plastic definition
The plastic is made of monomers as raw materials, polymer by polyaddition or polycondensation polymerization (macromolecules), commonly known as plastic resin (plastics) or (resin), can freely change the composition and form style, composed of synthetic resin and filler, plasticizer, stabilizer, lubricant, pigment and other additives.
The main component of plastics is resin. The term was first resin secrete by animal and plant lipid and its name, such as rosin, shellac, resin is not mixed with various additives and polymer compounds. The resin accounts for about 40% to 100% of the total weight of the plastic. The basic properties of plastics are mainly determined by the nature of resins, but additives also play an important role. Some plastics are made up of synthetic resins, with or without additives, such as perspex and polystyrene.
The so-called plastic, in fact, it is a kind of synthetic resin, the shape is similar to the natural resin in pine resin, through chemical means of artificial synthesis, and is called plastic.
Main feature
Most plastics are lightweight, chemically stable, and not rust;
Good impact resistance;
It has good transparency and wear resistance;
Good insulation and low thermal conductivity;
It has good formability, good coloring and low processing cost;
Most of the plastics have poor heat resistance, high thermal expansion rate and easy combustion;
It has poor dimensional stability and easy deformation;
Most plastics have low temperature resistance, brittleness at low temperature and aging easily;
Some plastics are soluble in solvents.
Plastics can be classified into two types: thermosetting and thermoplastic. The former cannot be reshaped and the latter can be repeated. The physical extensibility of thermal plasticity is large, generally in 50%~500%. The force does not vary linearly at different elongation rates.
The different properties of plastics determine its use in the industry. With the progress of technology, the plastic modification has not been stopped. Hopefully, in the near future, plastics will be more widely used, and even replace steel and other materials, and will no longer pollute the environment.
