Low-Molecular Fluoropolymers: Structure and Thermal Properties

The main representatives of low-molecular-weight fluoropolymers obtained by the thermogasdynamic method of polytetrafluoroethylene (PTFE) pyrolysis, radiation polymerization of tetrafluoroethylene (TFE) in various solvents, and direct fluorination of low-molecular-weight paraffins are characterized. The features of the morphology, structure, molecular chain length, and thermal properties of the polymers obtained by various methods are shown. During repeated heat treatment of low-molecular weight fluoropolymers (heating to a temperature when the process of weight loss ends), regardless of the method of obtaining the polymer, new more dispersed low-molecular-weight fluoropolymers are formed, which may not differ from the original ones (fluoroparaffins) or differ in a number of characteristics (telomers, UPTFE (PTFE converted into low-molecular ultrafine powder) fractions). A new low-molecular-weight product is formed during the pyrolytic processing of high-molecular-weight copolymers of ethylene with TFE. The product is a low-molecular-weight form of ETFE, differing from the original objects in morphology, molecular chain length, and thermal properties.