Shulz distribution

MWDs p x) are plotted against reduced size x = 1/ L) of the chains for a number of densities (f) and are seen to collapse nicely on a single master curve, Fig. 5(a). The exponential decay, expected from Eq. (16) at high densities, is clearly observed in contrast to the indicated exp(-7x) behavior. This finding is in agreement with the simulations in Id [62], but it contradicts the predictions of Gujrati [15] according to whom the Shulz distribution, Eq. (16b), holds independently of the overlap. 

The Fischer-Tropsch process can be considered as a one-carbon polymerization reaction of a monomer derived from CO. The polymerization affords a distribution of polymer molecular weights that foUows the Anderson-Shulz-Flory model. The distribution is described by a linear relationship between the logarithm of product yield vs carbon number. The objective of much of the development work on the FT synthesis has been to circumvent the theoretical distribution so as to increase the yields of gasoline range hydrocarbons. 

In order to rationalize the disagreement between the model of Scheme 7.6 and observation, Polyakov developed a more computable chain/block length distribution model to treat the continuum from a living polymerization (Poisson distribution) to a terminating polymerization (Shulz-Flory distribution... 

In these first studies the samples were very polydisperse M /Mn = 5 to 8, and the discussion of the physical properties such as the internal conformation of the chain or the threshold for the gel formation were made without considering the polydispersity effect The molecular weight and mass distribution depends drastically from the way the sample is prepared. Because the polymer grows in monomer single crystal, a Shulz-Flory distribution does not necessarily occur. The size and the polydispersity are very... 

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