Bands PTFE dispersion

Fig.6 Bands on the free surface of compacted PTFE dispersion particles sintered at 380 °C followed by slow cooling. (Similar to Fig. IV-65 in Ref. [4])...

Fig. 8 Bands of dispersion PTFE prepared by sintering dispersed dispersion particles at 350 °C for 2 h on a glass slide. (Reprinted from Ref. [9] with permission from Wiley-Interscience)...

As manufactured, PTFE is of two principal types dispersion polymer, made by suspension polymerization followed by coagulation, and granular PTFE, polymerized and generally comminuted to a desirable particle size. Some details are given by Sperati. We have observed cast films of an aqueous colloidal dispersion and see that it consists of peanut-shaped particles, approximately 0.25 pm in size, which are composed of even finer particles. Electron micrographs of as-polymerized granular particles show three structures bands arranged in parallel, striated humps, and fibrils, some of which have the shish-kebab structure."... 

Fracture surfaces of both dispersion and granular high molecular weight PTFE that we described [4] had bands similar to those described by Bunn... 

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