AbstractMolecular weights of polytetrafluoroethylene are presently measured by a density method. We have found that polytetrafluoroethylene exhibits a sharply defined maximum relaxation time, τm, above its melting point. There is a clear correlation between τmat 380°C. and the “molecular weight”Mnof the polymer based on the measurement of density. However, log τmvs. logMngives a slope of 0.78 as against a value of 3.4 obtained for other polymers. Either polytetrafluoroethylene has flow behavior very different from other polymers or the molecular weight of the polymer based on the measurement of density is only appr
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