Schulz-Flory polymerization kinetics

Selectivities. Hydrocarbon selectivity data were treated to test conformance to Schulz-Flory polymerization kinetics as outlined by Henrici-Olive and Olive (7) for Fischer-Tropsch catalysis. The pertinent correlation is ... 

The production of hydrocarbons using traditional Fischer-Tropsch catalysts is governed by chain growth or polymerization kinetics. The equation describing the production of hydrocarbons, commonly referred to as the Anderson-Schulz-Flory equation, is ... 

Flory polymerization kinetics (4). Henrici-Olive and Olivd (5) proposed the use of the related equation of Schulz (6). Over the last decade the Flory equation has been used frequently to describe product distributions in FT synthesis. The Friedel-Anderson (i) or Flory (4) approaches apply when the rates of propagation and termination are independent of carbon number. We do not attempt here to discuss all previous research on FT product distributions except to say that the literature contains many examples of product distributions that obey Flory kinetics within relative narrow carbon number ranges and many that do not. 

The F-T synthesis typically follows polymerization kinetics. The Anderson-Schulz-Flory equation describes the product distribution ... 

Any mechanistic proposal must comply with the following observations. (1) The Fischer-Tropsch hydrocarbon synthesis follows the formalism of polymerization kinetics with a Schulz-Flory distribution of the molecular weights. (2) a-Olefins and alcohols occur as the primary products. (3) The aliphatic final products are formed consecutively by hydrogenation of the olefins according to " C-labeling experiments [4 f, 30 b]. (4) Chain termination processes do not deactivate the catalyst centers because the chain-growth velocity stays constant for weeks. 

A plot of In M P)/P) versus P yields a value of a from either the slope or the ordinate intercept. Agreement between the slope and intercept is used as a criterion of the soundness of Schulz-Flory fit. A typical product distribution of CO hydrogenation that reflects the polymerization kinetics is shown in Figure 7.34. 

The polycondensation processes generally produce polyamides that are mixtures of polymer molecules of different molecular weights, the distribution of which usually follows a definite continuous function according to the most probable distribution model by Schulz-Flory [3]. This distribution function may, in principle, be derived from the kinetics of polymerization process, but is more readily derived from statistical considerations. In this case, the extent... 

Different from analytical dynamic solutions, instantaneous distributions are derived to describe the polymer microstructure made at a particular instant in time during the polymerization. These distributions are snapshots of the polymer microstructure at a given moment during the polymerization. A classic instantaneous distribution used to describe the CLD of linear polyolefins and other polymers that follow analogous chain growth kinetics was developed independently by Schulz [79] and Flory [80, 81]... 

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