Variation of molecular weight

Figure 11. Variation of molecular weight between cross-links as a function of molecular weight...

Tomlinson MR, Genzer J (2003) Eormation of grafted macromolecular assemblies with a gradual variation of molecular weight on soUd substrates. Macromolecules 36 3449-3451... 

Fig. l-l Variation of molecular weight with conversion (a) chain polymerization (b) step polymerization (c) nonterminating chain polymerization and protein synthesis. 

Clearly, much more information is needed about the behaviour of these two monomers and oxacyclobutane is perhaps the more favorable for further study because of its clearer catalyst-co-catalyst relationship and the absence of vinyl ether formation. The particular information needed about oxacyclobutane reactions at the present time are (a) knowledge of the fate of the catalyst, (b) viscosity-molecular weight relationship, (c) much more information about the variation of molecular weight with the reaction variables, and (d) information about the reaction of both monomer and polymer with oxonium ions and about the ease of formation of oxonium ions by oxacyclobutane. 

It is clear that the effects of other differences between samples far outweigh any effect that variation of molecular weight may have. 

Effect of Variation of Molecular Weight of Polwinyl Alcohol... 

Her N., Amy G., Foss D., and Cho J. (2002) Variations of molecular weight estimation by HP-Size Exclusion Chromatography with UVA versus online DOC detection. Environ. Set Technol. 36, 3393—3399. 

The above classification of polymers according to polymerization mechanism, as shown by the variation of molecular weight with conversion [Figs. 1.2(a) and 1.2(b)], is not without its ambiguities. Certain polymerizations show a linear increase of molecular weight with conversion [Fig. 1.2(c)] when the polymerization mechanism deviates from the normal chain or step pathway. This is observed in certain ionic chain polymerizations, which involve a fast initiation process coupled with the absence of reactions that terminate the propagating reactive centers. Biological syntheses of proteins also show the behavior described by Fig. 1.2(c) because the various... 

Figure 1.2 Variation of molecular weight with conversion in (a) step polymerization, (b) free-radical chain polymerization, and (c) ionic chain polymerization.. (Adapted from Odian, 1991.)...

Figure 2. Variation of molecular weight of the products formed by the reactions of (NPCl2) and (NPF 2) with phenyllithium, showing the relationship between halogen substitution and...

The space-time yield (column 5) reaches a maximum at about 4 1./ hour/g. cobalt. In column 6 the space-time yield was calculated as indicated in the footnote. The volume change upon reaction to form chiefly hydrocarbons with 5 to 16 carbon atoms is approximately constant over a wide range of variation of molecular weight distribution therefore the partial pressure of the reaction products is approximately directly proportional to the contraction. The figures in column 6 increase more slowly than those of column 5 with increasing throughput, but there is no maximum. It seems probable that the temperature of the catalyst surface increases... 

Figure 9 Variation of molecular weight with conversion for chain-growth vs. step-growth pol)unerization mechanisms.

The (1) color, (2) unusual melting point characteristics, (3) facile formation of pale yellow solutions (in organic solvents) which were rapidly decolorized in the presence of sunlight, (4) variation of molecular weights... 

FIGURE 1 Variation of molecular weight with % conversion for (A) step-growth polymerization, (B) chain-growth polymerization, and (C) living chain-growth polymerization with no chain transfer and no chain termination. 

This hypothesis was experimentally confirmed by following the variation of molecular weight of the reaction products in time. Figure 3.232. 

Limited influence to molecular weight and Great variation of molecular weight and... 

Chloroprene is very reactive and can be polymerized with elemental sulfur. The resulting block copolymer consists of chloroprene and sulfur segments of various lengths. The sulfur can either be dissolved in the liquid monomer or added as a dispersion. The sulfur bridges are easily cleaved by iodoform or other additives, thus permitting a variation of molecular weights over a wide range [297]. 

Chu K-J, Soares IBP, Penlidis A (2000) Variation of molecular weight distribution (MWD) and short chain branching distribution (SCBD) of ethylene/1-hexene copolymers produced with different in-situ supported metallocene catalysts. Macromol Chem Phys 201 340-348... 

Not all publications give information about the caUbrafion standard for the SEC-analysis. The table shows a strong variation of molecular weights and PDIs, even with identical monomers. This is due to different catalysts being applied for the polymerization and will be discussed in the following section. 

According to Geletsyan and co-workers [25], data on consumption of radicals during polychloroprene mastication must be considered with care. This is because acceptors only reactive with radicals having a free valency on a carbon atom can also, under certain conditions, interact with other active polymer sites. In this case, agreement is not observed between variations of molecular weight and radical consumption. 

Fig. 7 Flocculation curves for excess sludge with Sedipur products (Al, A2, A3) variation of molecular weight of Ae flocculants...

Figure 1.1 Variation of molecular weight with time during addition polymerization.

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