- Email: [email protected]
Flow birefringence of polydimethyl- and polydiphenylsiltrimethylene solutions
1162
M. M. KUSAKOV et al.
18. Yu. Ya. GOTLIB, Fiz. tverdogo tela 6: 2938, 1964 19. Yu. Ya. GOTLIB and A. A. DARINSKII, Vysokomol. soyed. 7: 1737, 1965 20. T. M. BIRSHTEIN, Yu. Ya. GOTLIR and F. P. GRIGOR'EVA, Tezisy dokl. X I I I Konf. inst. vysokomol, soyed. Akad. N a u k SSSR, p. 25, 1966 21. Yu. Ya. GOTLIB and F. P. GRIGOR'EVA, Vysokomol. soyed. A10: 339, 1968 22. R. M. FUOSS, J. Am. Chem. Soc. 63: 378, 1941 23. G. P. MIKHAILOV, A. M. LOBANOV and D. M. MIRKAMILOV, Vysokomo]. soyed. 8: 1351, 1966 24. P. F. VESELOVSKH and V. K. MATVEYEV, Vysokomol. soyed. 6: 1221, 1964 25. G. P. MIKHAILOV, A. M. LOBANOV and D. M. MIRKAMILOV, Vysokomol. soyed. A1O: 826, 1968 26. P. F. VESELOVSKH and I. A. GANDEL'MAN, T r u d y Leningrad. politekh, inst. ira. M. I. Kalinina, No. 255, 148, 1965 27. G. P. MIKHAILOV, T . I . BORISOVA and A. S. NIGMANKHODZHAYEV, Vysokomol. soyed. 8: 991, 1966 28. F. BUECHE, J. Chem. Phys. 21: 1850, 1953 29. Yu. Ya. GOTLIB, Internat. Symp. Macromol. Chem., p. 441, Prague 1965 30. G. P. MIKHAILOV and T. I. BORISOVA, Vysokomol. soyed. 2: 619, 1960 31. T. I. BORISOVA, L. L. BURSHTEIN and G. P. MIKHAILOV, Vysokomol. soyed. 4: 1479, 1962
FLOW BIREFRINGENCE OF POLYDIMETHYLAND POLYDIPHENYLSILTRIMETHYLENE SOLUTIONS* M. M. Kvs~xov, L. I. 1V~EKEN~ITSKAYAand N. 1~I. LUBMAN Petrochemical! Synthesis Institute, U.S.S.R. A c a d e m y of Sciences (Received 19 March 1968)
AN EXRLIER communication [1] gave the results of study of the optical anisotropy and shape of the polydimethylsilmethylene macromolecule based on the dynamic birefringence changes. This paper reports the results obtained in the flow birefringence study of polydimethylsil-(PDMST~I) and polydiphenylsil- (PDPST!~) trimethylene solutions; their macromolecules differ from those studied earlier in the main chain structure and in the type of the substituent present on the Si-atom. B o t h the polymers were produced [2] b y thermal polymerization without a catalyst. (The authors wish to t h a n k N. S. Nametkin, V. M. Vdovin and V. I. Zav'yalov, for supplying the polymer samples). The polymers were examined in the unfractioned state in various solvents. The physical properties of both the polymers are contained in Table 1. The mol. wt. was determined b y the light-scattering method [3], the density b y p y k n o m e t r y , and the refractive index b y the immersion method. The intrinsic viscosity was measured b y using a 4-ball capillary viscometer and then calculating the value b y extrapolating to a zero * Vysokomol. soyed. A l l : No. 5, 1028-1032, 1969.
Flow birefringence of PDMSTM and PDPSTM solutions
1163
flow gradient. A dynamo-optimeter described earlier [1, 4] was used to determine the birefringence. All the measurements were carried out at 25°C. The solutions were first filtered and centrifuged. TABLE
1. P H Y S I C A L
PROPEICtTIES O F T H E P O L Y M E R S
iv.
weight Density, Refract. index, tool. wt.. p~S, ,M,,,× 10_, I g/cm3
Polymer
Intrinsic viscosity, [~/]o× 10-~, em3/g, in tol- bromo- CC14 heptuene form ~ne I
[ -- (CHa)2Si(CH2)an - ] ---[-- (C,H~hSi(CH,h~--]--
-
0.30 1.80
0.932 1.090
1.506 1.588
2.8 3.1
4.5
3.0
3.6
. P D M S T M . The dynamo-optical and molecular characteristic of PDSISTSI, determined on toulene and heptane solutions, are given i n Table 2. The anisotropy of these polymer macromolecules was characterized on the basis of dynamic birefringence (An) and viscosity (y) of toluene and carbon tetrachloride solutions. Owing to the similarity of the reactive indices of the polymer solution (nk) and toluene, the solvent, or CC14 (n~), the anisotropy of the latter characterized the effect of intrinsic anisotropy. The diagram of An---= f[g(t/--t/0)] was plotted taking into acoount y = f ( g ) and An of the solvent for different solution concentrations in toluene and CC14 (Fig. la); it shows the reduced viscosity [An/g(tl--tlo)]g_+o in each of the solvents to be independent of concentration within the limits of experimental error. The K u h n formula was used, following the conditions of Peterlin, to determine (~1--a2) for the segmental anisotropy of PDMSTM macromolecules. It can be assumed that the more probable a1--~2 value for P D M S T ~ will be that determined in CC14, which has a lower polarization capacity than toluene, and is a non-polar solvent. (a1--~2)=25 X10 -25 cm a and (atL--a±)=5 X10 -~5 cm a in CCI4. Value S, the number of monomer units per segment, which characterizes the flexibility of the PDMSTI~I macromolecules, was determined from the ratio of the 0-dimension v~wJ0/~½ ~2to (h02)t for a free rotation model, in which the 0-dimension, according to theory [7-9], is calculated from the light-scattering d a t a [3] in a "good" solvent. The S-value was used to calculate the anisotropy of the monomer unit, all--a ± . The asymmetry of shape (shape factor R) of the molecular coil and the Flory factor (4) was determined b y calculating the shape from the flow birefringence of different PDMSTI~I concentrations in heptane. The intrinsic birefringence [hi in this solvent, for which nk#n~, was the sum of two effects, i.e. the intrinsic anisotropy and the shape effect [10]. [n] in heptane was determined
[n]
from [An/g(rl--~lo)g.~o-=r-~
, which was obtained b y extrapolating to zero con-
centration the plot of function [An/g(tl--tlo)]g~o=-f(c).
1164
M.M. KVSAK0V et al.
The calculated R- and ~-values, together with S, characterize the PD~ISTM molecules as linear, flexible macromolecules. PDPSTM. The characteristics of P D P S T h l are also contained in Table 2; T A B L E 2. D Y N A M O - O P T I C A L AND MOLECULAR CHARACTERSTICS OF P D M S T M AND PDPSTI~I
Polymer
X
X ~,
,,
x
x
cm. see2/g 3"0 5'4 --[-- (CHa)sSi (CHs)a--]a ---[-- C6Hs)2Si(CI-I2)3--]n-- --4.0 11.3
;~
2'5 Noeffectl 37 6"0 9.0 /--50
5 22
-- 7-4 2"3 2"5 2.4
X O
2"5 2"3
t h e y were determined in bromoform and toluene as solvents. The birefringence in bromoform, due to the intrinsic anisotropy of the P D P S T ~ molecules, was negative, as expected [11]. Figure lb shows A n (taking into account t h a t of bromoform) as a function of shear stress g (~/--g0) (the viscosities of the respective solutions corresponded with the applied flow rate gradient), using different concentrations, a n d this value was used to calculate (al--a2).
/in, 108 a ~I
1"6
o2o3
e4~ e 5
b
/ el
O
a, 2
e3
0"8
~I~1
O
~
I
18
I
I
32
I
I
#8
I
I
I
6# g(q-qo),g.cm-~.s~-2
8
18
N ,9, sec-~
Fic. 1. Birefringence (zi n) as a function of shear stress for solutions of different concentration: a--PDMST~¢I in toluene (1, 2) and in CC14 (3-5). Concentrations as g/100 mh 1--0-24, 2--0.5, 3--0.14, 4--0.35, 5--0.51; b--PDPSTS~ in bromoform (g/100 ml): •--0.20, 2--0.29, 3--0.40. I t was discovered during the determination of the birefringence a n d viscosities of toluene solutions t h a t the former changed in sign from negative to positive, regardless of the relatively small difference n k - - n , ; this indicates t h a t
F l o w b i r e f r i n g e n c e of P D M S T M a n d P D P S T M s o l u t i o n s
1165
the shape has a considerable effect. The plotting of the reduced anisotropy of the toluene solution against concentration gave curve I in Fig. 2, while t h a t Lln
12
8 8 !
0 -2 2
-6
F l a . 2. R e d u c e d a n i s o t r o p y •g (7/--~.)
I
02
e~0
i,
~O
I
0"6
O~q//O0~3 as a f u n c t i o n of t h e c o n c e n t r a t i o n of P D P S T M
solutions: 1--in toluene, 2--in bromoform.
of bromoform solutions is given as curve (line) 2. The extrapolation of curve 1 to c ->0 gives value [An/g(7--~o)]g.~o~c-~0 [[n] - ~ which determines the total anisotropy. If one starts from the difference between reduced total and intrinsic aniso-
[hi
tropy, [7]
[n]~ [7]
15 ×10 -10, being only the reduced macro-shape anisotropy~
the shape effect will be [n]/-~46 ×10 -s, while ¢~-5.6 ×10 ~a mole -1. Such a large Flory factor is evidence that not all the difference between the total anisotropy and the intrinsic is due to the coil shape alone. It seems that the micro-shape also plays a part [11]. Returning once more to curve 1 in Fig. 2, we can see that the reduced anisotropy of the solution does not change any more after a certain concentration; this is typical for the presence of a micro-shape effect (segmental anisotropy of shape). The reduced segmental shape anisotropy can be determined from the ordinate difference between the parts parallel to the abscissa of curves 1 and 2, converted for toluene, in Fig. 2. The consideration of the micro-shape effect, when calculating the Flory factor, gives a value which agrees well with the majority of data for macromolecules in good solvents (Table 2). The obtained R-value is typical for an ellipsoidal molecule.
M. lV[. K u s A x o v et
1166
al.
The existence of a micro-shape effect in the case of PDPSTI~I permitted the determination of S (the monomer unit number) in the equivalent Gaussian segment, using equation [11]:
= ( ~ + 2 ) (nk -n~) [7]
180.nRT.n~.p
M°'S'(L~--L1)8"
By taking the asymmetry factor of segmental shape (L2--L1) s to be 2n, the mol. wt. of the monomer unit M0----224, we get S~-22. Comparing this value with S = 1 5 , got from the maeromolecular dimensions calculated for 0-conditions from light-scattering in a good solvent (toluene, (~)½=2.25 ×10 -5, A~=2.8 × 10-¢ [3]), the two values are of the same order, bearing in mind the unavoidable experimental errors, and an average S-~ 19 can be accepted for P D P S T ~ . The larger S speaks of considerable rigidity of this polymer (The differing characteristic flexibilities of PDPST~I maeromolecules obtained from measurement of the 0-dimension in a mixed solvent (toluene+cyclohexanol [3]), and determined from the 0-dimension calculated from light-scattering in toluene, seem to be explained by maeromolecular conformation changes in the mixed solvent containing polar component). The analysis of the obtained S- and R-values, also taking into account those obtained by other physico-chemical study methods [2], permit the theory of P D P S T ~ macromolecules being semi-rigid ellipsoids. This conclusion and the macromolecular conformations differing from the Gaussian coil are also illustrated in Table 3 by the dimensions obtained from light-scattering, and calculated from the intrinsic viscosities according to the Flory function for polyisobutylene, its organosilicon analogue, and the macromolecules of the two • studied polymers. Both the dimensions should agree only for flexible macromolecules modelled by Gaussian coils. As Table 3 shows, the macromolecular dimensions are practically the same for the first three, but there is difference of almost 40% in the case of PDPST~I. T A B L E 3. M A C R O M O L E C U L A R
Polymer
--[--(CH,hC(CH2)--],,--* (CH2) --L -- *
-- [ -- (CH,),Si
- - [ - - (CHs)2Si (CH2)s--]n - - * - - [ - - (C6Hs)Si (CH2)3--]n -- t
DIMENSIONS
IN A G O O D
SOLVENT
2 1 (hw), × l0 s
(h2)t × lO,
from light scatering
from intrinsic visocity
2.80 3.13 0-86 2-25
2"51 2-94 0.76 1"41
* In heptane; t In toluene.
The anisotropy (%l--a±)of the P D P S T ~ monomer units is determined to a large extent by the degree of inhibition of rotation of the phenyl group branches
1167
Flow birefringonoo of PDMSTlVl and PDPSTM solutiorLs
around the valence bonds joining them to the main chain, and could give information about the size of angle ~ between the perpendicular to the phenyl ring plane and the direction of the main chain valencies. This angle can be estimated b y comparing the experimental (all--a±) value with the theoretical value calculated from the bond polarizations and the angles between them. The polarizations of all the bonds, and the angles, are unknown in our case. The angle could be assessed [12] b y comparing the experimental monomer bond anisotropy changes, A (all--a±), caused b y the substitution of two methyl groups for two phenyl groups, with the theoretical, using the tabulated data on phenyl ring polarization. The zl (all--a±) value for two rings is obtained as the difference between the (all--a±) of the monomer unit of P D P S T ~ molecule and that of P D ~ S T ~ produced experimentally. This difference was found to be 7.3 ×10 -35 cm a. Its comparison with the theoretical gives an average angle @~52 ° for the P D P S T ~ molecule. This result shows that the rotation of the phenyl groups in PDPSTI~ molecules is slightly hindered, because for free rotation the average angle ~ would be 45 °. CONCLUSIONS
(l) The molecular-optical characteristics (segmental anisotropy, monomer unit anisotropy, shape factor, Flory coefficient) were determined from the dynamic birefringence and viscosity measurements of the solutions, and also the flexibility of the PDMSTME and P D P S T ~ macromolecules. (2) The P D ~ S T ~ molecules were found to be flexible and linear. (3) The analysis of the shape factor and of the number of monomer units present in the P D P S T M segment, obtained from the micro-shape effect, forms the basis of the theory that these polymer molecules are semirigid ellipsoids. (4) The anisotropy changes of the monomer unit caused b y replacing two methyl b y two phenyl groups were used to determine the average angle between the phenyl ring plane and the direction of the main valence chain of the P D P S T ~ macromolecules; the phenyl ring rotation in the macromolecules of this polymer was found to be slightly hindered.
Translated by K.
A. ALLE~
REFERENCES 1. M. M. KUSAKOV, N. M. LUBMAN, L. I. MEKENITSKAYA and E. P. SOMOVA, Vysoko-
tool. soyed. Ag: 1666, 1967 2. N. S. NAMETKIN, V. M. VDOVIN and V. I. ZAV'YALOV, Izv. Akad. Nattk SSSR, seriya khim., 1443, 1965 3. A. Yu. KOSHEVNIK, M. M. KUSAKOV and E. A. RAZUMOVSKAYA, Vysokomol. soyed. AI0: 2795, 1968 4. M. M. KUSAKOV, N. M. LUBMAN and L. I. MEKENITSKAYA, Pribory i tekh. eksper., No. 5, 221, 1967 5. A. Ye. GRISHCHENKO, M. G. VITOVSKAYA, V. N. TSVETKOV, Ye. P. VOROB'EVA,
N. N. SAPRYKINA and L. I. MEZENTSEVA, Vysokomol. soyed. Ag: 1280, 1967
B. D. BEP~EZXN and L. P. SHO~A_WOVA
1168
E. V. FRISMAN and A. K. DADIVANYAN, Vysokomol. soyed. 8: 1359, 1966 T. OROFINO and P. FLORY, Chem. Phys. 26: 1067, 1957 O. B. PTITSYN, Dokl. Akad. Nauk SSSR 129: 165, 1959 O. B. PTITSYN and Yu. E. EISNER, Vysokomol. soyed. 1: 1200, 1959 V. N. TSVETKOV and E. V. FRISMAN, Dokl. Akad. Nauk SSSR 97: 647, 1954 V. N. TSVETKOV, V. Ye. ESKIN and S. Ira. FRENKEL', Struktura makromolekul v rastvorakh (The Structure of Macromolecules in Solution). Izd. "Nauka", 1964 12. V. N. TSVETKOV, E. V. FRISMAN and N. N. BOITS0VA, Vysokomol. soyed. 2: 1001, 1960 6. 7. 8. 9. 10. 11.
KINETIC STABILITY OF POLYPHTHALOCYANINE (PPC) COMPLEXES * B. D. BEREZlN and L. P. SHORMAI~OV/k I v a n o v Chemico-Technological I n s t i t u t e
(Received 20 March 1968)
THIS work describes the results of studying polyphthalocyanine (PPC) complexes synthesized from pyromellitic dianhydride and the phthalie anhydride [1]:
in which l~I----Zn, lqi, Cu, Ga'HSO4, OsSO4. Earlier we had shown [1] that the inclusion of the phthalocyanine bond unit in the polymer greatly changed the physical properties of the phthalocyanine complexes, such as the solubility in organic solvents, the absorption intensity, the fine structure of the infrared spectral lines, etc. *
Vysoken~ol. soyed. A l l : No. 5, 1033-1038, 1969.
M. M. KUSAKOV et al.
18. Yu. Ya. GOTLIB, Fiz. tverdogo tela 6: 2938, 1964 19. Yu. Ya. GOTLIB and A. A. DARINSKII, Vysokomol. soyed. 7: 1737, 1965 20. T. M. BIRSHTEIN, Yu. Ya. GOTLIR and F. P. GRIGOR'EVA, Tezisy dokl. X I I I Konf. inst. vysokomol, soyed. Akad. N a u k SSSR, p. 25, 1966 21. Yu. Ya. GOTLIB and F. P. GRIGOR'EVA, Vysokomol. soyed. A10: 339, 1968 22. R. M. FUOSS, J. Am. Chem. Soc. 63: 378, 1941 23. G. P. MIKHAILOV, A. M. LOBANOV and D. M. MIRKAMILOV, Vysokomo]. soyed. 8: 1351, 1966 24. P. F. VESELOVSKH and V. K. MATVEYEV, Vysokomol. soyed. 6: 1221, 1964 25. G. P. MIKHAILOV, A. M. LOBANOV and D. M. MIRKAMILOV, Vysokomol. soyed. A1O: 826, 1968 26. P. F. VESELOVSKH and I. A. GANDEL'MAN, T r u d y Leningrad. politekh, inst. ira. M. I. Kalinina, No. 255, 148, 1965 27. G. P. MIKHAILOV, T . I . BORISOVA and A. S. NIGMANKHODZHAYEV, Vysokomol. soyed. 8: 991, 1966 28. F. BUECHE, J. Chem. Phys. 21: 1850, 1953 29. Yu. Ya. GOTLIB, Internat. Symp. Macromol. Chem., p. 441, Prague 1965 30. G. P. MIKHAILOV and T. I. BORISOVA, Vysokomol. soyed. 2: 619, 1960 31. T. I. BORISOVA, L. L. BURSHTEIN and G. P. MIKHAILOV, Vysokomol. soyed. 4: 1479, 1962
FLOW BIREFRINGENCE OF POLYDIMETHYLAND POLYDIPHENYLSILTRIMETHYLENE SOLUTIONS* M. M. Kvs~xov, L. I. 1V~EKEN~ITSKAYAand N. 1~I. LUBMAN Petrochemical! Synthesis Institute, U.S.S.R. A c a d e m y of Sciences (Received 19 March 1968)
AN EXRLIER communication [1] gave the results of study of the optical anisotropy and shape of the polydimethylsilmethylene macromolecule based on the dynamic birefringence changes. This paper reports the results obtained in the flow birefringence study of polydimethylsil-(PDMST~I) and polydiphenylsil- (PDPST!~) trimethylene solutions; their macromolecules differ from those studied earlier in the main chain structure and in the type of the substituent present on the Si-atom. B o t h the polymers were produced [2] b y thermal polymerization without a catalyst. (The authors wish to t h a n k N. S. Nametkin, V. M. Vdovin and V. I. Zav'yalov, for supplying the polymer samples). The polymers were examined in the unfractioned state in various solvents. The physical properties of both the polymers are contained in Table 1. The mol. wt. was determined b y the light-scattering method [3], the density b y p y k n o m e t r y , and the refractive index b y the immersion method. The intrinsic viscosity was measured b y using a 4-ball capillary viscometer and then calculating the value b y extrapolating to a zero * Vysokomol. soyed. A l l : No. 5, 1028-1032, 1969.
Flow birefringence of PDMSTM and PDPSTM solutions
1163
flow gradient. A dynamo-optimeter described earlier [1, 4] was used to determine the birefringence. All the measurements were carried out at 25°C. The solutions were first filtered and centrifuged. TABLE
1. P H Y S I C A L
PROPEICtTIES O F T H E P O L Y M E R S
iv.
weight Density, Refract. index, tool. wt.. p~S, ,M,,,× 10_, I g/cm3
Polymer
Intrinsic viscosity, [~/]o× 10-~, em3/g, in tol- bromo- CC14 heptuene form ~ne I
[ -- (CHa)2Si(CH2)an - ] ---[-- (C,H~hSi(CH,h~--]--
-
0.30 1.80
0.932 1.090
1.506 1.588
2.8 3.1
4.5
3.0
3.6
. P D M S T M . The dynamo-optical and molecular characteristic of PDSISTSI, determined on toulene and heptane solutions, are given i n Table 2. The anisotropy of these polymer macromolecules was characterized on the basis of dynamic birefringence (An) and viscosity (y) of toluene and carbon tetrachloride solutions. Owing to the similarity of the reactive indices of the polymer solution (nk) and toluene, the solvent, or CC14 (n~), the anisotropy of the latter characterized the effect of intrinsic anisotropy. The diagram of An---= f[g(t/--t/0)] was plotted taking into acoount y = f ( g ) and An of the solvent for different solution concentrations in toluene and CC14 (Fig. la); it shows the reduced viscosity [An/g(tl--tlo)]g_+o in each of the solvents to be independent of concentration within the limits of experimental error. The K u h n formula was used, following the conditions of Peterlin, to determine (~1--a2) for the segmental anisotropy of PDMSTM macromolecules. It can be assumed that the more probable a1--~2 value for P D M S T ~ will be that determined in CC14, which has a lower polarization capacity than toluene, and is a non-polar solvent. (a1--~2)=25 X10 -25 cm a and (atL--a±)=5 X10 -~5 cm a in CCI4. Value S, the number of monomer units per segment, which characterizes the flexibility of the PDMSTI~I macromolecules, was determined from the ratio of the 0-dimension v~wJ0/~½ ~2to (h02)t for a free rotation model, in which the 0-dimension, according to theory [7-9], is calculated from the light-scattering d a t a [3] in a "good" solvent. The S-value was used to calculate the anisotropy of the monomer unit, all--a ± . The asymmetry of shape (shape factor R) of the molecular coil and the Flory factor (4) was determined b y calculating the shape from the flow birefringence of different PDMSTI~I concentrations in heptane. The intrinsic birefringence [hi in this solvent, for which nk#n~, was the sum of two effects, i.e. the intrinsic anisotropy and the shape effect [10]. [n] in heptane was determined
[n]
from [An/g(rl--~lo)g.~o-=r-~
, which was obtained b y extrapolating to zero con-
centration the plot of function [An/g(tl--tlo)]g~o=-f(c).
1164
M.M. KVSAK0V et al.
The calculated R- and ~-values, together with S, characterize the PD~ISTM molecules as linear, flexible macromolecules. PDPSTM. The characteristics of P D P S T h l are also contained in Table 2; T A B L E 2. D Y N A M O - O P T I C A L AND MOLECULAR CHARACTERSTICS OF P D M S T M AND PDPSTI~I
Polymer
X
X ~,
,,
x
x
cm. see2/g 3"0 5'4 --[-- (CHa)sSi (CHs)a--]a ---[-- C6Hs)2Si(CI-I2)3--]n-- --4.0 11.3
;~
2'5 Noeffectl 37 6"0 9.0 /--50
5 22
-- 7-4 2"3 2"5 2.4
X O
2"5 2"3
t h e y were determined in bromoform and toluene as solvents. The birefringence in bromoform, due to the intrinsic anisotropy of the P D P S T ~ molecules, was negative, as expected [11]. Figure lb shows A n (taking into account t h a t of bromoform) as a function of shear stress g (~/--g0) (the viscosities of the respective solutions corresponded with the applied flow rate gradient), using different concentrations, a n d this value was used to calculate (al--a2).
/in, 108 a ~I
1"6
o2o3
e4~ e 5
b
/ el
O
a, 2
e3
0"8
~I~1
O
~
I
18
I
I
32
I
I
#8
I
I
I
6# g(q-qo),g.cm-~.s~-2
8
18
N ,9, sec-~
Fic. 1. Birefringence (zi n) as a function of shear stress for solutions of different concentration: a--PDMST~¢I in toluene (1, 2) and in CC14 (3-5). Concentrations as g/100 mh 1--0-24, 2--0.5, 3--0.14, 4--0.35, 5--0.51; b--PDPSTS~ in bromoform (g/100 ml): •--0.20, 2--0.29, 3--0.40. I t was discovered during the determination of the birefringence a n d viscosities of toluene solutions t h a t the former changed in sign from negative to positive, regardless of the relatively small difference n k - - n , ; this indicates t h a t
F l o w b i r e f r i n g e n c e of P D M S T M a n d P D P S T M s o l u t i o n s
1165
the shape has a considerable effect. The plotting of the reduced anisotropy of the toluene solution against concentration gave curve I in Fig. 2, while t h a t Lln
12
8 8 !
0 -2 2
-6
F l a . 2. R e d u c e d a n i s o t r o p y •g (7/--~.)
I
02
e~0
i,
~O
I
0"6
O~q//O0~3 as a f u n c t i o n of t h e c o n c e n t r a t i o n of P D P S T M
solutions: 1--in toluene, 2--in bromoform.
of bromoform solutions is given as curve (line) 2. The extrapolation of curve 1 to c ->0 gives value [An/g(7--~o)]g.~o~c-~0 [[n] - ~ which determines the total anisotropy. If one starts from the difference between reduced total and intrinsic aniso-
[hi
tropy, [7]
[n]~ [7]
15 ×10 -10, being only the reduced macro-shape anisotropy~
the shape effect will be [n]/-~46 ×10 -s, while ¢~-5.6 ×10 ~a mole -1. Such a large Flory factor is evidence that not all the difference between the total anisotropy and the intrinsic is due to the coil shape alone. It seems that the micro-shape also plays a part [11]. Returning once more to curve 1 in Fig. 2, we can see that the reduced anisotropy of the solution does not change any more after a certain concentration; this is typical for the presence of a micro-shape effect (segmental anisotropy of shape). The reduced segmental shape anisotropy can be determined from the ordinate difference between the parts parallel to the abscissa of curves 1 and 2, converted for toluene, in Fig. 2. The consideration of the micro-shape effect, when calculating the Flory factor, gives a value which agrees well with the majority of data for macromolecules in good solvents (Table 2). The obtained R-value is typical for an ellipsoidal molecule.
M. lV[. K u s A x o v et
1166
al.
The existence of a micro-shape effect in the case of PDPSTI~I permitted the determination of S (the monomer unit number) in the equivalent Gaussian segment, using equation [11]:
= ( ~ + 2 ) (nk -n~) [7]
180.nRT.n~.p
M°'S'(L~--L1)8"
By taking the asymmetry factor of segmental shape (L2--L1) s to be 2n, the mol. wt. of the monomer unit M0----224, we get S~-22. Comparing this value with S = 1 5 , got from the maeromolecular dimensions calculated for 0-conditions from light-scattering in a good solvent (toluene, (~)½=2.25 ×10 -5, A~=2.8 × 10-¢ [3]), the two values are of the same order, bearing in mind the unavoidable experimental errors, and an average S-~ 19 can be accepted for P D P S T ~ . The larger S speaks of considerable rigidity of this polymer (The differing characteristic flexibilities of PDPST~I maeromolecules obtained from measurement of the 0-dimension in a mixed solvent (toluene+cyclohexanol [3]), and determined from the 0-dimension calculated from light-scattering in toluene, seem to be explained by maeromolecular conformation changes in the mixed solvent containing polar component). The analysis of the obtained S- and R-values, also taking into account those obtained by other physico-chemical study methods [2], permit the theory of P D P S T ~ macromolecules being semi-rigid ellipsoids. This conclusion and the macromolecular conformations differing from the Gaussian coil are also illustrated in Table 3 by the dimensions obtained from light-scattering, and calculated from the intrinsic viscosities according to the Flory function for polyisobutylene, its organosilicon analogue, and the macromolecules of the two • studied polymers. Both the dimensions should agree only for flexible macromolecules modelled by Gaussian coils. As Table 3 shows, the macromolecular dimensions are practically the same for the first three, but there is difference of almost 40% in the case of PDPST~I. T A B L E 3. M A C R O M O L E C U L A R
Polymer
--[--(CH,hC(CH2)--],,--* (CH2) --L -- *
-- [ -- (CH,),Si
- - [ - - (CHs)2Si (CH2)s--]n - - * - - [ - - (C6Hs)Si (CH2)3--]n -- t
DIMENSIONS
IN A G O O D
SOLVENT
2 1 (hw), × l0 s
(h2)t × lO,
from light scatering
from intrinsic visocity
2.80 3.13 0-86 2-25
2"51 2-94 0.76 1"41
* In heptane; t In toluene.
The anisotropy (%l--a±)of the P D P S T ~ monomer units is determined to a large extent by the degree of inhibition of rotation of the phenyl group branches
1167
Flow birefringonoo of PDMSTlVl and PDPSTM solutiorLs
around the valence bonds joining them to the main chain, and could give information about the size of angle ~ between the perpendicular to the phenyl ring plane and the direction of the main chain valencies. This angle can be estimated b y comparing the experimental (all--a±) value with the theoretical value calculated from the bond polarizations and the angles between them. The polarizations of all the bonds, and the angles, are unknown in our case. The angle could be assessed [12] b y comparing the experimental monomer bond anisotropy changes, A (all--a±), caused b y the substitution of two methyl groups for two phenyl groups, with the theoretical, using the tabulated data on phenyl ring polarization. The zl (all--a±) value for two rings is obtained as the difference between the (all--a±) of the monomer unit of P D P S T ~ molecule and that of P D ~ S T ~ produced experimentally. This difference was found to be 7.3 ×10 -35 cm a. Its comparison with the theoretical gives an average angle @~52 ° for the P D P S T ~ molecule. This result shows that the rotation of the phenyl groups in PDPSTI~ molecules is slightly hindered, because for free rotation the average angle ~ would be 45 °. CONCLUSIONS
(l) The molecular-optical characteristics (segmental anisotropy, monomer unit anisotropy, shape factor, Flory coefficient) were determined from the dynamic birefringence and viscosity measurements of the solutions, and also the flexibility of the PDMSTME and P D P S T ~ macromolecules. (2) The P D ~ S T ~ molecules were found to be flexible and linear. (3) The analysis of the shape factor and of the number of monomer units present in the P D P S T M segment, obtained from the micro-shape effect, forms the basis of the theory that these polymer molecules are semirigid ellipsoids. (4) The anisotropy changes of the monomer unit caused b y replacing two methyl b y two phenyl groups were used to determine the average angle between the phenyl ring plane and the direction of the main valence chain of the P D P S T ~ macromolecules; the phenyl ring rotation in the macromolecules of this polymer was found to be slightly hindered.
Translated by K.
A. ALLE~
REFERENCES 1. M. M. KUSAKOV, N. M. LUBMAN, L. I. MEKENITSKAYA and E. P. SOMOVA, Vysoko-
tool. soyed. Ag: 1666, 1967 2. N. S. NAMETKIN, V. M. VDOVIN and V. I. ZAV'YALOV, Izv. Akad. Nattk SSSR, seriya khim., 1443, 1965 3. A. Yu. KOSHEVNIK, M. M. KUSAKOV and E. A. RAZUMOVSKAYA, Vysokomol. soyed. AI0: 2795, 1968 4. M. M. KUSAKOV, N. M. LUBMAN and L. I. MEKENITSKAYA, Pribory i tekh. eksper., No. 5, 221, 1967 5. A. Ye. GRISHCHENKO, M. G. VITOVSKAYA, V. N. TSVETKOV, Ye. P. VOROB'EVA,
N. N. SAPRYKINA and L. I. MEZENTSEVA, Vysokomol. soyed. Ag: 1280, 1967
B. D. BEP~EZXN and L. P. SHO~A_WOVA
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E. V. FRISMAN and A. K. DADIVANYAN, Vysokomol. soyed. 8: 1359, 1966 T. OROFINO and P. FLORY, Chem. Phys. 26: 1067, 1957 O. B. PTITSYN, Dokl. Akad. Nauk SSSR 129: 165, 1959 O. B. PTITSYN and Yu. E. EISNER, Vysokomol. soyed. 1: 1200, 1959 V. N. TSVETKOV and E. V. FRISMAN, Dokl. Akad. Nauk SSSR 97: 647, 1954 V. N. TSVETKOV, V. Ye. ESKIN and S. Ira. FRENKEL', Struktura makromolekul v rastvorakh (The Structure of Macromolecules in Solution). Izd. "Nauka", 1964 12. V. N. TSVETKOV, E. V. FRISMAN and N. N. BOITS0VA, Vysokomol. soyed. 2: 1001, 1960 6. 7. 8. 9. 10. 11.
KINETIC STABILITY OF POLYPHTHALOCYANINE (PPC) COMPLEXES * B. D. BEREZlN and L. P. SHORMAI~OV/k I v a n o v Chemico-Technological I n s t i t u t e
(Received 20 March 1968)
THIS work describes the results of studying polyphthalocyanine (PPC) complexes synthesized from pyromellitic dianhydride and the phthalie anhydride [1]:
in which l~I----Zn, lqi, Cu, Ga'HSO4, OsSO4. Earlier we had shown [1] that the inclusion of the phthalocyanine bond unit in the polymer greatly changed the physical properties of the phthalocyanine complexes, such as the solubility in organic solvents, the absorption intensity, the fine structure of the infrared spectral lines, etc. *
Vysoken~ol. soyed. A l l : No. 5, 1033-1038, 1969.