Molecular weight of a chain

It is apparent from these reactions how chain transfer lowers the molecular weight of a chain-growth polymer. The effect of chain transfer on the rate of polymerization depends on the rate at which the new radicals reinitiate polymerization ... 

To give an example of reduced activity of PVGs, papers [45, 46] can be mentioned where hydrodynamic properties of the products of bulk copolymerization of styrene with 0.4% DVB (without removing the inhibitor ieri-butylcatechol) have been examined. If the copolymerization was ideal, one DVB molecule, surrounded by 250 styrene units, would form a tetrafunctional branching point in the macromolecule and the molecular weight of a chain between two branching points should be as high as... 

If the molecular weight of a chain strand between two cross-links is M, ... 

Then, they defined Mg (which they also linked with the plateau modulus Gjv according to Eq. (13.2) as described below) as the molecular weight of a chain at which Ngp = 2, that is, when there is just one other chain in the sparmed volume. Since Vsp is proportional to a at M = Mg, the argument naturally leads to an equation equivalent to Elq. (13.4), disregarding the difference in the proportional constant. The arbitrariness of setting Ngp = 2 at M = Mg is absorbed in the proportional constant as well. Fetters et al. started by setting Ngp equal to 2 at the onset of entanglement, which they assumed to be Mg, and then they moved on to link this Mg with the plateau... 

Where A/ is molecular weight of a chain part between entanglements traditional nodes ( binary hookings ), which is equal to 1390 g/mole for low-density polyethylenes [17]. 

Figure 1.33 The dependence of the front-factor A value on molecular weight of a chain part between clusters for (1) LDPE and (2) HDPE [57]...

The rate at which the molecular weight of a chain-growth polymerization increases d >ends on three rates the rate of initiation, propagation, and termination (Ri, Rp, Rt). In many cases, once initiated, the pol)rmerization proceeds very quickly, and foe... 

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