Polystyrene anionic

Chromate Anion Polystyrene matrix Tertiary or quaternary ammonium functional groups Sodium carbonate or alkaline NaCl... 

Nitrate Anion Polystyrene matrix Trihiityl ammonium functional group Nad... 

Polystyrene-polytetrahydrofuran block copolymers121122 are an interesting case of coupling between functional polymers The mutual deactivation of living anionic polystyrene and living cationic polyoxolane occurs quantitatively to yield polystyrene-polyoxolane block copolymers. Since either of the initial polymer species can be mono- or difunctional, diblock, triblock or multiblock copolymers can be obtained. 

Figure 7.6 Preparation of triblock hybrid from two-ended anionic polystyrene...

Another way of synthesizing block copolyers it to have two polymers which possess mutually reacting chain ends. A picturesque example is the mutual deactivation of living" cationic polytetrahydrofuran and of "living" anionic polystyrene.12... 

To complete this previous work, it was interesting to study in detail the reaction between AIBN and a living anionic polystyrene, for monofunctional polystyrene I Me as well as for difunctional polystyrene M t Me . 

The living anionic polystyrene are prepared according to actually well known techniques (T U). The initiation is achieved... 

TABLE 1 Coupling efficiency p as a function of the counter-ion Me and the end group carbanion of the living anionic polystyrene. System monofunctional P > + AIBN... 

Thus, the reaction of living anionic polystyrene with AIBN, leading to chain coupling with elimination of CN , seems to be similar to that proposed by YOSHIMURA (15) for the reaction of carbanions with substituted a aminonitriles. 

PSI anionic polystyrene with isopren / terminal units... 

PSDPK anionic polystyrene with cl iphony 1 thy 1 terminal unit... 

PSMMA anionic polystyrene with me thy l mo t line ry I y terminal unit... 

Onogi,S., Masuda,T., Kitagawa,K. Rheological properties of anionic polystyrenes. 

Onogi,S., Masuda,T., Kitagawa,K. Rheological properties of anionic polystyrenes. I. Dynamic viscoelasticity of narrow-distribution polystyrenes. Macromolecules 3, 109-116 (1970). 

Fig. 1.2. Extinction angles % vs. shear rate q for a 2 wt. per cent solution of anionic polystyrene Sill in methyl 4-bromo-phenyl carbinol at the indicated temperatures...

Fig. 2.4. Doubled extinction angle 2% vs. shear rate (open circles) and loss angle <5 vs. angular frequency (closed circles) for the melt of anionic polystyrene Sill at a measurement temperature of 196° C [Wales, Den Otter (56)]...

Anionic polystyrene Sill seems to be a suitable polymer for this type of investigation. Some solution properties of this polymer have already been discussed in the previous chapter. Fig. 2.4 gives some properties of the melt of this polymer at a measurement temperature of 196° C (56). In this figure the doubled extinction angle 2% as a function of shear rate q (open circles) is compared with the loss angle d as a function of angular frequency (closed circles). In accordance with eq. (2.22) the initial slopes of these curves coincide. This coincidence, however, appears to persist even into the non-linear part of the functions. Such a persistence... 

Table 3.2. Data of investigated anionic polystyrenes and of solvents used...

Measurements on solutions of anionic polystyrenes gave more promising results 34, 70). Apparently, these polymers possess narrower molecular weight distributions than the best fractions quoted in Tsvetkov s review. 

In Fig. 3.1 results according to ref. 70 axe shown. These results, which are plotted on a double logarithmic scale, according to eq. (3.41a), were obtained on solutions of three anionic polystyrenes in monobromo-benzene at 25° C. Some data of these polymers, which were provided by J. Altares of Mellon Institute, are given in Table 3.2 together with data of the well-known semi-technical sample Sill. 

Fig. 3.1. Reduced stored free energy Fs vs. reduced shear rate py for three samples of anionic polystyrene in monobromo-benzene at 25° C 70). Data of these samples are gathered in Table 3.2. The following concentrations given in g/100 cm8, are used Taps. No. 5 ( -) 0.50, (- ) 0.35, (J) 0.20, (1) 0.10 Taps. No. 17 (o-) 1.00, (-O) 0.50, () 0.35, (i) 0.20 Taps. No. 15 (4) 1.00, (It) 0.633, (. ) 0.40. "F" indicates free-draining, N non-draining limit according to Zimm (SO). For the meaning of the broken lines see Section 5.3.2...

The fact that the measured points of Fig. 3.1 lie more closely to the free-draining line, is in accordance with the experience obtained on anionic polystyrenes with other measuring techniques [dynamic oscillatory measurements (115), measurements of normal stresses (776)]. This result is quite surprising since for the description of intrinsic viscosity the non-draining case has clearly been shown to be valid (100). It will be shown below and in Chapter 4 that this inconsistency is in reality a consequence of the fact that the reduction with respect to concentration is less perfect than one would think at a first inspection of Fig. 3.1. 

Possible other reasons for a too high value of the reduced steady-state compliance, when compared with the expected non-draining value, are given by the facts that bromo-benzene is a very good solvent and that even the anionic polystyrenes have no completely uniform molecular weight. The second point will be treated in Section 3.8.3. As to the first point, it can be shown by experiment that the excluded volume... 

At this point it seems of interest to include a graph obtained on a quite different polymer, viz. cellulose tricarbanilate. Results from a series of ten sharp fractions of this polymer will be discussed in Chapter 5 in connection with the limits of validity of the present theory. In Fig. 3.5 a double logarithmic plot of FR vs. is given for a molecular weight of 720000. This figure refers to a 0.1 wt. per cent solution in benzophenone. It appears that the temperature reduction is perfect. Moreover, the JeR-value for fiN smaller than one is very close to the JeR value obtained from Figure 3.1 for anionic polystyrenes in bromo-benzene. As in the case of Fig. 3.1, pN is calculated from zero shear viscosity. The correspondence of Figs. 3.1 and 3.5 shows that also the molecules of cellulose tricarbanilate behave like flexible linear chain molecules. For more details on this subject reference is made to Chapter 5. 

The introductory considerations of the previous section were induced by interesting experimental results obtained by Daum (32), who investigated the best way of extrapolating results to zero concentration. From this work and some recent results of Wales (59) on polymer melts, Fig. 4.4 is constructed. This figure shows the concentration dependence of reduced steady-state compliance JeR for a series of anionic polystyrenes. The molecular weights of these polymers are given in Table 4.1. For a specification of the solutions see the caption to Fig. 4.4. 

Fig. 4.4. Concentration dependence of reduced steady-state shear compliance J,B for a series of anionic polystyrenes, as mostly provided by Pressure Chem. Corp., Pittsburgh, Pa. Except for the solutions of the three lowest concentrations of S 111 (Dow Chem. Corp.), which were prepared with methyl (4-bromo-phenyl) carbinol and used at various temperatures, all solutions were prepared with mono-bromo-benzene and used at 25° C (32). Measurement temperatures for the melts varied from 196 to 240° C (59). For the molecular weights of the polymers see Table 4.1...

Table 4.1. Molecular weights of anionic polystyrenes used for Fig. 4.4...

Kuhn for statistically coiled molecules. The two dotted lines denoted by F and N stand for the free-draining and the non-draining case of Zimm s theoty for Gaussian coils. The hatched area indicates the area where the experimental points obtained on solutions of anionic polystyrenes are located (See Fig. 3.1). 

Fig. 5.8. Cotangent of the doubled extinction angle (corrected for solvent birefringence) vs. reduced shear rate f s for a series of cellulose tricarbanilate fractions in benzophenone at 55° C (772). Broken and dotted lines are explained in the text. Hatched area indicates location of experimental results on anionic polystyrenes. Molecular weights of cellulose tricarbanilate fractions () 27000, (f) 38000, (A) 57000, (a) 90000, (o) 152,000, ( ) 280,000, (o) 500,000, ( ) 720,000 and...

For these measurements, temperature has been varied between 55 and 110° C. In this temperature range, the solvent viscosity changes by a factor three 4.7 to 1.5 cps). It is very improbable that a noticeable internal friction factor would change just by the same factor. Moreover, as has already been pointed out at the end of Section 5.2.2, the curves obtained by plotting cot2 c vs reduced shear stress fjN are practically coinciding for dilute solutions of cellulose tricarbanilate fractions with M S 500,000 and for anionic polystyrenes. So one can conclude that the internal friction of the thermodynamically stiff molecules of cellulose tricarbanilate must be rather low. 

At this point, it should be reminded that the results obtained on solutions of anionic polystyrenes and reported in Section 3.8.2, are also in accordance with the unmodified theory of Zimm. This means that, even in the low viscous solvent monobromo-benzene, the molecules of polystyrene do not show a measurable effect of internal friction. According to Cerf [eqs. (5.27) or (5.31a)] one should preferably choose polymer samples of not too high molecular weights, in order to evaluate kinetic... 

The summative-fractioruition method was extended to apply to narrow-distribution polymers with polydispersity (Mw/ Mn) less than 1.12. A fractionation parameter H, previously defined and calculated for theoretical molecular weight distributions for normal polymers, was computed for narrow-distribution polymers. The calculations were made both with and without correction for fractionation errors, using the Flory-Huggins treatment. The method was applied to a well-characterized anionic polystyrene with Mw = 97,000, for which the polydispersity was estimated by this technique to be 1.02 (in the range 1.014-1.027, 95% confidence limits). 

Fig. 22a and b. Dependence of the measured elution volume V = VD (in cm3, Fig. a), and of the standard deviation ctd (in cm3), skewness yD, and kurtosis 5D (Fig. b) on the weight-average of the polymerization degree Pw of very narrowly distributed polystyrene samples (BW-middle fractions of the anionic polystyrene standards), injected into the PDC-column 3) at 28 °C where the resolution of the column can be neglected in the Pw-range as indicated (polystyrene/cyclohexane, theta temperature 34 °C)... 

This can well be seen from Fig. 24 showing three measured PDC-elution curves of the same standard anionic polystyrene PCC K-l 10000 (Pw = 1080) at 23 °C (very narrow), 17 °C (medium broad) and 15 °C (very broad). Only the very broad elution curve at 15 °C allows a simple caclulation of the MWD by means of the strip method S , because only 8% of the curve-width is caused by spreading and 92% by resolution (crD/cr = 0.08), whereas the inversion method G or K described above must be applied when the MWD is calculated from the elution curve 17 °C or even 23 °C, where 73 % of the curve-width is caused by spreading and only 27 %... 

Fig. 24. PDC-elution curves D(V) of standard anionic polystyrene PCC K-l 10,000 (Pw = 1080) measured at three column temperatures, as indicated...

The solutions from a sample of anionic polystyrene (courtesy of BASF, Ludwigshafen) and the solvent were prepared by weighing. Polystyrene is characterized by the data in Table I. [The average molecular weights were determined in the Central Laboratory of the N.V. Staats-mijnen/DSM (Geleen, The Netherlands).]... 

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