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Studies in the field of cyclic polymerization and copolymerization—XXIII. Study of the radical polymerization of dimethylvinylethinylcarbinol
Cyclic polymerization and c o p o l y m e r i z a t i o n - - X X I I I
1043
CONCLUSIONS
The polyeondensation of aluminium butylate and ethylate with dlbutyl, dlethyl and diphenyl esters of methylphosphinic acid was investigated. It is shown that, in this reaction, simple esters separate and polymers form with an inorganic chain containing sequentially linked atoms of alnminium, oxygen and phosphorus. Translated by E. SEMERE REFERENCES 1. K. A. ANDRIANOV, A. A. ZHDANOV and A. A. KAZAKOVA, Izv. Akad. Nauk. SSSR, Otd Khim. n. 466, 1959 2. K. A. ANDRIANOV, A. A. ZHDANOV and A. A. KAZAKOVA, Zh, obshch, kbiimi 29: 1281, 1959 3. K. A. ANDRIANOV and V. M. NOVIKOV, Vysokomol. soyed. 1 : 1930, 1959 4. K. A. ANDRIANOV, L. M. KHANANASHVILI, A. A. ZHDANOV and A. G. SHAPATIN, Zh. Obshch. khimii 31: 224, 1961 5. K. A. ANDRIANOV, L. M. KHANANASHVILI, A. A. KAZAKOVA and A. N. IVANOV, Zh. obshch, khimii 31: 228. 1961 6. K. A. ANDRIANOV and A. A. KAZAKOVA, Plast. massy, No. 3, 24, 1963 7. Sintezy organieheskikh preparatov. (Synthesis of Organic CompoundsJ Sb. 2, Izd. in. ]it. 1949
STUDIES IN THE FIELD OF CYCLIC POLYMERIZATION AND COPOLYMERIZATION--XXIH. STUDY OF THE RADICAL POLYMERIZATION OF DIMETHYLVINYLETHINYLCARBINOL* S. G. MATSOYA:N a n d N. M. MORLYAN Institute of Organic Chemistry, Armenian S.S.R. Academy of Sciences
(Received 2 July 1963)
UNTIL now, there has been hardly any information available in the literature on the properties and structure of polymers of 1,3-enine systems. It is well known that the study of polymerization of vinylacetylene hydrocarbons [1] in vinylacetylene alcohols [2] was held back by the impossibility of obtaining soluble final polymers. Partial polymerization products of dimethylvinylethinylcarbinol (DMVEC) have satisfactory adhesion and have, therefore, found wide applications in engineering for joining various materials [3]. According to Nazarov and Terekhov * Vysokomol. soyed. 6: :No. 5, 945-950, 1964.
1044
S.G. MATS0YANand N. M. MORLYAN
[2], the initial polymerization of DMVEC is of the same type as polymerization of vinylacetylene [4] with multi-stage polymerization of double and treble bonds 6-9 of monomer units and formation of cyclobutene rings: CH2=CH__I--(CHa)'COH, (x ÷I)CH~=CHC-C--C(CH3)~
-
--
~ I --C
=
C
I_
CH~--CH--
_
x --C-CC (CH3)~
I OH where x : 5-8. Further, three-dimensional polymerization of these intermediate low-molecular weight polymers, with diminution of vinyl and ethinyl groups, causes the formation of a cross-linked polymer in the form of an insoluble vitreous mass [2]. We previously established that the cause of formation of insoluble, vitreous final polymers of vinylethinylcarbinols and their esters is insufficient elimination of unreacted monomer from polymerization products; with careful purification (by re-precipitation), the polymers separate as soluble powders which are not cross-linked and are fully stable in air even when heated [5, 6]. The molecular weight of these polymers, according to the nature of vinylacetylene carbinol and the method of polymerization, varies within a wide range (104-3.5× 106). The degree of residual unsaturation of the polymers obtained, irrespective of the degree of polymerization, is ~ 50% per unit of monomer in all cases, the unsaturation being taken as 100°/o . It has been shown b y chemical methods (ozonization, bromination, hydration, acetylation, alkali decomposition) and spectroscopic investigation that the polymer unit is formed b y cyclization of two monomer molecules and contains a non-conjugated double bond (in a five-membered ring), and a treble, bond. From the data obtained, we propose a chain mechanism of polymerization of vinylethinylcarbinols with participation of the free radical [7, 8] according to the scheme: OH OH OH Ix. . I I CH~= CHC ~ C--C<-+RCH~CH= C= C--C<->RCHaCH= C = C--C < / > C - - C - C--CH--CH s [ I OH RCHsCI-I= Ctt --__CHsCH__CH__ - - --RCH~CH--CH I ~H I ] I CH C--C< J~ //C--C< CH e--c< I\// I +-c eH I I\// I <----C CH O H III OH C CH OH Ill
fll
_
C I
>C--0H
_ In
c I >C--OH
C
I >C--OH
Chain growth takes place as a result of sequential linkage of the growing radical to two monomer molecules in the 1,4 and 1,2 position (because of the
Cyclic polymerization and c o p o l y m e r i z a t i o n - - X X I I I
1045
instability of the allene radical) with formation of an unsaturated dimer radical which becomes stabilized as a result of allene-diene isomerization and intramolecular cyclization. This complex mechanism of chain growth, as compared with polymerization of ordinary monomers, made it necessary to investigate the process of DMVEC polymerization and the properties of polymers thus formed.
RESULTS AND DISCUSSION
The monomer (DMVEC) was purified by washing the industrial product with a 10% solution of sodium hydroxide, then with water until neutral and by double distillation (after drying over MgSOd) at reduced pressure: b.p. 52°/10 ram; 2O 1"4750; d~° 0.8916. ~D
Methanol, used as solvent, was purified by conventional methods. Benzoyl peroxide (BP) and azo-isobutyro-dinitrile (AID) purified by recrystallization, were used as initiators. Polymerization was carried out in bulk and in methanol solutions in glass ampoules or dilatometric ampoules at 50-80°C. In the kinetic experiments, monomer was used immediately after distillation. The degree of polymerization was determined dilatometrically or by re-precipitation of the polymer from a methanol solution with water and drying residue to constant weight i n v a c u o (10 mni) at 54 °. The results obtained by both methods agree satisfactorily. In all cases DMVEC polymers were obtained in the form of white powders soluble in lower alcohols, acetone and dioxane, but insoluble in water, benzene and petroleum ether. To study the properties of the polymers formed, the mean molecular weights of poly-DMVEC fractions were determined osmotically and viscometric tests made on the specimens (see Table). DEPENDENCE
O F I N T R I N S I C V I S C O S I T k ~ ([q]) O N
MOLECULARWEIGHT(M)
[~]
M, found by an osmometric method
M, calculated by formula (1)
0.417 0.500 0.680 0.780 0.870 1.200 1.455 2.100
110,300 138,700 229,500 298,000 320,000 538,500 721,200 1,205,000
107,700 141,800 226,000 278,200 328,200 534,300 715,500 1,247,000
1046
S.G. MATSOYANand N. M. MORLYAN
It was found that the Huggins constant for the poly-DMVEC-alcohol system is 0.33. From tabulated data the dependence of log [~] on log M was evaluated which, within the range of experimental error, appeared to be strictly linear. The relation thus derived between intrinsic viscosity (in absolute alcohol at 20°C) and molecular weight 6an be expressed b y the equation It/]= 1.99× 10 -4 × M °'66.
(1)
As can be seen from the Table, the molecular weight values measured and calculated from formula (1) agree satisfactorily. Investigations have shown that the molecular weight of poly-DMVEC depends to a considerable extent on the method and conditions of polymerization. B y studying the integral and differential curves of molecular-weight distribution, it was established that polymers of DMVEC are comparatively uniformly dispersed. The multiple dispersion factor calculated as the ratio of weight-average and average molecular weights, varies from 1.05 to 1.08. The glass temperature of DMVEC polymers, according to molecular weight, is within the range of 80-90°C. When heating fused DMVEC polymers to 150-170°C cross-linking takes place along existing unsaturated bonds with formation of a solid insoluble polymer. In this respect the powdered poly-DMVEC resembles thermo-setting resins and can be used for several technical purposes. The kinetics of polymerization of DMVEC, initiated b y B P at various temperatures and concentrations of the monomer and initiator, are shown in Fig. 1.
a
b
I, ,o
~ 20
I
t
120
I
I
240
I
I
360
I
I
480
I
Time, rain
I
120
I
I
240
I
I
I
360
Fro. 1. Kinetics of polymerization of DMVEC: a--in bulk. BP concentration 0.5 moles-% (of monomer); temperature: /--60 °, 2--70 °, 3--75 °, 4--80°; b--in methanol solution. BP concentration 2 moles-% (of monomer); monomer concentration at polymerization temperature: 1--50%, 60°; 2--50%, 70°; 3--50%, 80% 4--70%, 80°. During bulk polymerization of DMVEC, as can be seen from Fig. la, the process takes place at a constant rate with a degree of conversion of ~ 50%.
1047
Cyclic polymerization and copolymerization--XXIII
T h e kinetic curves are s m o o t h to a m a x i m u m degree of conversion (80-85%) b o t h for b u l k a n d solution p o l y m e r i z a t i o n and, consequently, acceleration of p o l y m e r i z a t i o n (gel effect), in p r o p o r t i o n to p o l y m e r formation, is n o t observed. I n d e e d , the p o l y m e r i z a t i o n r a t e for b o t h b u l k a n d solution, u p to high degrees of conversion, is satisfactorily r e p r e s e n t e d b y an e q u a t i o n of the first order. The linear d e p e n d e n c e of p o l y m e r i z a t i o n rate on initial D M V E C c o n c e n t r a t i o n shown in Fig. 2a, confirms the first order relationship in respect of m o n o m e r . v, 104 mole/L sec v,
tO4,mole/l.sec Q
4"0
3"0 2 20
1.0
2
4
6
[M], rnole/L
i
I
I
I
0"1
0:2
0"3
0"4
FIG. 2. Dependence of the rate of DMVEC polymerization (v): a--on the concentration of DMVEC in methanol: 1 --at 60°, BP concentration 0.0602 mole/1.; 2--at 80 °, BP concentration 0.0172 mole/1.; b--on initiator concentration ([I]). In bulk: 1--BP, 50°, 2--AID, 60°; 3--BP, 60°; X--in a solution of methanol, monomer concentration 3.81 mole/1, initiator--BP, 80°. To elucidate the effect of the n a t u r e a n d c o n c e n t r a t i o n of the initiator on t h e p o l y m e r i z a t i o n rate, a series of e x p e r i m e n t s was carried out a t 50-80°C in t h e presence of B P a n d AID. I t follows from Fig. 2b, t h a t irrespective of reaction conditions, the p o l y m e r i z a t i o n rate is proportional to the square root of the c o n c e n t r a t i o n of the initiator; at the same time the n a t u r e of radical initiation (peroxide or azo-initiation) has no practical effect on p o l y m e r i z a t i o n rate. Thus, the overall D M V E C p o l y m e r i z a t i o n r a t e (v) is in direct p r o p o r t i o n to the first p o w e r o f m o n o m e r c o n c e n t r a t i o n ([M)] a n d to the square root of the initiato'r c o n c e n t r a t i o n ([I]). This kinetic b e h a v i o u r is fully consistent with the c o n v e n t i o n a l e q u a t i o n of chain p o l y m e r i z a t i o n rate in liquid phase [9]: v =kg ~ ~, [M] x/[I],
[2]
where k~, k i, k b are the respective r a t e constants of growth, initiation and breakage.
1048
S. G. MATSOYANand 1~. M. MORLYAN
The strict observance of the proportionality of v and the square root [I] confirm bimolecular breakage of reacting chains. As evidence of the breakage reaction b y interaction of polymer radicals, m a y be cited the fact that the mean coefficient of DMVEC polymerization, as can be seen from Fig. 3, is inversely proportional to the square root of initiator concentration.
n,tO -2 16
12
8
1 4
8
12
:FIG. 3. Dependence of t,he coefficient of polymerization (n) of poly-DMVEC on BP concentration: 1 - i n methanol, monomer concentration 3.81 mole/1, 80°C; 2--in bulk, 60°C; 3--in bulk, 50°C.
The absence of gel effect during polymerization is, apparently, explained b y the nature of DMVEC, the hydroxyl groups of which are capable of forming hydrogen bonds. A slight variation of the mean molecular weight of poly-DMVEC, according to the degree of conversion, (Fig. 4) also confirms the absence of the gel effect. The total activation energy of DMVEC polymerization in bulk calculated from the effective polymerization rate constant (Fig. 5a) at different temperatures, is 21.6 kcal/mole. The value found agrees in practice with the activation energy (20.9 kcal/mole) of polymerization of DMVEC in methanol solution (Fig. 5b). The effective activation energy of polymerizatio n , according to equation (2) is E=I/2Ei+(E~--I/2Eb), where E i, Eg, E b are the activation energies of elementary reactions of initiation (for B P E i - 30 kcal/mole), growth and breakage of chains respectively. The value of (Eg--1/2Eb)for DMVEC is 6.6 kcal/mole, which satisfactorily agrees with the value of 4-7 kcal/mole for m a n y monomers in radical polymerization [9]. Thus, all the data in the investigation of polymerization of DMVEC are quite consistent with the mechanism of polymerization of conventional monomers. From these data it can be assumed that the initial step, the addition of the growing radical to the first monomer molecule, is the limiting stage in the complex
Cyclic polymerization and copolymerization--XXIII
1049
m e c h a n i s m of D M V E C chain growth. The remaining stages of chain g r o w t h {dimerization, isomerization and eyclization) r e p r e s e n t reactions t a k i n g place r a p i d l y with a low e n e r g y threshold, caused b y the stabilization of the initial allene radical. 5+logk
M,1o"|
18
15( ~ 10 5
14 1
b
12
[ I ., 40 80 Depth o f convepsion , %
280
I 2-90
300 1/T , 103
FIG. 4 FId. 5 Fi6'. 4. Dependence of the molecular weight (M) of poly-DMVEC on the degree of conversion: 1 - a t 80°C; 2--at 70°C. FI(~. 5. Dependence of the logarithm of effective polymerization rate constant (log k) of DMVEC on --in bulk; b --in methanol solution.
l/T: a
CONCLUSIONS
(1) Radical p o l y m e r i z a t i o n of d i m e t h y l v i n y l e t h i n y l c a r b i n o l in bulk and in m e t h a n o l solution has been i n v e s t i g a t e d in the range of 50-80°; the effect o f initial m o n o m e r a n d initiator c o n c e n t r a t i o n on the rate of p o l y m e r i z a t i o n has been studied. (2) I t has been f o u n d t h a t , u n d e r the conditions studied, high-molecular weight linear-cyclic p o l y m e r s form, for which the relation between intrinsic viscosity a n d molecular weight takes the form: [~]= 1.99 × 10 -~ x M ° % (3) I t was established t h a t the overall r a t e of p o l y m e r i z a t i o n is in d i r e c t p r o p o r t i o n to the first power o f m o n o m e r c o n c e n t r a t i o n and to the square r o o t of initiator c o n c e n t r a t i o n ; u p to the m a x i m u m degree of m o n o m e r conversion (80-85%) a u t o - a c c e l e r a t i o n of p o l y m e r i z a t i o n (gel effect) was n o t observed. I t has been shown t h a t the m e a n coefficient of p o l y m e r i z a t i o n is in inverse p r o p o r t i o n to the square r o o t of initiator concentration. (4) I t was f o u n d t h a t , for d i m e t h y l v i n y l e t h i n y l c a r b i n o l , value is 6.6 kcal/mole which is in satisfactory a g r e e m e n t with the m e c h a n i s m of chain p o l y m e r i z a t i o n of conventional monomers. E. SEMERE
(E.~--I/2E~)
Translatedby
REFERENCES
1. 2. 3. 4.
C. PRICE and F. MCKEON, J. Polymer Sci. 41: 445, 1959 I. N. NAZAROV and L. N. TEREKHOVA, Izv. Akad. Nauk SSSR, Otd. khim. n. 66, 1950 I. P. BERDINSKIKI'I, Klei i skleivaniye. (Glues and Glueing.) Mashgiz, 1952 H. DYKSTRA, J. Amer. Chem. Soc. 56: 1625, 1934
1050
YE. V. SHARKOVA et al.
5. 'S. G. MATSOYAN, N. M. MORLYAN and E. Ts. GEVORKYAN, Auth. Cert. U.S.S.R. 155605, 1961 6. S. G. MATSOYAN, N. M. MORLYAN and E. Ts. GEVORKYAN, Auth. Cert. U.S.S.R. 155606, 1961 7. S. G. MATSOYAN, N. M. MORLYAN and A. A. SAAKYAN, Izv. Akad. Nauk ArmSSR, Khim. 11. 15: 405, 1962 8. S. G. MATSOYAN and N. M. MORLYAN, Izv. Akad. Nauk. ArmSSR, Khim. n. 16: 347, 1963 9. Kh. S. BAGDASARYAN, Teoriya radikal'noi polimcrizatsii. (Theory of Radical Polymerization.) Moscow, 1959
STUDY OF CONVERSIONS, ANALOGOUS TO POLYMERIZATION OF CELLULOSE AND POLYGLYCIDYL METHACRYLATE GRAFT COPOLYMER*t YE. F. SHARKOVA, A. D. VIRNIK and Z. A. ROGOVIN t Moscow Textile Institute
(Received 2 J u l y 1963)
ONE of the chief methods of modifying the properties of cellulose materials is synthesis of cellulose graft copolymers. Considerable interest is attracted to the synthesis of cellulose graft copolymers containing reactive groups in the macromolecule; by using these groups it is possible to modify further the cellulose graft copolymers. This paper is devoted to the investigation of conversions of cellulose and polyglycidyl methacrylate ~ graft copolymer which are analogous to polymerization. The presence of epoxy groups in the cellulose and polyglycidylmethacrylate graft copolymer makes it possible to effect several conversions analogous to polymerization. We studied some of the possible analogous conversions of cellulose and polyglycidyl methacrylate graft copolymer. We investigated the reaction of cellulose and polyglycidyl methacrylate graft copolymer with sodium bisulphite, sodium sulphite, ammonia, monoethanolamine and diethylamine. * Vysokomol. soycd. 6: No. 5, 951-956, 1964. ~f 150th paper from the series "Study of the structure and properties of cellulose and its derivatives". Experimental part of the study carried out with the participation of K. K. Shevarov. § After this paper had been completed, a report was published on the work of Kurosaki and Ivakura, who synthesized cellulose and polyglycidyl methaerylate graft copolymer and, as a result of the interaction of epoxy groups of this copolymer with the aminogroups of the dye, obtained a synthetic coloured fibre [1].
1043
CONCLUSIONS
The polyeondensation of aluminium butylate and ethylate with dlbutyl, dlethyl and diphenyl esters of methylphosphinic acid was investigated. It is shown that, in this reaction, simple esters separate and polymers form with an inorganic chain containing sequentially linked atoms of alnminium, oxygen and phosphorus. Translated by E. SEMERE REFERENCES 1. K. A. ANDRIANOV, A. A. ZHDANOV and A. A. KAZAKOVA, Izv. Akad. Nauk. SSSR, Otd Khim. n. 466, 1959 2. K. A. ANDRIANOV, A. A. ZHDANOV and A. A. KAZAKOVA, Zh, obshch, kbiimi 29: 1281, 1959 3. K. A. ANDRIANOV and V. M. NOVIKOV, Vysokomol. soyed. 1 : 1930, 1959 4. K. A. ANDRIANOV, L. M. KHANANASHVILI, A. A. ZHDANOV and A. G. SHAPATIN, Zh. Obshch. khimii 31: 224, 1961 5. K. A. ANDRIANOV, L. M. KHANANASHVILI, A. A. KAZAKOVA and A. N. IVANOV, Zh. obshch, khimii 31: 228. 1961 6. K. A. ANDRIANOV and A. A. KAZAKOVA, Plast. massy, No. 3, 24, 1963 7. Sintezy organieheskikh preparatov. (Synthesis of Organic CompoundsJ Sb. 2, Izd. in. ]it. 1949
STUDIES IN THE FIELD OF CYCLIC POLYMERIZATION AND COPOLYMERIZATION--XXIH. STUDY OF THE RADICAL POLYMERIZATION OF DIMETHYLVINYLETHINYLCARBINOL* S. G. MATSOYA:N a n d N. M. MORLYAN Institute of Organic Chemistry, Armenian S.S.R. Academy of Sciences
(Received 2 July 1963)
UNTIL now, there has been hardly any information available in the literature on the properties and structure of polymers of 1,3-enine systems. It is well known that the study of polymerization of vinylacetylene hydrocarbons [1] in vinylacetylene alcohols [2] was held back by the impossibility of obtaining soluble final polymers. Partial polymerization products of dimethylvinylethinylcarbinol (DMVEC) have satisfactory adhesion and have, therefore, found wide applications in engineering for joining various materials [3]. According to Nazarov and Terekhov * Vysokomol. soyed. 6: :No. 5, 945-950, 1964.
1044
S.G. MATS0YANand N. M. MORLYAN
[2], the initial polymerization of DMVEC is of the same type as polymerization of vinylacetylene [4] with multi-stage polymerization of double and treble bonds 6-9 of monomer units and formation of cyclobutene rings: CH2=CH__I--(CHa)'COH, (x ÷I)CH~=CHC-C--C(CH3)~
-
--
~ I --C
=
C
I_
CH~--CH--
_
x --C-CC (CH3)~
I OH where x : 5-8. Further, three-dimensional polymerization of these intermediate low-molecular weight polymers, with diminution of vinyl and ethinyl groups, causes the formation of a cross-linked polymer in the form of an insoluble vitreous mass [2]. We previously established that the cause of formation of insoluble, vitreous final polymers of vinylethinylcarbinols and their esters is insufficient elimination of unreacted monomer from polymerization products; with careful purification (by re-precipitation), the polymers separate as soluble powders which are not cross-linked and are fully stable in air even when heated [5, 6]. The molecular weight of these polymers, according to the nature of vinylacetylene carbinol and the method of polymerization, varies within a wide range (104-3.5× 106). The degree of residual unsaturation of the polymers obtained, irrespective of the degree of polymerization, is ~ 50% per unit of monomer in all cases, the unsaturation being taken as 100°/o . It has been shown b y chemical methods (ozonization, bromination, hydration, acetylation, alkali decomposition) and spectroscopic investigation that the polymer unit is formed b y cyclization of two monomer molecules and contains a non-conjugated double bond (in a five-membered ring), and a treble, bond. From the data obtained, we propose a chain mechanism of polymerization of vinylethinylcarbinols with participation of the free radical [7, 8] according to the scheme: OH OH OH Ix. . I I CH~= CHC ~ C--C<-+RCH~CH= C= C--C<->RCHaCH= C = C--C < / > C - - C - C--CH--CH s [ I OH RCHsCI-I= Ctt --__CHsCH__CH__ - - --RCH~CH--CH I ~H I ] I CH C--C< J~ //C--C< CH e--c< I\// I +-c eH I I\// I <----C CH O H III OH C CH OH Ill
fll
_
C I
>C--0H
_ In
c I >C--OH
C
I >C--OH
Chain growth takes place as a result of sequential linkage of the growing radical to two monomer molecules in the 1,4 and 1,2 position (because of the
Cyclic polymerization and c o p o l y m e r i z a t i o n - - X X I I I
1045
instability of the allene radical) with formation of an unsaturated dimer radical which becomes stabilized as a result of allene-diene isomerization and intramolecular cyclization. This complex mechanism of chain growth, as compared with polymerization of ordinary monomers, made it necessary to investigate the process of DMVEC polymerization and the properties of polymers thus formed.
RESULTS AND DISCUSSION
The monomer (DMVEC) was purified by washing the industrial product with a 10% solution of sodium hydroxide, then with water until neutral and by double distillation (after drying over MgSOd) at reduced pressure: b.p. 52°/10 ram; 2O 1"4750; d~° 0.8916. ~D
Methanol, used as solvent, was purified by conventional methods. Benzoyl peroxide (BP) and azo-isobutyro-dinitrile (AID) purified by recrystallization, were used as initiators. Polymerization was carried out in bulk and in methanol solutions in glass ampoules or dilatometric ampoules at 50-80°C. In the kinetic experiments, monomer was used immediately after distillation. The degree of polymerization was determined dilatometrically or by re-precipitation of the polymer from a methanol solution with water and drying residue to constant weight i n v a c u o (10 mni) at 54 °. The results obtained by both methods agree satisfactorily. In all cases DMVEC polymers were obtained in the form of white powders soluble in lower alcohols, acetone and dioxane, but insoluble in water, benzene and petroleum ether. To study the properties of the polymers formed, the mean molecular weights of poly-DMVEC fractions were determined osmotically and viscometric tests made on the specimens (see Table). DEPENDENCE
O F I N T R I N S I C V I S C O S I T k ~ ([q]) O N
MOLECULARWEIGHT(M)
[~]
M, found by an osmometric method
M, calculated by formula (1)
0.417 0.500 0.680 0.780 0.870 1.200 1.455 2.100
110,300 138,700 229,500 298,000 320,000 538,500 721,200 1,205,000
107,700 141,800 226,000 278,200 328,200 534,300 715,500 1,247,000
1046
S.G. MATSOYANand N. M. MORLYAN
It was found that the Huggins constant for the poly-DMVEC-alcohol system is 0.33. From tabulated data the dependence of log [~] on log M was evaluated which, within the range of experimental error, appeared to be strictly linear. The relation thus derived between intrinsic viscosity (in absolute alcohol at 20°C) and molecular weight 6an be expressed b y the equation It/]= 1.99× 10 -4 × M °'66.
(1)
As can be seen from the Table, the molecular weight values measured and calculated from formula (1) agree satisfactorily. Investigations have shown that the molecular weight of poly-DMVEC depends to a considerable extent on the method and conditions of polymerization. B y studying the integral and differential curves of molecular-weight distribution, it was established that polymers of DMVEC are comparatively uniformly dispersed. The multiple dispersion factor calculated as the ratio of weight-average and average molecular weights, varies from 1.05 to 1.08. The glass temperature of DMVEC polymers, according to molecular weight, is within the range of 80-90°C. When heating fused DMVEC polymers to 150-170°C cross-linking takes place along existing unsaturated bonds with formation of a solid insoluble polymer. In this respect the powdered poly-DMVEC resembles thermo-setting resins and can be used for several technical purposes. The kinetics of polymerization of DMVEC, initiated b y B P at various temperatures and concentrations of the monomer and initiator, are shown in Fig. 1.
a
b
I, ,o
~ 20
I
t
120
I
I
240
I
I
360
I
I
480
I
Time, rain
I
120
I
I
240
I
I
I
360
Fro. 1. Kinetics of polymerization of DMVEC: a--in bulk. BP concentration 0.5 moles-% (of monomer); temperature: /--60 °, 2--70 °, 3--75 °, 4--80°; b--in methanol solution. BP concentration 2 moles-% (of monomer); monomer concentration at polymerization temperature: 1--50%, 60°; 2--50%, 70°; 3--50%, 80% 4--70%, 80°. During bulk polymerization of DMVEC, as can be seen from Fig. la, the process takes place at a constant rate with a degree of conversion of ~ 50%.
1047
Cyclic polymerization and copolymerization--XXIII
T h e kinetic curves are s m o o t h to a m a x i m u m degree of conversion (80-85%) b o t h for b u l k a n d solution p o l y m e r i z a t i o n and, consequently, acceleration of p o l y m e r i z a t i o n (gel effect), in p r o p o r t i o n to p o l y m e r formation, is n o t observed. I n d e e d , the p o l y m e r i z a t i o n r a t e for b o t h b u l k a n d solution, u p to high degrees of conversion, is satisfactorily r e p r e s e n t e d b y an e q u a t i o n of the first order. The linear d e p e n d e n c e of p o l y m e r i z a t i o n rate on initial D M V E C c o n c e n t r a t i o n shown in Fig. 2a, confirms the first order relationship in respect of m o n o m e r . v, 104 mole/L sec v,
tO4,mole/l.sec Q
4"0
3"0 2 20
1.0
2
4
6
[M], rnole/L
i
I
I
I
0"1
0:2
0"3
0"4
FIG. 2. Dependence of the rate of DMVEC polymerization (v): a--on the concentration of DMVEC in methanol: 1 --at 60°, BP concentration 0.0602 mole/1.; 2--at 80 °, BP concentration 0.0172 mole/1.; b--on initiator concentration ([I]). In bulk: 1--BP, 50°, 2--AID, 60°; 3--BP, 60°; X--in a solution of methanol, monomer concentration 3.81 mole/1, initiator--BP, 80°. To elucidate the effect of the n a t u r e a n d c o n c e n t r a t i o n of the initiator on t h e p o l y m e r i z a t i o n rate, a series of e x p e r i m e n t s was carried out a t 50-80°C in t h e presence of B P a n d AID. I t follows from Fig. 2b, t h a t irrespective of reaction conditions, the p o l y m e r i z a t i o n rate is proportional to the square root of the c o n c e n t r a t i o n of the initiator; at the same time the n a t u r e of radical initiation (peroxide or azo-initiation) has no practical effect on p o l y m e r i z a t i o n rate. Thus, the overall D M V E C p o l y m e r i z a t i o n r a t e (v) is in direct p r o p o r t i o n to the first p o w e r o f m o n o m e r c o n c e n t r a t i o n ([M)] a n d to the square root of the initiato'r c o n c e n t r a t i o n ([I]). This kinetic b e h a v i o u r is fully consistent with the c o n v e n t i o n a l e q u a t i o n of chain p o l y m e r i z a t i o n rate in liquid phase [9]: v =kg ~ ~, [M] x/[I],
[2]
where k~, k i, k b are the respective r a t e constants of growth, initiation and breakage.
1048
S. G. MATSOYANand 1~. M. MORLYAN
The strict observance of the proportionality of v and the square root [I] confirm bimolecular breakage of reacting chains. As evidence of the breakage reaction b y interaction of polymer radicals, m a y be cited the fact that the mean coefficient of DMVEC polymerization, as can be seen from Fig. 3, is inversely proportional to the square root of initiator concentration.
n,tO -2 16
12
8
1 4
8
12
:FIG. 3. Dependence of t,he coefficient of polymerization (n) of poly-DMVEC on BP concentration: 1 - i n methanol, monomer concentration 3.81 mole/1, 80°C; 2--in bulk, 60°C; 3--in bulk, 50°C.
The absence of gel effect during polymerization is, apparently, explained b y the nature of DMVEC, the hydroxyl groups of which are capable of forming hydrogen bonds. A slight variation of the mean molecular weight of poly-DMVEC, according to the degree of conversion, (Fig. 4) also confirms the absence of the gel effect. The total activation energy of DMVEC polymerization in bulk calculated from the effective polymerization rate constant (Fig. 5a) at different temperatures, is 21.6 kcal/mole. The value found agrees in practice with the activation energy (20.9 kcal/mole) of polymerization of DMVEC in methanol solution (Fig. 5b). The effective activation energy of polymerizatio n , according to equation (2) is E=I/2Ei+(E~--I/2Eb), where E i, Eg, E b are the activation energies of elementary reactions of initiation (for B P E i - 30 kcal/mole), growth and breakage of chains respectively. The value of (Eg--1/2Eb)for DMVEC is 6.6 kcal/mole, which satisfactorily agrees with the value of 4-7 kcal/mole for m a n y monomers in radical polymerization [9]. Thus, all the data in the investigation of polymerization of DMVEC are quite consistent with the mechanism of polymerization of conventional monomers. From these data it can be assumed that the initial step, the addition of the growing radical to the first monomer molecule, is the limiting stage in the complex
Cyclic polymerization and copolymerization--XXIII
1049
m e c h a n i s m of D M V E C chain growth. The remaining stages of chain g r o w t h {dimerization, isomerization and eyclization) r e p r e s e n t reactions t a k i n g place r a p i d l y with a low e n e r g y threshold, caused b y the stabilization of the initial allene radical. 5+logk
M,1o"|
18
15( ~ 10 5
14 1
b
12
[ I ., 40 80 Depth o f convepsion , %
280
I 2-90
300 1/T , 103
FIG. 4 FId. 5 Fi6'. 4. Dependence of the molecular weight (M) of poly-DMVEC on the degree of conversion: 1 - a t 80°C; 2--at 70°C. FI(~. 5. Dependence of the logarithm of effective polymerization rate constant (log k) of DMVEC on --in bulk; b --in methanol solution.
l/T: a
CONCLUSIONS
(1) Radical p o l y m e r i z a t i o n of d i m e t h y l v i n y l e t h i n y l c a r b i n o l in bulk and in m e t h a n o l solution has been i n v e s t i g a t e d in the range of 50-80°; the effect o f initial m o n o m e r a n d initiator c o n c e n t r a t i o n on the rate of p o l y m e r i z a t i o n has been studied. (2) I t has been f o u n d t h a t , u n d e r the conditions studied, high-molecular weight linear-cyclic p o l y m e r s form, for which the relation between intrinsic viscosity a n d molecular weight takes the form: [~]= 1.99 × 10 -~ x M ° % (3) I t was established t h a t the overall r a t e of p o l y m e r i z a t i o n is in d i r e c t p r o p o r t i o n to the first power o f m o n o m e r c o n c e n t r a t i o n and to the square r o o t of initiator c o n c e n t r a t i o n ; u p to the m a x i m u m degree of m o n o m e r conversion (80-85%) a u t o - a c c e l e r a t i o n of p o l y m e r i z a t i o n (gel effect) was n o t observed. I t has been shown t h a t the m e a n coefficient of p o l y m e r i z a t i o n is in inverse p r o p o r t i o n to the square r o o t of initiator concentration. (4) I t was f o u n d t h a t , for d i m e t h y l v i n y l e t h i n y l c a r b i n o l , value is 6.6 kcal/mole which is in satisfactory a g r e e m e n t with the m e c h a n i s m of chain p o l y m e r i z a t i o n of conventional monomers. E. SEMERE
(E.~--I/2E~)
Translatedby
REFERENCES
1. 2. 3. 4.
C. PRICE and F. MCKEON, J. Polymer Sci. 41: 445, 1959 I. N. NAZAROV and L. N. TEREKHOVA, Izv. Akad. Nauk SSSR, Otd. khim. n. 66, 1950 I. P. BERDINSKIKI'I, Klei i skleivaniye. (Glues and Glueing.) Mashgiz, 1952 H. DYKSTRA, J. Amer. Chem. Soc. 56: 1625, 1934
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YE. V. SHARKOVA et al.
5. 'S. G. MATSOYAN, N. M. MORLYAN and E. Ts. GEVORKYAN, Auth. Cert. U.S.S.R. 155605, 1961 6. S. G. MATSOYAN, N. M. MORLYAN and E. Ts. GEVORKYAN, Auth. Cert. U.S.S.R. 155606, 1961 7. S. G. MATSOYAN, N. M. MORLYAN and A. A. SAAKYAN, Izv. Akad. Nauk ArmSSR, Khim. 11. 15: 405, 1962 8. S. G. MATSOYAN and N. M. MORLYAN, Izv. Akad. Nauk. ArmSSR, Khim. n. 16: 347, 1963 9. Kh. S. BAGDASARYAN, Teoriya radikal'noi polimcrizatsii. (Theory of Radical Polymerization.) Moscow, 1959
STUDY OF CONVERSIONS, ANALOGOUS TO POLYMERIZATION OF CELLULOSE AND POLYGLYCIDYL METHACRYLATE GRAFT COPOLYMER*t YE. F. SHARKOVA, A. D. VIRNIK and Z. A. ROGOVIN t Moscow Textile Institute
(Received 2 J u l y 1963)
ONE of the chief methods of modifying the properties of cellulose materials is synthesis of cellulose graft copolymers. Considerable interest is attracted to the synthesis of cellulose graft copolymers containing reactive groups in the macromolecule; by using these groups it is possible to modify further the cellulose graft copolymers. This paper is devoted to the investigation of conversions of cellulose and polyglycidyl methacrylate ~ graft copolymer which are analogous to polymerization. The presence of epoxy groups in the cellulose and polyglycidylmethacrylate graft copolymer makes it possible to effect several conversions analogous to polymerization. We studied some of the possible analogous conversions of cellulose and polyglycidyl methacrylate graft copolymer. We investigated the reaction of cellulose and polyglycidyl methacrylate graft copolymer with sodium bisulphite, sodium sulphite, ammonia, monoethanolamine and diethylamine. * Vysokomol. soycd. 6: No. 5, 951-956, 1964. ~f 150th paper from the series "Study of the structure and properties of cellulose and its derivatives". Experimental part of the study carried out with the participation of K. K. Shevarov. § After this paper had been completed, a report was published on the work of Kurosaki and Ivakura, who synthesized cellulose and polyglycidyl methaerylate graft copolymer and, as a result of the interaction of epoxy groups of this copolymer with the aminogroups of the dye, obtained a synthetic coloured fibre [1].