been a rapid development.

Fourth, the classification of plastics
At present, plastic has developed to more than 300 kinds of plastics, the most commonly used plastics have more than a dozen kinds.