Effect of Explosive Processing on the Structure and Properties of Ultrafine Polytetrafluoroethylene

摘要

The effect of explosive pressing on a powder of Forum ultrafine polytetrafluoroethylene (UPTFE) is studied. It is found that the processing leads to the formation of a crust on the surface of the sample; its morphology and phase and chemical composition differ from those of the original sample. Regions of flattened particles linked by fibers, which resemble craze structures, are detected in a dark film. In addition to PTFE, iron compounds are contained in these structures. The molecular structure of the polymer is generally preserved; however, the amount of middle-molecular-weight fractions in the material increases owing to a decrease in the low- and high-molecular-weight fractions. After processing, a new type of disorder is formed and the crystallinity of the material generally increases.