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High Molecular Compound
Polymer compounds, referred to as polymers, also known as polymer polymers, generally refers to the relative molecular weight of up to several thousand to several million compounds, the vast majority of polymer compounds are a mixture of many homologues with different relative molecular weights, so the relative molecular weight of polymer compounds is the average relative molecular weight. Polymer compounds are made up of hundreds of atoms connected to each other in covalent bonds, and although their relative molecular mass is large, they are all connected in simple structural units and in a repetitive manner.
The molecules of high molecular compounds are much larger than those of low molecular organic compounds. Generally, the relative molecular mass of organic compounds does not exceed 1000, while the relative molecular mass of polymer compounds can be as high as 104 ~ 106. Due to the large relative molecular weight of polymer compounds, there are great differences in physical, chemical and mechanical properties with low molecular compounds.
Although the relative molecular mass of polymer compounds is large, the composition is not complex, and their molecules are often made of specific structural units repeatedly connected by covalent bonds.
The number of links contained in the molecular chain of the same polymer compound is not the same, so the polymer compound is essentially a mixture of many compounds with the same chain structure and different polymerization degrees, and its relative molecular weight and polymerization degree are average values.
Polymer compounds are almost non-volatile and often exist as solid or liquid at room temperature. Solid polymers can be divided into crystalline and amorphous states according to their structure and morphology. The molecular arrangement of the former is regular and orderly; The latter molecules are arranged randomly. The same polymer compound can have both crystalline and amorphous structures. Most synthetic resins have an amorphous structure.
The atoms of the polymer chain are combined by covalent bonds, and the polymer chain generally has two different shapes: chain type and body type.
A large number of polymer compounds used as materials in the world today are low molecular organic compounds prepared from coal, oil, natural gas and other starting raw materials, and then made by polymerization. These low molecular compounds are called "monomers", and the polymer compounds generated by their polymerization reaction are also called polymers. Generally, the polymerization reaction is divided into two categories: addition polymerization and condensation polymerization, referred to as addition polymerization and condensation polymerization.
