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Thermodynamic affinity of oligomeric dimethylsiloxane for toluene as revealed by rayleigh light scatter and static sorption
Polymer ScienceU.S.S.R. Vol. 28, No. 12, pp. 2757-2762, 1986 Printed in Poland
0032-39J01S6 $10.00+.00 ~ 1987Pergamon Journals Ltd.
THERMODYNAMIC AFFINITY OF OLIGOMERIC DIMETHYLSILOXANE F O R T O L U E N E AS~ R E V E A L E D BY RAYLEIGH LIGHT SCATTER AND STATIC SORPTION* N. V. KORIDZE,A. A. TAGER,V. M. ANDREYEVA, L. V. ADAMOVAand S. A. NEFEDOV Gorkii Urals State University
(Received 24 April 1985) Raleigh light scatter has been used to study the general scatter and degree of depolarization of scattered light of solution of oligo-dimethylsiloxane in toluene over the whole concentration range. Static isothermal sorption of toluene vapours on the oligomer at 298 K was investigated. The concentration functions of the differences in the chemical potentials of the components zl/h and the Gibbs mixing energy A# "~ of the oligomer with toluene have been calculated in the whole range of compositions.
of Rayleigh light scatter developed by Einstein and Smolukhovskii for two-component systems establishes the link between the intensity of the scattered light on the fluctuations in concentration and the thermodynamic stability of the system expressed by a second derivative of the mean Gibbs mixing energy by composition ~92(AOm)/Ox~.For solutions of low molecular weight liquids good agreement of the values of the excess Gibbs energy gE, calculated from the data on light scatter on the fluctuations in concentration and from the vapour pressure over the solution has been demonstrated [1, 2]. For polymer solutions the possibility of calculating the thermodynamic parameters of affinity from the light scatter data has been demonstrated in two studies [3, 4]; the values of the differences in the chemical potential of the solvent A/z, and the Flory-Huggins parameter Z calculated in the region of moderately concentrated solutions satisfactorily agreed with the data of the method of equilibrium ultracentriguation [3]. The aim of the present work is to determine the Gibbs mixing energy of a polymer with solvent over the whole region of compositions by the Rayleigh light scatter method and compare the results with the method of static isothermal sorption usually employed for this purpose. T H E THEORY
Oligo-dimethylsiloxane of PMS-100 grade with 37L~=4000 was investigated. The light scatter o f the PMS solutions in toluene over the whole range of compositions was measured with the FPS-3 M nephelometer; the standard was calibrated against benzene (Rb= 16.3 x 10 -4 m -x, 2 = 546 nm) [5]. We determined the relative coefficient of total scatter Rt and the degree of depolarization o f t h e scat-
* Vysokomol. soyed. A28: No. 12, 2483-2487, 1986. 2757
N.V. KORIDZEet aL
2758
tered light Au at an angle of 90° for non-polarized incident light (2 = 546 nm) at 298 K. The refractive indices n of the solutions were measured with the IRF-23 refractometer for green light from the spectrum of a mercury lamp. For the experiments on light scatter oligomeric PMS was cleared of dust by centrifugation for 3 hr at 1.7 x 104 rpm; the quality of purification was checked against absence of asymmetry of the light scatter indicatrix. The solutions were prepared directly in the cuvette for measuring the light scatter by diluting purified PMS with dust-free toluene. The composition was expressed in gravimetric fractions of the oligomer co2. Isothermal sorption of toluene on PMS at 298 K was studied by a gravimetric method in the region of relative vapour pressure of the solvent PIPsfrom 0.07 to 0.92 using quartz spiral balances with a sensitivity 3'6 x 102 m/kg. The toluene vapour pressure was measured with the OM-2 optical manometer with graduation 0"02 Pa. The calculations of the parameters of thermodynamic affinity from the data on light scatter and static sorption were based on a programme written in FORTRAN IV language using a computer. In measuring light scatter the maximum total error [6] in the determination of Ro and A. did not exceed 3"6 and 9'4 Yorespectively and in calculating the magnitude tgz(,J#'~)/&o2 11 Yo.In the sorption experiments the error in measuring PIPs did not exceed 2"5 ~o and in calculating the magnitude Air1 4 %. Figure 1 gives for the PMS solutions in toluene the concentration functions of total scatter Rt, the degree of depolarization of the scattered light Au and the scatter on the concentration fluctuations Rc calculated from the equation [5]
Rc=Rt( 1 13 Au " ~ - R ( 6 I+--AJ
,
1
13 _~__~ ) ( 1 _ o 9 2 ) _ R 2 ( 1 6 1 ~,
13 -A~2 ,/ c o 2 , 6 l+Au2 ]
(1)
where R1 and -Rz are the coefficients o f total scatter o f light o f the components; Au~, Au2 are the degrees of depolarization of the scattered light o f toluene and PMS respectively. It shows that the curves Rt =f(c02) and Rc =f(co2) are extremal and the maxima are shifted to the region of dilute solutions ( c o ~ = 0.13). Similar dependences of excess light scatter have been obtained for PS solutions is a number of solvents [7-9]. Extremal changes in Rt with composition are also observed for mixtures of low molecular weight liquids the components of which greatly differ in the size of the molecules [10]. In the PMS-toluene systems studied the main contribution to total scatter is made by R, which indicates heavy fluctuations in concentration in the region of the extreme. The degree of depolarization of the scattered light of the solution diminishes in the region of compositions from pure toluene to co~a~ and then remains practically constant. Similar changes in Au for the mixtures benzene-methanol and chlorobenzenemethanol were found in reference [11]. T h e pattern observed in both cases is connected with the large difference in A~ of the mixed components. In the region of concentrated solutions the introduction of toluene into PMS does not significantly alter the optical anisotropy of the system and A~ remains constant to co~a~; in the region of dilute solutions the main contribution is made by anisotropic toluene which also leads to sharp rise in Au with dolution. F r o m Fig. 1 we calculated the second derivatives of the G i b b s mixing energy by composition from the equation [1 ]
a2(Ao m) 7t~RT { -
c3n ~2/,
2n . . . .
9n 2
\2
1 V--,
Thermodynamic affinity of oligomeric dimethylsiloxane~for toluene
2759
where R is the universal gas constant; T is temperature, K; 2 is the wavelength o f the incident light; -NA is the Avogadro mtmber; o is the specific volume of the solution calculated by the additive scheme. Figure 2 presents the concentration function 0 2 (Ag=)/ao922. It will be seen that the values of the derivative are positive in the whole range of compositions, the branches of the curve move to + oo and the position of the minimum along the axis of compositions corresponds to the m a x i m u m of the curve Re. The error in determination o f 02(z~gm)/&o 2 in the region of concentrated solutions rises which is due to the small values of Rc tending to zero at coz~l. Similar curves were obtained from the data on light scatter by moderately concentrated polymer solutions in references [3, 4]. Using the relation [12] a2(Ag m) 1 O(d/~) .
.
0o92
.
.
.
(3)
.
co2 &o2
/I
t80-
•
=
,/!,
120
i Rt , l O~,tn -~ 5
Au
66
3 ;
,_0.2
I 0"1";
Fie. 1
0-8 COz
I
1
0.4
I
i
o.~
t.t);,:.
FIG. 2
FIG. 1. Concentration dependence of total light scatter Rt(1), degree of depolarization ,4.(2) and scatter on concentration fluctuations Re(3) calculated from eqn. (1) of PMS solutions in toluene at 298 K. FIG. 2. Concentration dependence c32(dg")/&o~ of PMS solutions in toluene at 298 K determined, by light scatter method; maximum error of measurements shown by dot-dash line.
N . V . KORIDZEet al.
2760
f r o m the area under the curve o92aZ(Agm)/Oo92=f(og2) f r o m the Simpson f o r m u l a [13] we calculated the A/z1 values; the difference in the chemical potential o f the oligomer zl/t2 was determined f r o m the G i b b s - D u h e m equation [14] nt,~
Alt2=-f~2d(A#~),
(4)
--00
and f r o m the relation
(5)
Ag" = o91Alq + 0)2 Alz2 we calculated the Gibbs mixing energy o f polymer with solvent.
0.4
0.8 ~ z
-5
45
~/m 0"4
0"2 -8#
0.4
0.8
P/Ps F1o. 3
4g%d~,,%,kJ/kg FIG. 4
FIo. 3. Sorption isotherm of toluene vapours on PMS at 298 K. x is the equilibrium amount of sorbate vapours absorbed by weight sample of oligomer m. Fzo. 4. Concentration dependence Agm(1, 1'), A/z1 (2, 2') and A/z2(3, 3') of PMS solutions in toluene at 298 K calculated from light scatter (1-3) and sorption (1"-3') data.
Thermodynamic affinity of oligomeric dimethylsiloxane for toluene
2761
The data on the static sorption o f toluene vapours on PMS are given in Fig. 3. The sorption isotherm has the form of a curve concave to the ordinate axis o v e r the whole range of pips characteristic of elastomers [14]. F r o m these data we calculated the magnitudes A/z1 for the region of compositions from 0.98 to 0.70 of the weight fraction o f PMS f r o m the equation [14] A/~1 = R T In P/Ps
(6)
For the region of lower concentrations the A/t1 values were calculated by interpolation by the Eitken scheme [15] with a computer from a p r o g r a m m e drawn up by us. Figure 4 presents the concentration functions Apt, A/z2 and Ag m of P M S solutions in toluene calculated from eqn. (4)-(6) on the basis o f the light scatter and sorption data. In both cases the function Ag m is expressed by a curve with a minimum lying in the negative region; the values of A/A and Ap2 decrease from 0 to - o o and the curves intersect at the point of the minimum of the curve Ag m, which is in accord with the laws of thermodynamics [12]. These results show that from the experimental data on the isothermal sorption o f the vapour o f a low molecular weight liquid on a polymer in a comparatively narrow concentration region one may calculate the parameters of thermodynamic affinity over the whole concentration range. The curves A#~, Ap2 and zlgm=f(o~2) obtained from the data of the sorption method agree within the limits o f the errors of the experiment and calculation with the data of the light scatter method. These results indicate the desirability o f using the data on light scatter by polymer solutions to calculate the parameters of the thermodynamic affinity of the components.
Translated by A. CROZY
REFERENCES 1. M. F. VUKS, Rasseyaniye sveta v gazakh, zhidkostyakh i rastworakh (Light Scatter in Gases, Liquids and Solutions), 320 pp., Leningr. State Univ., Leningrad, 1977 2. D.J. COUMOU and E. L. MARKOR, Trans. Faraday Soc. 60: 1726, 1964 3. L G. SCHOLTE, Europ. Polymer J. 6: 1063, 1970 4. V. M. ANDREYEVA, A. A. TAGER, I. S. FOMINJYKH and O. L. ZAMARAYEVA, Vysokotool. soyed. A18: 286, 1976 (Translated in Polymer Sci. U.S.S.R. A18: 2, 328, 1976) 5. M. I. SHAKHPARONOV, Metody issledovaniya teplovogo dvizheniya molekul i stroyeniya zhidkostei (Methods of Investigating the Thermal Motion of Molecules and the Structure of Liquids). 281 pp. MGU, Moscow, 1963 6. GOST 8.207-76. Pryamye izmereniya s mnogokratnymi nablyudeniyami. Metody obrabotki rezul'tatov nablyudenii (Direct Measurements with Repeated Observations. Methods of Treating the Results of the Observations). 10 pp. Standartov, Moscow, 1978 7. P. DEBYE and A. M. BUECHE, J. Chem. Phys. 18: 1423, 1950 8. A. A. TAGER, V. M. ANDREYEVA and Ye. M. YEVSINA, Vysokomol. soyed. 6: 1901, 1964 (Translated in Polymer Sci. U.S.S.R. 6: 10, 2107, 1964) 9. A. A. TAGER and V. M. ANDREYEVA, J. Polymer Sci. C16: 1145, 1967 10. G.P. ROSHCHINA, Kriticheskiye yavleniya i flyuktuatsii v raslvorakh (Critical Phenomena and Fluctuations in Solutions), p. 109, Akad. l'4auk SSSR, Moscow, 1960 11. M. I. SHAKHPARONOV and N. G. SHLENKINA, Zh. fiz. khim. 28: 1910, 1954 12. I. PRIGOGINE and R. DUFAY, Khimicheskaya termodinamika (Chemical Thermodynamics) (Translated from the English, Ed. V. A. Mikhailov). 510 pp, Nauka, Novosibirsk, 1966
2762
S. A. VSHIVKOVand I. I. ISAKOVA
13. L N. BRONSHTEIN and K. A. SEMENDYAYEV, Spravochnik po matematike (Reference Book on Mathematics). 10th Stereotype Edition, p. 391, Fizmatgiz, Moscow, 1962 14. A. A. TAGER, Fizikokhimiya polimerov (Polymer Physical Chemistry). 3rd Revised Edition. 544 pp. Khimiya, Moscow, 1978 15. I.S. BEREZIN and N. P. ZHIDKOV, Metody vychislenii (Methods of Calculations) 3rd Edition, Revised and Supplemented. 1: 55, Nauka, Moscow, 1966
Polymer Science U.S.S.R. Vol. 28, No. 12, pp. 2762-2768, 1986 Printed in Poland
0032-3950/86 $10.00 +.00 © 1987 Pergamon Journals Ltd.
PHASE EQUILIBRIUM AND THE STRUCTURE OF THE SYSTEMS POLYMETHYLMETHACRYLATE-PHOSPHATE PLASTICIZERS * S. A. VSHIVKOVand I. I. ISAKOVA Gorkii Urals State University
(Received 29 April 1985) Refractometry, light scatter and the turbidity spectrum methods have been used to study the phase equilibrium and structure of polymethylmethacrylate--alkyl halogen phosphate plasticized systems. Fall in Tj on plasticization is compared with change in such structural parameters of the systems as concentration fluctuations and the size of the supramolecular particles. Tim MECHANICALproperties of plasticized systems widely used in industry are largely determined by the compatibility of the components, i.e. their mutual solubilities. In this connexion it is necessary to determine the diagrams of state o f plasticized systems and the parameters o f the thermodynamic affinity of the polymer for plasticizer. The value of the thermodynamic affinity determines the form o f the concentration~dependence of the glass transition point TS which is usually related to the corresponding change in the structure o f the polymer [1]. However, investigations comparing fall in Tg with change in the structural parameters of the systems on plasticization are virtually absent. In the present work we study the structure o f the PMMA-alkylhalogen phosphate systems by light scatter and turbidity spectrum over the whole range of compositions and determine their diagrams of state and Tg. * Vysokomol. soyed. A28: No. 12, 2488-2492, 1986.
0032-39J01S6 $10.00+.00 ~ 1987Pergamon Journals Ltd.
THERMODYNAMIC AFFINITY OF OLIGOMERIC DIMETHYLSILOXANE F O R T O L U E N E AS~ R E V E A L E D BY RAYLEIGH LIGHT SCATTER AND STATIC SORPTION* N. V. KORIDZE,A. A. TAGER,V. M. ANDREYEVA, L. V. ADAMOVAand S. A. NEFEDOV Gorkii Urals State University
(Received 24 April 1985) Raleigh light scatter has been used to study the general scatter and degree of depolarization of scattered light of solution of oligo-dimethylsiloxane in toluene over the whole concentration range. Static isothermal sorption of toluene vapours on the oligomer at 298 K was investigated. The concentration functions of the differences in the chemical potentials of the components zl/h and the Gibbs mixing energy A# "~ of the oligomer with toluene have been calculated in the whole range of compositions.
of Rayleigh light scatter developed by Einstein and Smolukhovskii for two-component systems establishes the link between the intensity of the scattered light on the fluctuations in concentration and the thermodynamic stability of the system expressed by a second derivative of the mean Gibbs mixing energy by composition ~92(AOm)/Ox~.For solutions of low molecular weight liquids good agreement of the values of the excess Gibbs energy gE, calculated from the data on light scatter on the fluctuations in concentration and from the vapour pressure over the solution has been demonstrated [1, 2]. For polymer solutions the possibility of calculating the thermodynamic parameters of affinity from the light scatter data has been demonstrated in two studies [3, 4]; the values of the differences in the chemical potential of the solvent A/z, and the Flory-Huggins parameter Z calculated in the region of moderately concentrated solutions satisfactorily agreed with the data of the method of equilibrium ultracentriguation [3]. The aim of the present work is to determine the Gibbs mixing energy of a polymer with solvent over the whole region of compositions by the Rayleigh light scatter method and compare the results with the method of static isothermal sorption usually employed for this purpose. T H E THEORY
Oligo-dimethylsiloxane of PMS-100 grade with 37L~=4000 was investigated. The light scatter o f the PMS solutions in toluene over the whole range of compositions was measured with the FPS-3 M nephelometer; the standard was calibrated against benzene (Rb= 16.3 x 10 -4 m -x, 2 = 546 nm) [5]. We determined the relative coefficient of total scatter Rt and the degree of depolarization o f t h e scat-
* Vysokomol. soyed. A28: No. 12, 2483-2487, 1986. 2757
N.V. KORIDZEet aL
2758
tered light Au at an angle of 90° for non-polarized incident light (2 = 546 nm) at 298 K. The refractive indices n of the solutions were measured with the IRF-23 refractometer for green light from the spectrum of a mercury lamp. For the experiments on light scatter oligomeric PMS was cleared of dust by centrifugation for 3 hr at 1.7 x 104 rpm; the quality of purification was checked against absence of asymmetry of the light scatter indicatrix. The solutions were prepared directly in the cuvette for measuring the light scatter by diluting purified PMS with dust-free toluene. The composition was expressed in gravimetric fractions of the oligomer co2. Isothermal sorption of toluene on PMS at 298 K was studied by a gravimetric method in the region of relative vapour pressure of the solvent PIPsfrom 0.07 to 0.92 using quartz spiral balances with a sensitivity 3'6 x 102 m/kg. The toluene vapour pressure was measured with the OM-2 optical manometer with graduation 0"02 Pa. The calculations of the parameters of thermodynamic affinity from the data on light scatter and static sorption were based on a programme written in FORTRAN IV language using a computer. In measuring light scatter the maximum total error [6] in the determination of Ro and A. did not exceed 3"6 and 9'4 Yorespectively and in calculating the magnitude tgz(,J#'~)/&o2 11 Yo.In the sorption experiments the error in measuring PIPs did not exceed 2"5 ~o and in calculating the magnitude Air1 4 %. Figure 1 gives for the PMS solutions in toluene the concentration functions of total scatter Rt, the degree of depolarization of the scattered light Au and the scatter on the concentration fluctuations Rc calculated from the equation [5]
Rc=Rt( 1 13 Au " ~ - R ( 6 I+--AJ
,
1
13 _~__~ ) ( 1 _ o 9 2 ) _ R 2 ( 1 6 1 ~,
13 -A~2 ,/ c o 2 , 6 l+Au2 ]
(1)
where R1 and -Rz are the coefficients o f total scatter o f light o f the components; Au~, Au2 are the degrees of depolarization of the scattered light o f toluene and PMS respectively. It shows that the curves Rt =f(c02) and Rc =f(co2) are extremal and the maxima are shifted to the region of dilute solutions ( c o ~ = 0.13). Similar dependences of excess light scatter have been obtained for PS solutions is a number of solvents [7-9]. Extremal changes in Rt with composition are also observed for mixtures of low molecular weight liquids the components of which greatly differ in the size of the molecules [10]. In the PMS-toluene systems studied the main contribution to total scatter is made by R, which indicates heavy fluctuations in concentration in the region of the extreme. The degree of depolarization of the scattered light of the solution diminishes in the region of compositions from pure toluene to co~a~ and then remains practically constant. Similar changes in Au for the mixtures benzene-methanol and chlorobenzenemethanol were found in reference [11]. T h e pattern observed in both cases is connected with the large difference in A~ of the mixed components. In the region of concentrated solutions the introduction of toluene into PMS does not significantly alter the optical anisotropy of the system and A~ remains constant to co~a~; in the region of dilute solutions the main contribution is made by anisotropic toluene which also leads to sharp rise in Au with dolution. F r o m Fig. 1 we calculated the second derivatives of the G i b b s mixing energy by composition from the equation [1 ]
a2(Ao m) 7t~RT { -
c3n ~2/,
2n . . . .
9n 2
\2
1 V--,
Thermodynamic affinity of oligomeric dimethylsiloxane~for toluene
2759
where R is the universal gas constant; T is temperature, K; 2 is the wavelength o f the incident light; -NA is the Avogadro mtmber; o is the specific volume of the solution calculated by the additive scheme. Figure 2 presents the concentration function 0 2 (Ag=)/ao922. It will be seen that the values of the derivative are positive in the whole range of compositions, the branches of the curve move to + oo and the position of the minimum along the axis of compositions corresponds to the m a x i m u m of the curve Re. The error in determination o f 02(z~gm)/&o 2 in the region of concentrated solutions rises which is due to the small values of Rc tending to zero at coz~l. Similar curves were obtained from the data on light scatter by moderately concentrated polymer solutions in references [3, 4]. Using the relation [12] a2(Ag m) 1 O(d/~) .
.
0o92
.
.
.
(3)
.
co2 &o2
/I
t80-
•
=
,/!,
120
i Rt , l O~,tn -~ 5
Au
66
3 ;
,_0.2
I 0"1";
Fie. 1
0-8 COz
I
1
0.4
I
i
o.~
t.t);,:.
FIG. 2
FIG. 1. Concentration dependence of total light scatter Rt(1), degree of depolarization ,4.(2) and scatter on concentration fluctuations Re(3) calculated from eqn. (1) of PMS solutions in toluene at 298 K. FIG. 2. Concentration dependence c32(dg")/&o~ of PMS solutions in toluene at 298 K determined, by light scatter method; maximum error of measurements shown by dot-dash line.
N . V . KORIDZEet al.
2760
f r o m the area under the curve o92aZ(Agm)/Oo92=f(og2) f r o m the Simpson f o r m u l a [13] we calculated the A/z1 values; the difference in the chemical potential o f the oligomer zl/t2 was determined f r o m the G i b b s - D u h e m equation [14] nt,~
Alt2=-f~2d(A#~),
(4)
--00
and f r o m the relation
(5)
Ag" = o91Alq + 0)2 Alz2 we calculated the Gibbs mixing energy o f polymer with solvent.
0.4
0.8 ~ z
-5
45
~/m 0"4
0"2 -8#
0.4
0.8
P/Ps F1o. 3
4g%d~,,%,kJ/kg FIG. 4
FIo. 3. Sorption isotherm of toluene vapours on PMS at 298 K. x is the equilibrium amount of sorbate vapours absorbed by weight sample of oligomer m. Fzo. 4. Concentration dependence Agm(1, 1'), A/z1 (2, 2') and A/z2(3, 3') of PMS solutions in toluene at 298 K calculated from light scatter (1-3) and sorption (1"-3') data.
Thermodynamic affinity of oligomeric dimethylsiloxane for toluene
2761
The data on the static sorption o f toluene vapours on PMS are given in Fig. 3. The sorption isotherm has the form of a curve concave to the ordinate axis o v e r the whole range of pips characteristic of elastomers [14]. F r o m these data we calculated the magnitudes A/z1 for the region of compositions from 0.98 to 0.70 of the weight fraction o f PMS f r o m the equation [14] A/~1 = R T In P/Ps
(6)
For the region of lower concentrations the A/t1 values were calculated by interpolation by the Eitken scheme [15] with a computer from a p r o g r a m m e drawn up by us. Figure 4 presents the concentration functions Apt, A/z2 and Ag m of P M S solutions in toluene calculated from eqn. (4)-(6) on the basis o f the light scatter and sorption data. In both cases the function Ag m is expressed by a curve with a minimum lying in the negative region; the values of A/A and Ap2 decrease from 0 to - o o and the curves intersect at the point of the minimum of the curve Ag m, which is in accord with the laws of thermodynamics [12]. These results show that from the experimental data on the isothermal sorption o f the vapour o f a low molecular weight liquid on a polymer in a comparatively narrow concentration region one may calculate the parameters of thermodynamic affinity over the whole concentration range. The curves A#~, Ap2 and zlgm=f(o~2) obtained from the data of the sorption method agree within the limits o f the errors of the experiment and calculation with the data of the light scatter method. These results indicate the desirability o f using the data on light scatter by polymer solutions to calculate the parameters of the thermodynamic affinity of the components.
Translated by A. CROZY
REFERENCES 1. M. F. VUKS, Rasseyaniye sveta v gazakh, zhidkostyakh i rastworakh (Light Scatter in Gases, Liquids and Solutions), 320 pp., Leningr. State Univ., Leningrad, 1977 2. D.J. COUMOU and E. L. MARKOR, Trans. Faraday Soc. 60: 1726, 1964 3. L G. SCHOLTE, Europ. Polymer J. 6: 1063, 1970 4. V. M. ANDREYEVA, A. A. TAGER, I. S. FOMINJYKH and O. L. ZAMARAYEVA, Vysokotool. soyed. A18: 286, 1976 (Translated in Polymer Sci. U.S.S.R. A18: 2, 328, 1976) 5. M. I. SHAKHPARONOV, Metody issledovaniya teplovogo dvizheniya molekul i stroyeniya zhidkostei (Methods of Investigating the Thermal Motion of Molecules and the Structure of Liquids). 281 pp. MGU, Moscow, 1963 6. GOST 8.207-76. Pryamye izmereniya s mnogokratnymi nablyudeniyami. Metody obrabotki rezul'tatov nablyudenii (Direct Measurements with Repeated Observations. Methods of Treating the Results of the Observations). 10 pp. Standartov, Moscow, 1978 7. P. DEBYE and A. M. BUECHE, J. Chem. Phys. 18: 1423, 1950 8. A. A. TAGER, V. M. ANDREYEVA and Ye. M. YEVSINA, Vysokomol. soyed. 6: 1901, 1964 (Translated in Polymer Sci. U.S.S.R. 6: 10, 2107, 1964) 9. A. A. TAGER and V. M. ANDREYEVA, J. Polymer Sci. C16: 1145, 1967 10. G.P. ROSHCHINA, Kriticheskiye yavleniya i flyuktuatsii v raslvorakh (Critical Phenomena and Fluctuations in Solutions), p. 109, Akad. l'4auk SSSR, Moscow, 1960 11. M. I. SHAKHPARONOV and N. G. SHLENKINA, Zh. fiz. khim. 28: 1910, 1954 12. I. PRIGOGINE and R. DUFAY, Khimicheskaya termodinamika (Chemical Thermodynamics) (Translated from the English, Ed. V. A. Mikhailov). 510 pp, Nauka, Novosibirsk, 1966
2762
S. A. VSHIVKOVand I. I. ISAKOVA
13. L N. BRONSHTEIN and K. A. SEMENDYAYEV, Spravochnik po matematike (Reference Book on Mathematics). 10th Stereotype Edition, p. 391, Fizmatgiz, Moscow, 1962 14. A. A. TAGER, Fizikokhimiya polimerov (Polymer Physical Chemistry). 3rd Revised Edition. 544 pp. Khimiya, Moscow, 1978 15. I.S. BEREZIN and N. P. ZHIDKOV, Metody vychislenii (Methods of Calculations) 3rd Edition, Revised and Supplemented. 1: 55, Nauka, Moscow, 1966
Polymer Science U.S.S.R. Vol. 28, No. 12, pp. 2762-2768, 1986 Printed in Poland
0032-3950/86 $10.00 +.00 © 1987 Pergamon Journals Ltd.
PHASE EQUILIBRIUM AND THE STRUCTURE OF THE SYSTEMS POLYMETHYLMETHACRYLATE-PHOSPHATE PLASTICIZERS * S. A. VSHIVKOVand I. I. ISAKOVA Gorkii Urals State University
(Received 29 April 1985) Refractometry, light scatter and the turbidity spectrum methods have been used to study the phase equilibrium and structure of polymethylmethacrylate--alkyl halogen phosphate plasticized systems. Fall in Tj on plasticization is compared with change in such structural parameters of the systems as concentration fluctuations and the size of the supramolecular particles. Tim MECHANICALproperties of plasticized systems widely used in industry are largely determined by the compatibility of the components, i.e. their mutual solubilities. In this connexion it is necessary to determine the diagrams of state o f plasticized systems and the parameters o f the thermodynamic affinity of the polymer for plasticizer. The value of the thermodynamic affinity determines the form o f the concentration~dependence of the glass transition point TS which is usually related to the corresponding change in the structure o f the polymer [1]. However, investigations comparing fall in Tg with change in the structural parameters of the systems on plasticization are virtually absent. In the present work we study the structure o f the PMMA-alkylhalogen phosphate systems by light scatter and turbidity spectrum over the whole range of compositions and determine their diagrams of state and Tg. * Vysokomol. soyed. A28: No. 12, 2488-2492, 1986.