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Study of the kinetics of polycondensation of the salts of dicarboxylic acids and diamines in solution
Polycondensation of salts of dicarboxylic acids and diamines in solution
823
5. Ye. I. KROPACHEVA, V. A. DOLGOPLOSK, Yu. S. PATRUSHIN and D. Ye. STERENZAT, Ibid. 195: 1628, 1970 6. L. M. ZEMTSOV, G. P. KARPACHEVA, B. E. DAVYDOV and N. F. ZALIZNAYA, Tez. dokl. IV Mezhdunar. simpoz, po gomogennomu katalizu (Summaries of Reports to Fourth International Symposium on Homogeneous Catalysis). Vol. 3, p. 130, Leningrad, 1984 7. T. MASUDA, T. TAKAHASHI, K. JAMAMOTO and T. HIGASHIMURA, J. Polymer Sci. Polymer Chem. Ed. 20: 2603, 1982 8. T. J. KATZ and S. J. LEE, J. Amer. Chem. Soc. 102: 422, 1980 9. Ye. I. KROPACHEVA, B. A. DOLGOPLOSK, D. Ye. STERENZAT and Yu. A. PATRUSHIN, Dokl. Akad. Nauk SSSR 195: 1388, 1970 10. M. A. GEIDERIKH, B. E. DAVYDOV, N. F. ZALIZNAYA and V. S. MINAYEVA, Vysokomol. soyed. A18: 1264, 1976 (Translated in Polymer Sci. U.S.S.R. 18: 6, 1451, 1976) 11. Yu. K. YUR'EV, Prakticheskiye raboty po organicheskoi khimii (Practical Work on Organic Chemistry). pp. 47, 51, 70, Moscow, t961 12. B. A. DOLGOPLOSK and Ye. I. TINYAKOVA, Metalloorganicheskii kataliz v protsessakh polimerizatsii (Organometal Catalysis in Polymerization Processes). p. 9, Moscow, 1982 13. S. A. SMIRNOV, I. A. KOP'EVA, I. A. ORESHKIN, Ye. I. TINYAKOVA and B. A. DOLGOPLOSK, Dokl. Akad. Nauk SSSR 239: 392, 1978
Polymer ScienceU.S.S.R.Vol. 29, No. 4, pp. 823-828, 1987 Printed in Poland
0032-3950/87 $10.00+.00 © 1988Pergamon Preas pie
STUDY OF THE KINETICS OF POLYCONDENSATION OF THE SALTS OF DICARBOXYLIC ACIDS AND DIAMINES IN SOLUTION * A. P. KHARDIN
(dec.),
I. A. NOVAKOV, S. S. RADCHENKO, [. A. KULEV, B. S. ORLINSON,
F. B. SHERMAN, I. A. VOSKRESENSKAYAan d K. A.. BIRZNIYEKS Volgograd Polytechnical Institute
(Receh~ed 22 Auqust 1985) The kinetics of the reaction of high temperature polycondensation of the salts of bifunctional alicyclic derivatives in solution has been investigated for the first time by the method of reaction microaquametry. The kinetic and thermodynamic characteristics of the process have been determined. It is established that the reactivity of the salts of the adamantane derivatives are at the level or somewhat below that of the salt of adipic acid and hexamethylene diamine. A. CONSIDERABLE n u m b e r o f publications is c o n c e r n e d with study o f the r e a c t i o n o f p o l y c o n d e n s a t i o n o f the salts o f dicarboxylic acids a n d diamines in the solid p h ase * Vysokomol. soyed. A29: No. 4, 743-746, 1987.
824
A.P. KHARDINet al.
[1, 2] and in solution [3]. The reactivity of the alicyclic dicarboxylic acids and diamines has been far less studied. In the present work the method of reaction microaquametry is used to study the kinetics of the polycondensation reaction of adamantane-containing salts of the following dicarboxylic acids and diamines: 1,3-bis-(carboxy)adamantane and 1,6-hexamethylenc diamine (I), 1,3-bis-(carboxymethyl)adamantane and 1,6-hexamethylene diamine (II), 1-carboxy-3-carboxymethyladamantane and 1,6-hexamethylene diamine (III), adipic acid and 1,3-bis-(aminomethyl)adamantane (IV), adipic acid and 1,3-bis-(aminoethyl)adamantane (V), terephthalic acid and 1,3-bis-(aminomethyl)adamantane (VI), isophthalic acid and 1,3-bis-(aminomethyl)adamantane (VII) using for comparison the salts of the following compounds adipic acid and 1,6-hexamethylene diamine (VIII), 1,4-cis, trans-bis-(carboxy)cyclohexane and 1,6-hexamethylene diamine (IX), adipic acid and 1,3-cis, trans-bis-(aminomethyl)cyclohexane (X), 2,2-bis-(carboxy)-l,1dicyclohexane and 1,6-hexamethylene diamine (XI), isophthalic acid and 1,3-bis-(aminomethyl)benzene (XII), isophthalic acid and 1,6-hexamethylene diamine (XHI) and terephthalic acid and 1,6-hexamethylene diamine (XIV). The kinetics of the formation of the polyamides was investigated by the method of direct titration of the water evolved by the K. Fischer reagent (titre 0.7-0.95 mg/ml) in line with the technique in [4, 5]. The concentration of the initial reagent 0.03 mole/l, consumption of inert gas 0.5 ml/sec. As solvent'we used a mixture of octylphenols with the boiling point 280-285°C in which many aliphatic and aromatic polyamides are well soluble. Synthesis and purification of the adamantane-eontainlng diamines and diacids were carried out in accord with the techniques in [5-7]. The samples of the test compounds were first dried in vaeuo at 50-60°C. Their Fischer moisture content was less than 0-1%. Control experiments showed that the solvent used practically does not interact with the carboxyl groups of the carboxylic acids. It was also established that the rate of removal of water from the solvent indicated at 230-260°C and consupmtion of inert gas 0.5 ml/sec is one to two orders higher than that of the reaction water during polycondensation. The error of the experimental data does not exceed 10 7oo. The polycondensation reaction of the above compounds may be represented in the form A+B~C+D where A is a diamine, B a dicarboxylic acid, C a polyamide and D water. Table 1 indicates the degrees of conversion of the salts of the dicarboxylic acids and diamines. As may be seen from the data presented conversion at 260°C in 132 × 102 see is in the interval 73.5-98~. Considering that the process occurs at 230-260°C, the reaction water formed is constantly carried off from the reaction zone by the current of inert gas and the degree of conversion at a definite time interval for all the starting compounds investigated by us approaches lOOK, the rate constants were calculated in line with the equation for irreversible reactions [8]. In plotting the graph of the function log x - r the experimental points did not fit a straight line and, consequently the reaction of polyamide formation from the salts
Poiycondensstion of dicarboxylic
of salts of dicarboxylic acids and diamines in solution
acids and diamines
does not obey the kinetic
patterns
825
for first order
irreversible reactions. The effective reaction rate constants were defined as the tangent of the angle of slope of the straight lines plotted in the coordinates l/x-z. (z is the duration of the process which corresponds to second order irreversible bimolecular reactions), The samilogarithmic anamorphoses of the kinetic curves of polycondensation of the salts are presented in Fig. 1. The values of the rate constants k found for the process indicated are presented in Table 1. From analysis of the data it follows that the dicarboxylic acids of the adamantane series are less reactive than adipic acid and in order of fall in
k they may be arranged
in the series
HOOC(CH2),COOH>HOOCH,C-R-CH,COOH CH,COOH
11=
where
D
7
and consequently
the adamantane nucleus the In the series of alicyclic (carboxy)-l,l-dicyclohexane reactivity is characteristic
TABLE
1.
RATE
CONSTANTS
OF
* At 260°C
ConversPns of salts*, % 73.5 97.0 84.5 97.5 97.2 80.0 95.0
and for B duration
with distancing
of the carboxyl
group
reactivity of the salts in this series rises. dicarboxylic acids (1,3-bis-(carboxy)-adamantane, and 1,4-c& trans-bis-(carboxy) cyclohexane) of the second compound (k =0.64 x lo-*
THE
POLYCONDENSATION ACIDS
-Starting compounds for the synthesis of the polyamides -__ I 11 111 IV V VI VII
>HOOC-R-
>HOOC-R-COOH,
’
AND
OF
THE
SALTS
OF
2,2-bisthe least l./mole*sec).
D~CARROXYIJC
DIAMINES
Starting corn- ! jounds for the Conversions ynthesis of the of salts*, % polyamides 1
kx102, l./mole.sec 0.69
1.64 0.92 3.92 3.22 0.82 2.37
REACTION
from
VIII IX X XI
Ii
i/ _I.~.
XII XIII XIV
98.0 88.5 97.6 76.4 94.9 86.0 81.0
’
I /
k x 1 Oz,
’
I./mole.sec
I- ~~ ~___~ ___~_ 3.10 1.18 6.44 0.64 1.67 1.22 0.91
of synthesis 132 x lo2 set
As Table I indicates the introduction of the phenylene radicals between the reaction centres lowers the reactivity of the dicarboxylic acids, thus, for example, k for compound l XIV is 0.91 x lo-* l./mole*sec and in the same conditions for compound IX k= 1.18 x x lo-* l./mole*sec. Comparison of the reactivity in the series of diamines chosen (1,6_hexamethylenc diamine, 1,3-bis-(aminomethyl) adamantane, I ,3-bis-(aminoethyl) adamatane and I ,3cis, rruns-bis-(aminomethyl) cyclohexane) shows that these diamines insignificantly differ in reactivity.
A . P . KrIARDINet "aL
826
To calculate the thermodynamic characteristics of the process we determined k of the polycondensation of some salts at different temperatures. As shown by the investigations and calculations made the temperature dependence of k obeys the Arrhenius equation (Fig. 2). The kinetic and thermodynamic characteristics of the process of formation of the polyamides for the salts studied are presented in Table 2. F r o m the data presented it will be seen that the effective activation energy of the salts used is 44.60-65.46 kJ/mole, the smaller value of the activation energy being characteritsic of the compounds V I I I and IV and the larger of the compound II. A similar relation was also detected by us in change in the activation enthalpy of the process. According to the published findings [9] bimolecular reactions proceed at normal rates if k = 10 tl × exp ( - E / R T ) . For the compounds studied 1~' us the pre-exponential multiplier is 10 s.2s - 1012.7~ and consequently at 230-260 ° C polycondensation proceeds at quite high rates.
1/~" I/mole .vm u ~
60
50
~
nz w ° z
o o o
o
1 X N V,~I . ~ I
xN
.:~
60
o o o
50
qO
40
20
qO
20
140 "~ , 10 -z, sec
F1o. 1. Semilogarithmicanamorphosesofthekineticcurvesofpolycondensationofthesalts of dicarboxylic acids and diamines. Temperature of reaction 260°C. Here and in Fig. 2, the curve numbers correspond to number for the starting compound in the Tables.
['9
Z.O
1o3/r, K-'
F1o. 2. Arrhenius dependence of the reaction rate constants of the formation of polyamides.
Polycondensation of salts of dicarboxylic acids and diamines in solution TABLE 2.
KINETIC
82?
AND THERMODYNAMIC CHARACTERISTICS OF THE POLYCONDENSATION REACTION OF THE SALTS OF DICARBOXYLIC ACIDS AND DIAMINE,$
compounds for the synthesis of polyamides VII1
11
IV
2 •
T
o
kxl0
,
AH ~
..........
l./mole'sec 260 250 240 230 260 250 240 230 260 250 240 230 260 250 240 230
A S #,
J]deg" mole
kJ/mole
log A
3"10 2"45 1 "95 1 "55 0"69 0'54 0"43 0"33
44'60
40.17
-
208"4
8'28
54'17
49.74
-
202.9
9"86
1"64
65'46
61 '03
-
169.2
12.78
44.60
40.17
- 209.1
1"12
0"87 0"65 3"92 3"16 2"48 1 "95
8'25
Analysis o f Table 2 also shows that the activation e n t r o p y has a negative value a n d in the series o f c o m p o u n d s m e n t i o n e d a m o u n t s to - ( 1 6 9 . 2 - 2 0 9 . 1 ) J/deg.mole. Thus, the patterns of p o l y c o n d e n s a t i o n of the salts of dicarboxylic acids a n d diamines have been investigated a n d the kinetic a n d t h e r m o d y n a m i c characteristics o f the process determined. To o b t a i n high molecular weight polyamides based o n salts c o n t aining a d a m a n t a n e fragments it is necessary to increase slightly the d u r a t i o n o f the process as c o m p a r e d with p o l y c o n d e n s a t i o n of the commercial m o n o m e r VIII. Translated by
A. CROZY
REFERENCES I. A. V. VOLOKHINA.and G. I. KUDRYAVTSEV, Khim. volokna, 5, 13, 1959 2. G.I. KUDRYAVTSEV, M. P. NOSOV and A. V. VOLOKHINA, Poliamidnye volokna (Polyamide Fibres). p. 43, Moscow, 1976 3. V. V. KORSHAK and T. M. FRUNZE, Sinteticheskiye geterotsepnye poliamidy (Synthetic Heterochain Polyamides).'p. 120, Moscow, 1962 4. S. V. VINOGRADOVA, Z. V. GERASHCHENKO, Ya. S. VYGODSKII, F. B. SHERMAN and V. V. KORSHAK, Dokl. Akad. Nauk SSSR 203: 821, 1972 5. S. S. NOVIKOV, A. P. KHARDIN, Ya. S. VYGODSKII, F. B. SHERMAN, I. A. NOVAKOV, B. S. ORLINSON and S. S. RADCHENKO, Vysokomol. soyed. B22: 678, 1989 (Not translated in Polymer Sci. U.S.S.R.) 6. I. A. NOVAKOV, Dissert. Cand. Chem. Sci. 154 pp. Volgograd, 1975
828
T . E . LIPATOVAet aL
7. L. N. BUTENKO, V. Ye. DERBISHER, A. P. KHARDIN and A. I. SHREIBERT, Zh. organ. khim. 9: 728, 1973 8. N. M. EMANUEL' and D. G. KNORRE, Kurs khimicheskoi kinetiki (Course on Chemical Kinetics) 3rd Edition, revised and supplemented. 400 pp. Moscow, 1974 9. E. A. MELVIN-HUGHES, Ravnovesiye i kinetika reaktsii v rastvorakh (Equilibrium and Kinetics of Reactions in Solutions). p. 94, Moscow, 1975
Polymer Science U.S.S.R. Vol. 29, No. 4, pp. 828-834, 1987 Printed in Poland
0032-3950/87 $10.00+.00 © 1988 Pergamon Press pie
ASPECTS OF THE EFFECT OF AEROSIL ON THE STRUCTURE AND PROPERTIES OF FILLED NETWORK POLYURETHANES* T. E. LIPATOVA, L. S. SHEININA, L. YU. VLADIMIROVA and Yu. V. MASLAK Institute of Chemistry of High Molecular Weight Compounds, Ukr.S.S.R. Academy of Sciences (Received 26 August 1985)
The structure and properties of network PUs based on polyoxypropylene glycol, trimethylolpropane and toluylene-2,4- or diphenylmethane-4,4'-diisocyanate cured in presence of different amounts of Aerosil have been studied. The possibility of evaluating the contribution of the two types of specific bonds to the network structure of filled PUs is demonstrated. Aerosil has a fundamentally different influence on the formation of the network structure of polymers obtained from diisocyanates of symmetrical and non-symmetrical structure, reflected in the values of the effective density of the PU cross link. OBTAINING network PUs in presence o f highly disperse mineral fillers involves different changes in the structul e o f the matrix polymer [l]. In particular, in the region o f small fillings polymers often f o r m with a more defective (as c o m p a r e d with unfilled PUs) structure o f the n e t w o r k [1-3]. Study of the role of highly disperse solid additives in the reactions o f formation o f network PUs showed that the a m o u n t o f filler, in particular, Aerosil, determines the degree o f completion o f the reaction in which the process o f structural gel formation begins in the system [4]. The character o f the effect o f Aerosill differs for the reaction mixtures cured on the basis o f the diisocyanates o f symmetrical and non-symmetrical structure [4]. The start o f structural gel formation is characterized by passage o f the reaction P U mixtures f r o m the h o m o g e n e o u s to the microheterogeneous state the qualitative evaluation o f which is presented in [5]. The role o f the filler in the process o f structuring m a y be a consequence o f its different influence on the h o m o geneity o f the cured reaction mixture. This is all the more probable since the P U s based * Vysokomol. soyed. A29: No. 4, 747-752, 1987.
823
5. Ye. I. KROPACHEVA, V. A. DOLGOPLOSK, Yu. S. PATRUSHIN and D. Ye. STERENZAT, Ibid. 195: 1628, 1970 6. L. M. ZEMTSOV, G. P. KARPACHEVA, B. E. DAVYDOV and N. F. ZALIZNAYA, Tez. dokl. IV Mezhdunar. simpoz, po gomogennomu katalizu (Summaries of Reports to Fourth International Symposium on Homogeneous Catalysis). Vol. 3, p. 130, Leningrad, 1984 7. T. MASUDA, T. TAKAHASHI, K. JAMAMOTO and T. HIGASHIMURA, J. Polymer Sci. Polymer Chem. Ed. 20: 2603, 1982 8. T. J. KATZ and S. J. LEE, J. Amer. Chem. Soc. 102: 422, 1980 9. Ye. I. KROPACHEVA, B. A. DOLGOPLOSK, D. Ye. STERENZAT and Yu. A. PATRUSHIN, Dokl. Akad. Nauk SSSR 195: 1388, 1970 10. M. A. GEIDERIKH, B. E. DAVYDOV, N. F. ZALIZNAYA and V. S. MINAYEVA, Vysokomol. soyed. A18: 1264, 1976 (Translated in Polymer Sci. U.S.S.R. 18: 6, 1451, 1976) 11. Yu. K. YUR'EV, Prakticheskiye raboty po organicheskoi khimii (Practical Work on Organic Chemistry). pp. 47, 51, 70, Moscow, t961 12. B. A. DOLGOPLOSK and Ye. I. TINYAKOVA, Metalloorganicheskii kataliz v protsessakh polimerizatsii (Organometal Catalysis in Polymerization Processes). p. 9, Moscow, 1982 13. S. A. SMIRNOV, I. A. KOP'EVA, I. A. ORESHKIN, Ye. I. TINYAKOVA and B. A. DOLGOPLOSK, Dokl. Akad. Nauk SSSR 239: 392, 1978
Polymer ScienceU.S.S.R.Vol. 29, No. 4, pp. 823-828, 1987 Printed in Poland
0032-3950/87 $10.00+.00 © 1988Pergamon Preas pie
STUDY OF THE KINETICS OF POLYCONDENSATION OF THE SALTS OF DICARBOXYLIC ACIDS AND DIAMINES IN SOLUTION * A. P. KHARDIN
(dec.),
I. A. NOVAKOV, S. S. RADCHENKO, [. A. KULEV, B. S. ORLINSON,
F. B. SHERMAN, I. A. VOSKRESENSKAYAan d K. A.. BIRZNIYEKS Volgograd Polytechnical Institute
(Receh~ed 22 Auqust 1985) The kinetics of the reaction of high temperature polycondensation of the salts of bifunctional alicyclic derivatives in solution has been investigated for the first time by the method of reaction microaquametry. The kinetic and thermodynamic characteristics of the process have been determined. It is established that the reactivity of the salts of the adamantane derivatives are at the level or somewhat below that of the salt of adipic acid and hexamethylene diamine. A. CONSIDERABLE n u m b e r o f publications is c o n c e r n e d with study o f the r e a c t i o n o f p o l y c o n d e n s a t i o n o f the salts o f dicarboxylic acids a n d diamines in the solid p h ase * Vysokomol. soyed. A29: No. 4, 743-746, 1987.
824
A.P. KHARDINet al.
[1, 2] and in solution [3]. The reactivity of the alicyclic dicarboxylic acids and diamines has been far less studied. In the present work the method of reaction microaquametry is used to study the kinetics of the polycondensation reaction of adamantane-containing salts of the following dicarboxylic acids and diamines: 1,3-bis-(carboxy)adamantane and 1,6-hexamethylenc diamine (I), 1,3-bis-(carboxymethyl)adamantane and 1,6-hexamethylene diamine (II), 1-carboxy-3-carboxymethyladamantane and 1,6-hexamethylene diamine (III), adipic acid and 1,3-bis-(aminomethyl)adamantane (IV), adipic acid and 1,3-bis-(aminoethyl)adamantane (V), terephthalic acid and 1,3-bis-(aminomethyl)adamantane (VI), isophthalic acid and 1,3-bis-(aminomethyl)adamantane (VII) using for comparison the salts of the following compounds adipic acid and 1,6-hexamethylene diamine (VIII), 1,4-cis, trans-bis-(carboxy)cyclohexane and 1,6-hexamethylene diamine (IX), adipic acid and 1,3-cis, trans-bis-(aminomethyl)cyclohexane (X), 2,2-bis-(carboxy)-l,1dicyclohexane and 1,6-hexamethylene diamine (XI), isophthalic acid and 1,3-bis-(aminomethyl)benzene (XII), isophthalic acid and 1,6-hexamethylene diamine (XHI) and terephthalic acid and 1,6-hexamethylene diamine (XIV). The kinetics of the formation of the polyamides was investigated by the method of direct titration of the water evolved by the K. Fischer reagent (titre 0.7-0.95 mg/ml) in line with the technique in [4, 5]. The concentration of the initial reagent 0.03 mole/l, consumption of inert gas 0.5 ml/sec. As solvent'we used a mixture of octylphenols with the boiling point 280-285°C in which many aliphatic and aromatic polyamides are well soluble. Synthesis and purification of the adamantane-eontainlng diamines and diacids were carried out in accord with the techniques in [5-7]. The samples of the test compounds were first dried in vaeuo at 50-60°C. Their Fischer moisture content was less than 0-1%. Control experiments showed that the solvent used practically does not interact with the carboxyl groups of the carboxylic acids. It was also established that the rate of removal of water from the solvent indicated at 230-260°C and consupmtion of inert gas 0.5 ml/sec is one to two orders higher than that of the reaction water during polycondensation. The error of the experimental data does not exceed 10 7oo. The polycondensation reaction of the above compounds may be represented in the form A+B~C+D where A is a diamine, B a dicarboxylic acid, C a polyamide and D water. Table 1 indicates the degrees of conversion of the salts of the dicarboxylic acids and diamines. As may be seen from the data presented conversion at 260°C in 132 × 102 see is in the interval 73.5-98~. Considering that the process occurs at 230-260°C, the reaction water formed is constantly carried off from the reaction zone by the current of inert gas and the degree of conversion at a definite time interval for all the starting compounds investigated by us approaches lOOK, the rate constants were calculated in line with the equation for irreversible reactions [8]. In plotting the graph of the function log x - r the experimental points did not fit a straight line and, consequently the reaction of polyamide formation from the salts
Poiycondensstion of dicarboxylic
of salts of dicarboxylic acids and diamines in solution
acids and diamines
does not obey the kinetic
patterns
825
for first order
irreversible reactions. The effective reaction rate constants were defined as the tangent of the angle of slope of the straight lines plotted in the coordinates l/x-z. (z is the duration of the process which corresponds to second order irreversible bimolecular reactions), The samilogarithmic anamorphoses of the kinetic curves of polycondensation of the salts are presented in Fig. 1. The values of the rate constants k found for the process indicated are presented in Table 1. From analysis of the data it follows that the dicarboxylic acids of the adamantane series are less reactive than adipic acid and in order of fall in
k they may be arranged
in the series
HOOC(CH2),COOH>HOOCH,C-R-CH,COOH CH,COOH
11=
where
D
7
and consequently
the adamantane nucleus the In the series of alicyclic (carboxy)-l,l-dicyclohexane reactivity is characteristic
TABLE
1.
RATE
CONSTANTS
OF
* At 260°C
ConversPns of salts*, % 73.5 97.0 84.5 97.5 97.2 80.0 95.0
and for B duration
with distancing
of the carboxyl
group
reactivity of the salts in this series rises. dicarboxylic acids (1,3-bis-(carboxy)-adamantane, and 1,4-c& trans-bis-(carboxy) cyclohexane) of the second compound (k =0.64 x lo-*
THE
POLYCONDENSATION ACIDS
-Starting compounds for the synthesis of the polyamides -__ I 11 111 IV V VI VII
>HOOC-R-
>HOOC-R-COOH,
’
AND
OF
THE
SALTS
OF
2,2-bisthe least l./mole*sec).
D~CARROXYIJC
DIAMINES
Starting corn- ! jounds for the Conversions ynthesis of the of salts*, % polyamides 1
kx102, l./mole.sec 0.69
1.64 0.92 3.92 3.22 0.82 2.37
REACTION
from
VIII IX X XI
Ii
i/ _I.~.
XII XIII XIV
98.0 88.5 97.6 76.4 94.9 86.0 81.0
’
I /
k x 1 Oz,
’
I./mole.sec
I- ~~ ~___~ ___~_ 3.10 1.18 6.44 0.64 1.67 1.22 0.91
of synthesis 132 x lo2 set
As Table I indicates the introduction of the phenylene radicals between the reaction centres lowers the reactivity of the dicarboxylic acids, thus, for example, k for compound l XIV is 0.91 x lo-* l./mole*sec and in the same conditions for compound IX k= 1.18 x x lo-* l./mole*sec. Comparison of the reactivity in the series of diamines chosen (1,6_hexamethylenc diamine, 1,3-bis-(aminomethyl) adamantane, I ,3-bis-(aminoethyl) adamatane and I ,3cis, rruns-bis-(aminomethyl) cyclohexane) shows that these diamines insignificantly differ in reactivity.
A . P . KrIARDINet "aL
826
To calculate the thermodynamic characteristics of the process we determined k of the polycondensation of some salts at different temperatures. As shown by the investigations and calculations made the temperature dependence of k obeys the Arrhenius equation (Fig. 2). The kinetic and thermodynamic characteristics of the process of formation of the polyamides for the salts studied are presented in Table 2. F r o m the data presented it will be seen that the effective activation energy of the salts used is 44.60-65.46 kJ/mole, the smaller value of the activation energy being characteritsic of the compounds V I I I and IV and the larger of the compound II. A similar relation was also detected by us in change in the activation enthalpy of the process. According to the published findings [9] bimolecular reactions proceed at normal rates if k = 10 tl × exp ( - E / R T ) . For the compounds studied 1~' us the pre-exponential multiplier is 10 s.2s - 1012.7~ and consequently at 230-260 ° C polycondensation proceeds at quite high rates.
1/~" I/mole .vm u ~
60
50
~
nz w ° z
o o o
o
1 X N V,~I . ~ I
xN
.:~
60
o o o
50
qO
40
20
qO
20
140 "~ , 10 -z, sec
F1o. 1. Semilogarithmicanamorphosesofthekineticcurvesofpolycondensationofthesalts of dicarboxylic acids and diamines. Temperature of reaction 260°C. Here and in Fig. 2, the curve numbers correspond to number for the starting compound in the Tables.
['9
Z.O
1o3/r, K-'
F1o. 2. Arrhenius dependence of the reaction rate constants of the formation of polyamides.
Polycondensation of salts of dicarboxylic acids and diamines in solution TABLE 2.
KINETIC
82?
AND THERMODYNAMIC CHARACTERISTICS OF THE POLYCONDENSATION REACTION OF THE SALTS OF DICARBOXYLIC ACIDS AND DIAMINE,$
compounds for the synthesis of polyamides VII1
11
IV
2 •
T
o
kxl0
,
AH ~
..........
l./mole'sec 260 250 240 230 260 250 240 230 260 250 240 230 260 250 240 230
A S #,
J]deg" mole
kJ/mole
log A
3"10 2"45 1 "95 1 "55 0"69 0'54 0"43 0"33
44'60
40.17
-
208"4
8'28
54'17
49.74
-
202.9
9"86
1"64
65'46
61 '03
-
169.2
12.78
44.60
40.17
- 209.1
1"12
0"87 0"65 3"92 3"16 2"48 1 "95
8'25
Analysis o f Table 2 also shows that the activation e n t r o p y has a negative value a n d in the series o f c o m p o u n d s m e n t i o n e d a m o u n t s to - ( 1 6 9 . 2 - 2 0 9 . 1 ) J/deg.mole. Thus, the patterns of p o l y c o n d e n s a t i o n of the salts of dicarboxylic acids a n d diamines have been investigated a n d the kinetic a n d t h e r m o d y n a m i c characteristics o f the process determined. To o b t a i n high molecular weight polyamides based o n salts c o n t aining a d a m a n t a n e fragments it is necessary to increase slightly the d u r a t i o n o f the process as c o m p a r e d with p o l y c o n d e n s a t i o n of the commercial m o n o m e r VIII. Translated by
A. CROZY
REFERENCES I. A. V. VOLOKHINA.and G. I. KUDRYAVTSEV, Khim. volokna, 5, 13, 1959 2. G.I. KUDRYAVTSEV, M. P. NOSOV and A. V. VOLOKHINA, Poliamidnye volokna (Polyamide Fibres). p. 43, Moscow, 1976 3. V. V. KORSHAK and T. M. FRUNZE, Sinteticheskiye geterotsepnye poliamidy (Synthetic Heterochain Polyamides).'p. 120, Moscow, 1962 4. S. V. VINOGRADOVA, Z. V. GERASHCHENKO, Ya. S. VYGODSKII, F. B. SHERMAN and V. V. KORSHAK, Dokl. Akad. Nauk SSSR 203: 821, 1972 5. S. S. NOVIKOV, A. P. KHARDIN, Ya. S. VYGODSKII, F. B. SHERMAN, I. A. NOVAKOV, B. S. ORLINSON and S. S. RADCHENKO, Vysokomol. soyed. B22: 678, 1989 (Not translated in Polymer Sci. U.S.S.R.) 6. I. A. NOVAKOV, Dissert. Cand. Chem. Sci. 154 pp. Volgograd, 1975
828
T . E . LIPATOVAet aL
7. L. N. BUTENKO, V. Ye. DERBISHER, A. P. KHARDIN and A. I. SHREIBERT, Zh. organ. khim. 9: 728, 1973 8. N. M. EMANUEL' and D. G. KNORRE, Kurs khimicheskoi kinetiki (Course on Chemical Kinetics) 3rd Edition, revised and supplemented. 400 pp. Moscow, 1974 9. E. A. MELVIN-HUGHES, Ravnovesiye i kinetika reaktsii v rastvorakh (Equilibrium and Kinetics of Reactions in Solutions). p. 94, Moscow, 1975
Polymer Science U.S.S.R. Vol. 29, No. 4, pp. 828-834, 1987 Printed in Poland
0032-3950/87 $10.00+.00 © 1988 Pergamon Press pie
ASPECTS OF THE EFFECT OF AEROSIL ON THE STRUCTURE AND PROPERTIES OF FILLED NETWORK POLYURETHANES* T. E. LIPATOVA, L. S. SHEININA, L. YU. VLADIMIROVA and Yu. V. MASLAK Institute of Chemistry of High Molecular Weight Compounds, Ukr.S.S.R. Academy of Sciences (Received 26 August 1985)
The structure and properties of network PUs based on polyoxypropylene glycol, trimethylolpropane and toluylene-2,4- or diphenylmethane-4,4'-diisocyanate cured in presence of different amounts of Aerosil have been studied. The possibility of evaluating the contribution of the two types of specific bonds to the network structure of filled PUs is demonstrated. Aerosil has a fundamentally different influence on the formation of the network structure of polymers obtained from diisocyanates of symmetrical and non-symmetrical structure, reflected in the values of the effective density of the PU cross link. OBTAINING network PUs in presence o f highly disperse mineral fillers involves different changes in the structul e o f the matrix polymer [l]. In particular, in the region o f small fillings polymers often f o r m with a more defective (as c o m p a r e d with unfilled PUs) structure o f the n e t w o r k [1-3]. Study of the role of highly disperse solid additives in the reactions o f formation o f network PUs showed that the a m o u n t o f filler, in particular, Aerosil, determines the degree o f completion o f the reaction in which the process o f structural gel formation begins in the system [4]. The character o f the effect o f Aerosill differs for the reaction mixtures cured on the basis o f the diisocyanates o f symmetrical and non-symmetrical structure [4]. The start o f structural gel formation is characterized by passage o f the reaction P U mixtures f r o m the h o m o g e n e o u s to the microheterogeneous state the qualitative evaluation o f which is presented in [5]. The role o f the filler in the process o f structuring m a y be a consequence o f its different influence on the h o m o geneity o f the cured reaction mixture. This is all the more probable since the P U s based * Vysokomol. soyed. A29: No. 4, 747-752, 1987.