Explanation

A polymer in which the repeating units of a macromolecule chain are bonded in a continuous length. However, it is not very strict to classify this kind of monomer only from its appearance. For example, polymer with short branched chains, such as a-olefin, isobutene, styrene, etc., should still belong to linear polymer although they have short branched chains, because they all have some characteristics of linear polymer, such as being able to dissolve, melt, etc; Both have large internal rotation degree of freedom; It has different flexibility (from flexibility to rigidity) and countless conformations due to the result of thermal motion. There is no chemical bond between the molecular chains of linear polymer, and the molecules can move (flow) relatively under heat or force, so it is easy to process and shape. The chemical properties of branched polymer are similar to linear molecules, but their physical and mechanical properties are different. Taking polyethylene as an example, branched polyethylene (low density) is different from unbranched, linear polyethylene (high density) in density, melting point, hardness, flow ability, etc. Generally speaking, linear polymer and some branched chain polymer have good rheological properties and are easy to process.

Classification