Length, number average

Instantaneous number average styrene sequence length Number average styrene sequence length... 

Fibre length number average (mm) Fibres longer than 0.2 mm (%) Notched Izod impact strength (kj m- )... 

The inlet monomer concentration was varied sinusoidally to determine the effect of these changes on Dp, the time-averaged polydispersity, when compared with the steady-state case. For the unsteady state CSTR, the pseudo steady-state assumption for active centres was used to simplify computations. In both of the mechanisms considered, D increases with respect to the steady-state value (for constant conversion and number average chain length y ) as the frequency of the oscillation in the monomer feed concentration is decreased. The maximum deviation in D thus occurs as lo 0. However, it was predicted that the value of D could only be increased by 10-325S with respect to the steady state depending on reaction mechanism and the amplitude of the oscillating feed. Laurence and Vasudevan (12) considered a reaction with combination termination and no chain transfer. 

If the reaction goes to completion, the polymer molecules will have the form B B, and the final concentration of B endgroups will be [B]o-[A]q. The number average chain length is... 

TABLE 13 1 Number Average Chain Lengths for Binary Polycondensations Going to Completion... 

The ratio of weight-to-number average chain lengths is the polydispersity,... 

The dynamic chain length is the number average length of the growing chains before termination. The dead polymer will have the same average length as live polymer if termination is by disproportionation and will have twice this length if termination is by combination. 

FIGURE 13.5 Representative profiles of viscosity versus conversion for free-radical and condensation polymerizations. The endpoint is 99.9% conversion with a number average chain length of 1000. 

A binary polycondensation of AMA and BNB is to be performed in a batch reactor. A number average chain length of at least 100 is required. What minimum accuracy is required for weighing the two components ... 

Calculation of the N.A.S.L. (Number Average Sequence Length) can be performed, according to the definition given by Randall, given the model probabilities. Generation of the coefficients used in the equation required for this option, however, has not been automated. 

Number-Average Chain Length of the Primary Molecules which Belong to the Gel Fraction. 

The detector response ratio is elevated with respect to the homopolymer line but very near parallel to it less than = 0.74,or number average styrene sequence lengths less... 

Ln is the number average contour length from the EM data... 

In the absence of any transfer, only the type of termination reaction has to be taken into account to obtain the number average degree of polymerisation (or chain length) Xn. Indeed, if the reaction terminates by addition, two radicals give one chain, while if the reaction terminates by disproportionation, one radical generates one chain. Using 0.5 < x < 1, one obtains... 

---