Polymers average defined

The correlation length in the thermosetting polymer is defined by the z-average cluster radius, which scales with conversion x as... 

Statistical polymer is defined as the averaged structure exhibiting all possible structures of polymers containing the same number of monomeric units. 

Figure 13 ROMP polymers of defined length. Varying the ratio of monomer (14) to catalyst (15) affords control over the average polymer 16 length ( ).

Viscosity-average molecular weight n (My, My). An averaged molecular weight for high polymers that relates most closely to measurements of dilute-solution viscosities of polymers. The defining equation is... 

Weight-average molecular weight (m , M ) For a sample with distributed molecular weights (all commercial polymers), the defining equation is... 

The average in (3.2.34) is taken with the distribution of the two states L and H of the empty polymer, given in Eq. (3.2.2). Here we introduce the subscript (0, 0) to stress the condition that both sites are empty to distinguish this average from the conditional average defined below. 

The average MW of the resulting polymer is defined by eqn [11], where [R2SiO]e is the equilibrium concentration of R2SiO units in linear chains, M is the MW of R2SiO unit, and [M2 ] is the concentration of terminating agent. Since equilibration is a random process, the polymer usually has the normal Flory MW distribution of The association phenomena may result in broader distribution. 

Throughout this discussion we have used the numerical fraction of molecules in a class as the weighting factor for that portion of the population. This restriction is not necessary some other weighting factor could be used equally well. As a matter of fact, one important type of average encountered in polymer chemistry is the case where the mass fraction of the ith component is used as the weighting factor. Defining the mass of material in the ith class as mj, we write... 

With this kind of information it is not difficult to evaluate the average lengths of isotactic and syndiotactic sequences in a polymer. As a step toward this objective, we define the following ... 

Hven fractionated polymer samples are generally polydisperse, which means that the molecular weight determined from intrinsic viscosity experiments is an average value. The average obtained is the viscosity average as defined by Eqs. (1.20) and (2.40) as seen by the following argument ... 

The number average degree of polymerisation x is defined as the average number of monomer units per polymer chain. Therefore if termination is by disproportionation r = jc, but if by combination r = x. 

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