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Cationic copolymerization of vinylalkyl ethers with cyclic ethers
Cationic copolymerization of vinylalkyl ethers with cyclic ethers
1203
equation in the initial stages of crystallization (up to about t----t1/2). In the final stage of crystallization deviation from the theoretical equation occurs as a result of secondary crystallization. Translated by E. O. PHILLIPS REFERENCES 1. Y. E. LUCAS, P. H. JOHNSON, L. B. W A K E F I E L D and B. L. JOHNSON, Ind. Engng. Chem. 41: 1626, 1949 2. J. T. MAYNARD and W. E. MOCHEL, J. Polymer Sci. 13: 235, 1954 3. R. M. MURRAY and J. D. DETENBER, Rubber Chem. and Technol. 34: 668, 1961 4. A. N. GENT, J. Polymer Sci. A3: 3787, 1965 5. V. GRMELA and L. MEGARSKAYA, K a u ch u k i rezina, No. 9, 31, 1966 6. I. K~)SSLER and L. SVOB, J. Polymer Sci. 54: 17, 1961 7. C. H A U D R E T and M. MORIN, Rev. gen. caoutchouc 42: 395, 1965 8. N. B E K K E D A H L , J. Res. Natl. Bur. Standards 43: 145, 1949 9. M. AVRAMI, J. Chem. Phys. 7: 1103, 1939 10. L. B. MORGAN, J. Appl. Chem. 4: 160, 1954 11. L. MANDELKERN, Kristallizatsiya polimerov (Crystallization of Polymers). Izd. " K h i m i y a " , 1966 (Russian translation) 12. J. N. HAY, J. Polymer Sci. A3: 433, 1965 13. J. H. MAGILL, Polymer 3: 43, 1962 14. G. Ye. NOVIKOVA and O. N. TRAPEZNIKOVA, Kauchuk i rezina, No. 3, 1, 1964 15. A. I. MAREI, N. P. KUZNETSOV and G. Ye. NOVIKOVA, Kauchuk i rezina, No. 3, 41, 1965 16. P. W. ALLEN, Trans. F a r a d a y Soc. 48: 1178, 1952
CATIONIC COPOLYMERIZATION OF VINYLALKYL ETHERS WITH CYCLIC ETHERS* •
V. A. P o OMARENKO, A. M. KHOMUTOV and A. P. ALIMOV
N. D. Zelinskii Organic Chemistry Institute, U.S.S.R. Academy of Scienees
(Received 16 February 1967) THE problem of the copolymerization of monomers belonging to different classes of organic compound (vinyl derivatives, cyclic ethers, aldehydes, ketones, etc.) is of great scientific and practical interest. There are papers in the literature about the copolymerization of unsaturated compounds with cyclic ethers and formals [1-9]. Information about the copolymerization of vinylalkyl ethers with cyclic ethers is limited to reports of the attempts by Japanese authors to obtain copolymers from vinylisobutyl ether with fl-propiolactone [7] and with 3,3-bis-(chloromethyl)oxacyclobutane [10]. * Vysokomol. soyed. AI0: No. 5, 1038-1045, 1968.
V. A. PONO~RE~KO et al.
1204
I he aim of the present work was to study the copolymerization reaction between vinyl-n-butyl ether (VBE) and epichlorhydrin (ECH) and tetrahydrofurane (THF) in the presence of the catalyst system triethylaluminium-water (TEAwater). I t is known t h a t ECI-I polymerizes in the presence of the catalyst T E A water [11]. The catalyst system TEA-water-cocatalyst is used for the polymerization of T H F [12] and vinylalkyl ethers [13]; it is possible to use ECH as cocatalyst [12, 14]. The copolymerization of VBE and ECH under the action of the TEA-water catalyst at 0°C in bulk takes place violently in the initial period, and the reaction mixture becomes warm. The effect of the catalyst concentration on the yield, intrinsic viscosity and composition of the product obtained under these conditions was studied. The results of the experiments shown in Table 1, indicate t h a t a reduction in catalyst concentration leads to an increase in the yield and intrinsic viscosity of the product obtained, and does not influence its composition. The quest!on of the formation of eopolymers rather than a mixture of homopolymers in the cases mentioned required special experiments to be carried out. The method of selective extraction, which is widely used for this purpose, was employed by us as an indication of the fact t h a t copolymers had been formed. Heptane and acetone were used as solvents, since the VBE polymer dissolves in heptane and does not dissolve in acetone, and the ECH polymer dissolves in acetone and not in heptane. The reliability of the selective extraction method in this case was checked by the quantitative separation of a synthetically prepared mixture of VBE and ECH homopolymers (see Table 2). The results of the selective extraction of the product obtained from the copolymerization of VBE and ECH in the presence of the TEA-water catalyst in bulk at 0°C showed t h a t it was not a mixture of two homopolymers (see Table 3, results of extraction of specimen :No. 25). The fractions separated during selective extraction TABLE
1. E F F E C T
OF THE
CATALYST CONCENTRATION
(TEA-wATER,
VBE A~D ECI-I (Total amount of the monomers, 5 g; molar ratio of the initial monomers, 1 : 1; duration of polymerization, 48 hr; polymerization temperature, 0°C). :MOLAR R & T I O
Catalyst concentration, mole% 2.5 1.25 0.5 0.25*
1 : 0"5) O~
THE
COPOLYMEI~IZATION OF
[~/]in benzene at 30°C, dl/g
Yield of copolymer, % I
1.6 37.2 61.8 65.0
* Specimen No. 25.
Average con- Composition centration of of copolymer, mole% chlorine in copolymer,% VBE ECH
i
0.83 1.07 1.25
11.50 10.96 11.92
68.4 69.8 67.2
31.6 30.2 32.8
Cationic copolymerization of vinylalkyl ethers with cyclic ethers
1205
contain units from both the monomers; this is indisputable evidence for the formation of the copolymer. So t h a t the copolymerization of V B E and E C H in the presence of the T E A water catalyst should take place at a regulated rate, the reaction was carried out in solution. H e p t a n e was used as solvent. The effect of the total concentration of the monomers in heptane on the copolymerization of V BE and E C H
TABLE
2. SELECTIVE ~IXTURE
EXTRACTION OF VBE
OF THE SYNTHETICALLY
AND ECH
PREPARED
HOMOPOLYMERS
(0.1404 g poly-VBE* and 0.1477 g poly-ECHt taken) Fraction
Yield of i fraction, [
Soluble in heptane Residue, soluble in acetone
g
Composition of Chlorine fraction, mole ~o concentration, ~o VBE ECH
0.1375
0"61
0.1440
38.25
98.3 --
1.7 100.0
* 1~Iol. wt. 450,000. t Mol. wt. 100,000.
was studied at 0°C. As m a y be seen from Table 4, a reduction in the total monomer concentration somewhat reduces the yield and intrinsic viscosity, and increases the concentration of V B E units in the copolymer. The results of the selective extraction of the product obtained from the copolymerization of V B E and EC H in solution at 0°C indicate t h a t it is also not a mixture of homopolymers (see Table 3, results of the extraction of specimen No. 45). The dependence of the composition of V B E - E C H copolymers on the composition of the initial mixture was studied at low and also at high degrees of conversion of the monomers. The copolymerization was carried out in heptane at 0°C. Table 5 shows the results of the experiments on the copolymerization of VBE and EC H in the presence of the T E A - w a t e r catalyst at low degrees of conversion. As m a y be seen from the data presented in Table 5, V BE is v e r y much more active t h a n E C H in the initial period of the reaction: in all cases, even with an excess of E C H in the reaction mixture, the copolymers are enriched with VBE units as compared with the composition of the initial mixture. The results of the selective extraction of the V B E - E C H copolymer obtained at low transformations with an excess of E C H in the initial mixture show t h a t the copolymer does not contain either the E C H tfomopolymer or fractions containing predominantly E C H units (see Table 3, results of the extraction of specimen No. 41). At high degrees of conversion as well, enrichment of the copolymers with V B E units as compared with the composition of the initial mixture takes place (Table 6). In carrying out the copolymerization of V BE and T H F in the presence of
V. A. PO~TOM.~EZCKO et al.
1206
i
r~
o
~1 oo
r~
~
0
o
~1
>
t r~
oo ~.~ ~.~
0 oo
0 r~
N
"F~o~ ~~~c ~,~® !I~ N r~ 0 oo
N oo
N N
aaa
r~ N
~4 m
o
~2 m~
Cationic copolymerization of vinylalkyl ethers with cyclic ethers
1207
T A B L E 4. E F F E C T O1~ T H E CONCENTRATIOI~ OF T H E MONOMERS ON T H E COPOLYMERIZATION OF
VBE
AND
ECH
I N T H E P R E S E N C E OF T H E CATALYST SYSTEM T E A - w A T E R
(MOLAR RATIO
1 : 0.5)
(Molar ratio of the initial monomers, 1 : 1; solvent, n-heptane; q u a n t i t y of catalyst, 0.25 molc~o of the total q u a n t i t y of monomers; t o t a l q u a n t i t y of the monomers, 5 g; polymerization temperature, 0°C) Concentration of monomers in heptane, vol.%
Duration of reaction, hr
48
100" 50 40 30 20¢
73 96 96 96
Yield of copolymers, ~/o
Average in benzene chlorine conat 30°C, dl/g centration,
[el
65"0 66.2 58.4 54.8 50.4
%
11.92 12"34 11.97 9.72 6"33
1"25 1"24 0"73 0-8 0"74
Composition of copolymer, mole °/o VBE]
ECH
67'2 66.1 67"1 73.2 82.4
32.8 33-9 32.9 26.8 17-6
* Specimen No. 25. Specimen No. 45.
the catalyst system TEA-water, ECH was used as cocatalyst, since neither V B E [15] n o r T H F [12] 10olymerizes u n d e r t h e a c t i o n o f t h e T E A - w a t e r c a t a lyst (with a molar ratio TEA-water >1). The copolymerization was carried out i n b u l k a t 20°C. T h e r e l a t i o n s h i p b e t w e e n t h e c o m p o s i t i o n o f t h e c o p o l y m e r s and the composition of the initial mixture was studied at low and high degrees of conversion of the monomers. The results of the experiments are shown in T a b l e s 7 a n d 8.
T A B L E 5. COPOLYMERIZATION OF
VBE
AND ~ C H
AT LOW D E G R E E S OF CON-
V E R S I O N OF THE I N I T I A L MONOMERS, I N T H E PRESENCE
OF T H E
CATALYST
TEA-wATER (MOLARRATIO, 1 : 0"5) (Quantity of catalyst, 1 mole ~o of the total q u a n t i t y of monomers; concent r a t i o n of monomers in heptane, 50 vol.~o; t o t a l quantity of the monomers, 5 g; polymerization temperature, 0°C)
Molar ratio VBE : ECH
Yield of copolymer,
~o
Average chlorine concentration in copolymer, %
Composition of copolymer, mole~o VBE
80 : 20 60 : 40 40 : 60 20 : 80* * Specimen I~o. 41.
9"3 19.1 30 23-9
1.64 2.43 3.32 8.35
95.4 93.2 90.7 76.8
ECH 4.6 6.8 9.3 23-2
1208
al.
V . A . P O N O M A R E N K O et
TABLE 6.
COPOLYMERIZATION
OF
VBE
AND
ECH
AT HIGH
DEGREES
OF CON-
V E R S I O N OF T H E I N I T I A L M O N O M E R S I N T H E P R E S E N C E O F T H E C A T A L Y S T
TEA-
W A T E R (MOLA/t R A T I O , 1 : 0.5)
( Q u a n t i t y of catalyst, 0.25 mole~o; c o n c e n t r a t i o n of the m o n o m e r s in heptane, 20 vol. %; t o t a l q u a n t i t y of the monomers, 2.5 g; p o l y m e r i z a t i o n t e m p e r a t u r e , 0°C; p o l y m e r i z a t i o n duration, 150 hr) i
[~] in benYield of Molar ratio zene at icopolymer, VBE : ECH % 30°C, dl/g
58.4 48"5 47"9
75 : 25 50 : 50 25:75
Mw *
1"48 0"98 0"62
Composition of c o p o l y m e r mole %
A v e r a g e chlorine concentration in copolymer, ~o
240,000 190,000 150,000
1"9 6"75 23.0
VBE
ECH
94"6 81.3 38.2
5"4 18.7 61.8
* Molecular weight determined by sedimentation in a n ultracentrifuge.
TABLE
7. C O P O L Y M E R I Z A T I O N OF
VBE
AND
THF
AT SMALL D E G R E E S OF CONVER o
S I O N O F T H E I N I T I A L M O N O M E R S I N T H E P R E S E N C E OF T H E C A T A L Y S T S Y S T E M T E A -
WATER-ECI~ ( M O L A R RATIO, 1 : 0'5 : 1) ( Q u a n t i t y of the c y t a l y s t system, 0-25 mole % of t o t a l q u a n t i t y of the monomers; t o t a l q u a n t i t y of t h e monomers, 5 g; p o l y m e r i z a t i o n t e m p e r a t u r e , 20°C)
Molar ratio VBE : THF
80 60 40 20
TABLE
8.
Yield of copolymer, %
: 20 : 40 : 60 : 80
Composition of t h e m i x t u r e of u n r e a c t e d monomers, wt. °/o
Composition of copolymer, m o l e %
VBE
VBE
21-2 21-6 17.5 6.4
C O P O L Y M E R I Z A T I O N OF
81.7 60.5 42 23.3
VBE
AND
THE INITIAL MONOMERS IN THE PRESENCE
THF
OF T H E
THF 18.3 39.5 58 76.7
AT H I G H
THF
98-4 96-7 76.9 67.2
DEGREES
CATALYST
SYSTEM
1.6 3"3 23-1 32- 8
OF
CONVERSION
OF
TEA-wATER-ECH
(MOLAR RATIO, 1 : 0'5 : 1) ( Q u a n t i t y of catalyst system, 0.25 mole°/o of t o t a l q u a n t i t y of the monomers; t o t a l q u a n t i t y of m o n o m e r s 5 g; p o l y m e r i z a t i o n t e m p e r a t u r e , 20°C; p o l y m e r i z a t i o n duration, 150 hr) Yield of [~/] in bencopolymer, zene at % 30°C, dl/g
Molar ratio VBE : THF
Mw*
A v e r a g e carbon concentration in copolymer,
%
Composition of copolymer, mole % VBE
THF
L
75 : 25 50 : 50 25 : 75
31 43 54.5
1-6 1.15 1.66
280,000 230,000
71.06 70.16 68.37
* Molecular weight determined by sedimentation in a n ultracentrifuge.
77.1 57.8 25.2
22.9 42.2 74.8
Cationic copolymerization of vinylalkyl ethers with cyclic ethers
1209
As in the case of the copolymerization of VBE and ECH, VBE is considerably more active t h a n T H F in the initial period of the reaction; in all cases, even with an excess of T H F in the reaction mixture, the copolymers at low degrees of conversion are enriched with VBE units as compared with the composition of the initial mixture (see Table 7). However, this enrichment is less than during the copolymerization of VBE and ECH (see Figure). A very slight enrichment of the copolymers with VBE units as compared with the composition of the initial mixture occurs when the copolymerization of VBE and T H F is carried out to high degrees of conversion (see Table 8). To show t h a t copolymers of VBE and T H F had been formed, extraction of the products obtained was carried out with heptane. The T H F homopolymer is insoluble in heptane, as distinct from the VBE homopolymer which dissolves in heptane. The results of the extraction with heptane of the product obtained from the copolymerization of VBE and T H F in the presence of the catalyst system T E A - w a t e r - E C H at a molar ratio of the initial monomers equal to 1 : 1 show t h a t the product is not a mixture of the two homopolymcrs (see Table 9). The fraction soluble in heptane contains units from both the monomers, in evidence of the formation of the V B E - T H F copolymer. TABLE
9. EXTRACT~O~OF VBE AND THF COPOLYMERSWITHHEPTANE
Fraction
Soluble in heptane Insoluble in heptane
Concentra- Average tion of carbon fraction, concentrawt.Oo tion, % 88.5 11.5
69.94 67.46
Composition of fraction, mole °/o VBE 53.5 11.3
THF 46.5 88.7
I t m a y be seen from the data given t h a t a considerable enrichment of the copolymer with VBE units takes place in the initial period during the copolymerization of VBE with E C t t or THF. This shows t h a t VBE is more active than ECH or T H F during copolymerization. As the active monomer (VBE) is used up during the course of the reaction, the concentration of the cyclic ether increases in the reaction mixture, and this leads to an increase in the concentration of ECH or T H F units in the eopolymer at high degrees of transformation. However in this case also the copolymers are enriched in VBE units as compared with the composition of the initial mixture. I t also follows from the results obtained (see Figure and Tables 6 and 8) t h a t T H F is more active than ECH with respect to VBE. This m a y be explained by the fact t h a t the basicity of T H F is higher than t h a t of ECH [16]. On the basis of the results obtained and the data in the literature, a possible mechanism for the copolymerization of vinylalkyl ethers with simple
V. A. PON0~RENX0
1210
et al.
cyclic ethers m a y be p r e s e n t e d in the following way. S i n c e n e i t h e r V B E [15] nor T H F [12] polymerize in the presence of the c a t a l y s t s y s t e m T E A - w a t e r a t a molar ratio T E A - w a t e r >1), the act o f initiation is e v i d e n t l y c o n n e c t e d ml, [
60 1 ~
J
20
~/
40
60
i
60
80 M,, mole%
Dependence of the copolymer composition on the composition of the initial monomer mixture at low degrees of conversion for the monomer pairs: 1--VBE-ECH; 2--VBE-THF. M1 (mole~o) is the concentration of VBE in the initial mixture (abscissa axis): ml is the concentration of VBE units in the eopolymer. with the interaction between E C H a n d the T E A - w a t e r c a t a l y s t w i t h the form a t i o n of an ion pair, which is also the initiator for the c o p o l y m e r i z a t i o n reaction between the vinylalkyl e t h e r a n d the simple cyclic ether. T h e cross chain p r o p a g a t i o n reaction which leads to the f o r m a t i o n of t h e c o p o l y m e r takes place when the molecule of the simple cyclic e t h e r is a d d e d on to the growing p o l y m e r chain having a vinylalkyl e t h e r u n i t at its end, leading to the f o r m a t i o n of an o x o n i u m ion: CH~ + +/I ~ CHa--CHa- + CH~--CH--CH~CI-~ ~ CH,--CH--O 0/C,H.
I \ 0C4Hck-CH
\ 0/
I
CH2C1 or when a molecule of the v i n y l a l k y l e t h e r is a d d e d on to the growing p o l y m e r chain having a cyclic ether unit at each end. T h e o x o n i u m ion is t r a n s f o r m e d during ring scission into a c a r b o n i u m ion, a n d a molecule of the v i n y l a l k y l ether adds on to it:
--
CH~
CH2--1
I
/
'
"',,
r
~ C--O®
I A-\,!
CH
i_
I
CH2C1
I
A- CH I
I
I
]
CHIC1
I
~ C - - O ~ H ~ - - C H A - + C H 2 = C H ---)
I
~H,C1
+
--~ ~ C--O--CH~--CH A-
I OC4H9 ] + ----* ~ C--O--CH2--CH--CH2--CH AI I ~)C,H, CHIC1
I
CH~CI
Cationic eopolymerization of vinylalkyl ethers with cyclic ethers
1211
I n the light of recent w o r k [17], one c a n n o t exclude the possibility of the f o r m a t i o n o f block or g r a f t e o p o l y m e r s between V B E a n d simple cyclic ethers b y m e a n s of chain t r a n s f e r t h r o u g h the p o l y m e r with r u p t u r e . T h e i n t e n s i t y o f this reaction should increase m a r k e d l y t o w a r d s the e n d of the p o l y m e r i z a t i o n process w h e n t h e c o n c e n t r a t i o n o f p o l y m e r chains has increased a n d t h e chain p r o p a g a t i o n reaction has p r a c t i c a l l y ceased [17]. I n this way, the c o p o l y m e r s o b t a i n e d a t low a n d high degrees of conversion of the initial m o n o m e r s m a y differ s u b s t a n t i a l l y in their structures. Thus, when the c o p o l y m e r i z a t i o n o f V B E a n d E C t t is carried o u t to high degrees of conversion in bulk, t h e c o p o l y m e r o b t a i n e d contains a fraction insoluble in h e p t a n e a n d acetone c o n t a i n i n g units from b o t h the m o n o m e r s , a n d also a fraction insoluble in organic solvents, evidently h a v i n g a n e t w o r k s t r u c t u r e (see Table 3, results o f t h e e x t r a c t i o n o f specimen No. 25). The V B E - E C H c o p o l y m e r o b t a i n e d at low degrees o f conversion does n o t contain these fractions (see Table 3, results of the e x t r a c t i o n of specimen No. 41). I n all p r o b a b i l i t y this c o p o l y m e r is statistical, because the chain transfer reaction t h r o u g h the p o l y m e r with r u p t u r e should t a k e place only with a low i n t e n s i t y in t h e initial period. T h e question of t h e role of t h e chain transfer reaction t h r o u g h the p o l y m e r with r u p t u r e during the copolymerization of V B E a n d E C H in the presence of the T E A - w a t e r c a t a l y s t will be discussed b y us in a n o t h e r c o m m u n i c a t i o n .
EXPERIMENTAL Preparation of the catalyst and purification of the monomers. The metho d of preparing the TEA-water catalyst (molar ratio 1 : 0.5) and the purification of VBE and ECH have been described previously [14]. The THF was dried with potassium hydroxide, calcium chloride and with metallic sodium, and was boiled and distilled over metallic sodium and degassed in vacuo. The THF was stored in an ampoule in a vacuum manifold over a potassium-sodium alloy. The purity of the monomers was monitored by gas-liquid chromatography, n-Heptane was dried with calcium chloride and metallic sodium and boiled and distilled over metallic sodium. After this, the heptane was degassed and stored in an ampoule in an vacuum manifold over a potassium-sodium alloy. Copolymerization. The eopolymerization was carried out in sealed ampoules. A determined quantity of a solution of the TEA-water catalyst in heptane (concentration of the TEA-water catalyst in heptane, 1 mole/L) was added into the ampoule, which had been purged with argon, from a Sehlenk apparatus. The ampoule was connected to the vacuum manifold, the contents of the ampoule were degassed and the solvent (in the case of VBEECH vapour)or the eocatalyst (for VBE-THF vapour) and the comonomers were reeondensed into the ampoule. The ampoule was sealed off from the manifold and placed in a thermostat. After a certain time, the ampoule was opened, the copolymer dissolved in benzene and precipitated with methanol containing a small quantity of hydrochloric acid, and dried gn vacuo to constant weight. The composition of the VBE-ECH copolymers was calculated from the results of a chlorine analysis. The composition of the VBE-THF copolymers obtained at the maximum degrees of conversion of the monomers was calculated from the results of a carbon analysis. The composition of the VBE-THF eopolymers obtained at low degrees of conversion was calculated from the results of a determination of the composi-
1212
V. A. POI~IOYiXRENKOet al.
tion of the mixture of unreacted monomers by means of gas-liquid chromatography. The intrinsic viscosity was determined in benzene at 30°C using a viscometer with a constant head. The weight-average molecular weight of the copolymers obtained was determined b y sedimentation in an ultracentrifuge. The selective extraction of the copolymers with organic solvents was carried out b y the method used for the extraction of vinylalkyl ether polymers with m(~thylethylketone [18].
CONCLUSIONS
(1)
I n t h e p r e s e n c e of t h e t r i e t h y l a l u m i n i u m - w a t e r c a t a l y s t s y s t e m , h i g h m o l e c u l a r w e i g h t c o p o l y m e r s of v i n y l - n - b u t y l e t h e r w i t h e p i c h l o r h y d r i n or t e t r a h y d r o f u r a n e are o b t a i n e d . (2) I t h a s b e e n e s t a b l i s h e d t h a t v i n y l - n - b u t y l e t h e r is m o r e a c t i v e t h a n epic h l o r h y d r i n or t e t r a h y d r o f u r a n e i n t h e c o p o l y m e r i z a t i o n r e a c t i o n . Translated by G. F. MODLE~r REFERENCES 1. R. MERTON, Fed. Germ. Rep. Pat. 1083055, 1.960: referred to by J. F U R U K A W A and T. SAEGUSA, Polimerizatsiya al'degidov i okisei (Polymerization of Aldehydes and Oxides). (Russian translation). Peace Publishers, 381-383, 1965 2. U. K. Pat. 866323, 1961, loe. cit., 1o. 384 3. W. KERN, H. CHERDRON and V. JAACKS, Angew. Chem. 73: 177, 1961 4. T. TSURUTA and R. FUJIO, Makromol. Chem. 64: 219, 1963 5. A. A. DURGARYAN and P. M. BEGINYAN, Vysokomol. soyed. 5: 28, 1963 (Translated in Polymer Sci. U.S.S.R. 4: 4, 630, 1963) 6. M. OKADA Y. YAMASHITA and Y. ISHII, Makromol. Chem. 80: 196, 1964 7. S. AOKI, K. FUJISAWA, T. OTSU and M. IMOTO, Bull. Chem. Soc. J a p a n 38: 1928, 1965 8. S. AOKI, K. FUJISAWA, T. OTSU and M. IMOTO, Bull. Chem. Soe. J a p a n 39: 729, 1966 9. T. TSUDA and Y. YAMASHITA, Makromol. Chem. 86: 304, 1965 10. S. AOKI, HARITA, T. OTSU and M. IMOTO, Bull. Chem. Soe. J a p a n 38: 1922, 1965 11. E. VANDERBERG, U.K. Pat. 898306, 1962: referred to by J. F U R U K A W A and T. SAEGUSA, Polimerizatsiya al'degidov i okisei (Polymerization of Aldehydes and Oxides) (Russian translation). Peace Publishers, 381-383, 1965 12. T. SAEGUSA, T. IMAI and J. FURUKAWA, Makromol. Chem. 65: 60, 1963 13. T. SAEGUSA, T. IMAI and J. FURUKAWA, Makromol. Chem. 64: 224, 1963 14. A. P. ALIMOV, A. M. KHOMUTOV and V. A. PONOMARENKO, Vysokomol. soyed. B10: 68, 1968 (Not translated in Polymer Sci. U.S.S.R.) 15. T. SAEGUSA, T. IMAI and J. FURUKAWA, Makromol. Chem. 79: 207, 1964 16. S. SEARLES and T. TAMRES, J. Amer. Chem. Soc. 73: 3704, 1951 17. N. S. YENIKOLOPYAN, V. I. IRZHAK and B. A. ROZENBERG, Uspekhi khimii 35: 714, 1966 18. M. F. SHOSTAKOVSKII, A. M. KHOMUTOV and A. P. ALIMOV, Izv. Akad. N a u k SSSR, seriya khimich., 1848, 1964
1203
equation in the initial stages of crystallization (up to about t----t1/2). In the final stage of crystallization deviation from the theoretical equation occurs as a result of secondary crystallization. Translated by E. O. PHILLIPS REFERENCES 1. Y. E. LUCAS, P. H. JOHNSON, L. B. W A K E F I E L D and B. L. JOHNSON, Ind. Engng. Chem. 41: 1626, 1949 2. J. T. MAYNARD and W. E. MOCHEL, J. Polymer Sci. 13: 235, 1954 3. R. M. MURRAY and J. D. DETENBER, Rubber Chem. and Technol. 34: 668, 1961 4. A. N. GENT, J. Polymer Sci. A3: 3787, 1965 5. V. GRMELA and L. MEGARSKAYA, K a u ch u k i rezina, No. 9, 31, 1966 6. I. K~)SSLER and L. SVOB, J. Polymer Sci. 54: 17, 1961 7. C. H A U D R E T and M. MORIN, Rev. gen. caoutchouc 42: 395, 1965 8. N. B E K K E D A H L , J. Res. Natl. Bur. Standards 43: 145, 1949 9. M. AVRAMI, J. Chem. Phys. 7: 1103, 1939 10. L. B. MORGAN, J. Appl. Chem. 4: 160, 1954 11. L. MANDELKERN, Kristallizatsiya polimerov (Crystallization of Polymers). Izd. " K h i m i y a " , 1966 (Russian translation) 12. J. N. HAY, J. Polymer Sci. A3: 433, 1965 13. J. H. MAGILL, Polymer 3: 43, 1962 14. G. Ye. NOVIKOVA and O. N. TRAPEZNIKOVA, Kauchuk i rezina, No. 3, 1, 1964 15. A. I. MAREI, N. P. KUZNETSOV and G. Ye. NOVIKOVA, Kauchuk i rezina, No. 3, 41, 1965 16. P. W. ALLEN, Trans. F a r a d a y Soc. 48: 1178, 1952
CATIONIC COPOLYMERIZATION OF VINYLALKYL ETHERS WITH CYCLIC ETHERS* •
V. A. P o OMARENKO, A. M. KHOMUTOV and A. P. ALIMOV
N. D. Zelinskii Organic Chemistry Institute, U.S.S.R. Academy of Scienees
(Received 16 February 1967) THE problem of the copolymerization of monomers belonging to different classes of organic compound (vinyl derivatives, cyclic ethers, aldehydes, ketones, etc.) is of great scientific and practical interest. There are papers in the literature about the copolymerization of unsaturated compounds with cyclic ethers and formals [1-9]. Information about the copolymerization of vinylalkyl ethers with cyclic ethers is limited to reports of the attempts by Japanese authors to obtain copolymers from vinylisobutyl ether with fl-propiolactone [7] and with 3,3-bis-(chloromethyl)oxacyclobutane [10]. * Vysokomol. soyed. AI0: No. 5, 1038-1045, 1968.
V. A. PONO~RE~KO et al.
1204
I he aim of the present work was to study the copolymerization reaction between vinyl-n-butyl ether (VBE) and epichlorhydrin (ECH) and tetrahydrofurane (THF) in the presence of the catalyst system triethylaluminium-water (TEAwater). I t is known t h a t ECI-I polymerizes in the presence of the catalyst T E A water [11]. The catalyst system TEA-water-cocatalyst is used for the polymerization of T H F [12] and vinylalkyl ethers [13]; it is possible to use ECH as cocatalyst [12, 14]. The copolymerization of VBE and ECH under the action of the TEA-water catalyst at 0°C in bulk takes place violently in the initial period, and the reaction mixture becomes warm. The effect of the catalyst concentration on the yield, intrinsic viscosity and composition of the product obtained under these conditions was studied. The results of the experiments shown in Table 1, indicate t h a t a reduction in catalyst concentration leads to an increase in the yield and intrinsic viscosity of the product obtained, and does not influence its composition. The quest!on of the formation of eopolymers rather than a mixture of homopolymers in the cases mentioned required special experiments to be carried out. The method of selective extraction, which is widely used for this purpose, was employed by us as an indication of the fact t h a t copolymers had been formed. Heptane and acetone were used as solvents, since the VBE polymer dissolves in heptane and does not dissolve in acetone, and the ECH polymer dissolves in acetone and not in heptane. The reliability of the selective extraction method in this case was checked by the quantitative separation of a synthetically prepared mixture of VBE and ECH homopolymers (see Table 2). The results of the selective extraction of the product obtained from the copolymerization of VBE and ECH in the presence of the TEA-water catalyst in bulk at 0°C showed t h a t it was not a mixture of two homopolymers (see Table 3, results of extraction of specimen :No. 25). The fractions separated during selective extraction TABLE
1. E F F E C T
OF THE
CATALYST CONCENTRATION
(TEA-wATER,
VBE A~D ECI-I (Total amount of the monomers, 5 g; molar ratio of the initial monomers, 1 : 1; duration of polymerization, 48 hr; polymerization temperature, 0°C). :MOLAR R & T I O
Catalyst concentration, mole% 2.5 1.25 0.5 0.25*
1 : 0"5) O~
THE
COPOLYMEI~IZATION OF
[~/]in benzene at 30°C, dl/g
Yield of copolymer, % I
1.6 37.2 61.8 65.0
* Specimen No. 25.
Average con- Composition centration of of copolymer, mole% chlorine in copolymer,% VBE ECH
i
0.83 1.07 1.25
11.50 10.96 11.92
68.4 69.8 67.2
31.6 30.2 32.8
Cationic copolymerization of vinylalkyl ethers with cyclic ethers
1205
contain units from both the monomers; this is indisputable evidence for the formation of the copolymer. So t h a t the copolymerization of V B E and E C H in the presence of the T E A water catalyst should take place at a regulated rate, the reaction was carried out in solution. H e p t a n e was used as solvent. The effect of the total concentration of the monomers in heptane on the copolymerization of V BE and E C H
TABLE
2. SELECTIVE ~IXTURE
EXTRACTION OF VBE
OF THE SYNTHETICALLY
AND ECH
PREPARED
HOMOPOLYMERS
(0.1404 g poly-VBE* and 0.1477 g poly-ECHt taken) Fraction
Yield of i fraction, [
Soluble in heptane Residue, soluble in acetone
g
Composition of Chlorine fraction, mole ~o concentration, ~o VBE ECH
0.1375
0"61
0.1440
38.25
98.3 --
1.7 100.0
* 1~Iol. wt. 450,000. t Mol. wt. 100,000.
was studied at 0°C. As m a y be seen from Table 4, a reduction in the total monomer concentration somewhat reduces the yield and intrinsic viscosity, and increases the concentration of V B E units in the copolymer. The results of the selective extraction of the product obtained from the copolymerization of V B E and EC H in solution at 0°C indicate t h a t it is also not a mixture of homopolymers (see Table 3, results of the extraction of specimen No. 45). The dependence of the composition of V B E - E C H copolymers on the composition of the initial mixture was studied at low and also at high degrees of conversion of the monomers. The copolymerization was carried out in heptane at 0°C. Table 5 shows the results of the experiments on the copolymerization of VBE and EC H in the presence of the T E A - w a t e r catalyst at low degrees of conversion. As m a y be seen from the data presented in Table 5, V BE is v e r y much more active t h a n E C H in the initial period of the reaction: in all cases, even with an excess of E C H in the reaction mixture, the copolymers are enriched with VBE units as compared with the composition of the initial mixture. The results of the selective extraction of the V B E - E C H copolymer obtained at low transformations with an excess of E C H in the initial mixture show t h a t the copolymer does not contain either the E C H tfomopolymer or fractions containing predominantly E C H units (see Table 3, results of the extraction of specimen No. 41). At high degrees of conversion as well, enrichment of the copolymers with V B E units as compared with the composition of the initial mixture takes place (Table 6). In carrying out the copolymerization of V BE and T H F in the presence of
V. A. PO~TOM.~EZCKO et al.
1206
i
r~
o
~1 oo
r~
~
0
o
~1
>
t r~
oo ~.~ ~.~
0 oo
0 r~
N
"F~o~ ~~~c ~,~® !I~ N r~ 0 oo
N oo
N N
aaa
r~ N
~4 m
o
~2 m~
Cationic copolymerization of vinylalkyl ethers with cyclic ethers
1207
T A B L E 4. E F F E C T O1~ T H E CONCENTRATIOI~ OF T H E MONOMERS ON T H E COPOLYMERIZATION OF
VBE
AND
ECH
I N T H E P R E S E N C E OF T H E CATALYST SYSTEM T E A - w A T E R
(MOLAR RATIO
1 : 0.5)
(Molar ratio of the initial monomers, 1 : 1; solvent, n-heptane; q u a n t i t y of catalyst, 0.25 molc~o of the total q u a n t i t y of monomers; t o t a l q u a n t i t y of the monomers, 5 g; polymerization temperature, 0°C) Concentration of monomers in heptane, vol.%
Duration of reaction, hr
48
100" 50 40 30 20¢
73 96 96 96
Yield of copolymers, ~/o
Average in benzene chlorine conat 30°C, dl/g centration,
[el
65"0 66.2 58.4 54.8 50.4
%
11.92 12"34 11.97 9.72 6"33
1"25 1"24 0"73 0-8 0"74
Composition of copolymer, mole °/o VBE]
ECH
67'2 66.1 67"1 73.2 82.4
32.8 33-9 32.9 26.8 17-6
* Specimen No. 25. Specimen No. 45.
the catalyst system TEA-water, ECH was used as cocatalyst, since neither V B E [15] n o r T H F [12] 10olymerizes u n d e r t h e a c t i o n o f t h e T E A - w a t e r c a t a lyst (with a molar ratio TEA-water >1). The copolymerization was carried out i n b u l k a t 20°C. T h e r e l a t i o n s h i p b e t w e e n t h e c o m p o s i t i o n o f t h e c o p o l y m e r s and the composition of the initial mixture was studied at low and high degrees of conversion of the monomers. The results of the experiments are shown in T a b l e s 7 a n d 8.
T A B L E 5. COPOLYMERIZATION OF
VBE
AND ~ C H
AT LOW D E G R E E S OF CON-
V E R S I O N OF THE I N I T I A L MONOMERS, I N T H E PRESENCE
OF T H E
CATALYST
TEA-wATER (MOLARRATIO, 1 : 0"5) (Quantity of catalyst, 1 mole ~o of the total q u a n t i t y of monomers; concent r a t i o n of monomers in heptane, 50 vol.~o; t o t a l quantity of the monomers, 5 g; polymerization temperature, 0°C)
Molar ratio VBE : ECH
Yield of copolymer,
~o
Average chlorine concentration in copolymer, %
Composition of copolymer, mole~o VBE
80 : 20 60 : 40 40 : 60 20 : 80* * Specimen I~o. 41.
9"3 19.1 30 23-9
1.64 2.43 3.32 8.35
95.4 93.2 90.7 76.8
ECH 4.6 6.8 9.3 23-2
1208
al.
V . A . P O N O M A R E N K O et
TABLE 6.
COPOLYMERIZATION
OF
VBE
AND
ECH
AT HIGH
DEGREES
OF CON-
V E R S I O N OF T H E I N I T I A L M O N O M E R S I N T H E P R E S E N C E O F T H E C A T A L Y S T
TEA-
W A T E R (MOLA/t R A T I O , 1 : 0.5)
( Q u a n t i t y of catalyst, 0.25 mole~o; c o n c e n t r a t i o n of the m o n o m e r s in heptane, 20 vol. %; t o t a l q u a n t i t y of the monomers, 2.5 g; p o l y m e r i z a t i o n t e m p e r a t u r e , 0°C; p o l y m e r i z a t i o n duration, 150 hr) i
[~] in benYield of Molar ratio zene at icopolymer, VBE : ECH % 30°C, dl/g
58.4 48"5 47"9
75 : 25 50 : 50 25:75
Mw *
1"48 0"98 0"62
Composition of c o p o l y m e r mole %
A v e r a g e chlorine concentration in copolymer, ~o
240,000 190,000 150,000
1"9 6"75 23.0
VBE
ECH
94"6 81.3 38.2
5"4 18.7 61.8
* Molecular weight determined by sedimentation in a n ultracentrifuge.
TABLE
7. C O P O L Y M E R I Z A T I O N OF
VBE
AND
THF
AT SMALL D E G R E E S OF CONVER o
S I O N O F T H E I N I T I A L M O N O M E R S I N T H E P R E S E N C E OF T H E C A T A L Y S T S Y S T E M T E A -
WATER-ECI~ ( M O L A R RATIO, 1 : 0'5 : 1) ( Q u a n t i t y of the c y t a l y s t system, 0-25 mole % of t o t a l q u a n t i t y of the monomers; t o t a l q u a n t i t y of t h e monomers, 5 g; p o l y m e r i z a t i o n t e m p e r a t u r e , 20°C)
Molar ratio VBE : THF
80 60 40 20
TABLE
8.
Yield of copolymer, %
: 20 : 40 : 60 : 80
Composition of t h e m i x t u r e of u n r e a c t e d monomers, wt. °/o
Composition of copolymer, m o l e %
VBE
VBE
21-2 21-6 17.5 6.4
C O P O L Y M E R I Z A T I O N OF
81.7 60.5 42 23.3
VBE
AND
THE INITIAL MONOMERS IN THE PRESENCE
THF
OF T H E
THF 18.3 39.5 58 76.7
AT H I G H
THF
98-4 96-7 76.9 67.2
DEGREES
CATALYST
SYSTEM
1.6 3"3 23-1 32- 8
OF
CONVERSION
OF
TEA-wATER-ECH
(MOLAR RATIO, 1 : 0'5 : 1) ( Q u a n t i t y of catalyst system, 0.25 mole°/o of t o t a l q u a n t i t y of the monomers; t o t a l q u a n t i t y of m o n o m e r s 5 g; p o l y m e r i z a t i o n t e m p e r a t u r e , 20°C; p o l y m e r i z a t i o n duration, 150 hr) Yield of [~/] in bencopolymer, zene at % 30°C, dl/g
Molar ratio VBE : THF
Mw*
A v e r a g e carbon concentration in copolymer,
%
Composition of copolymer, mole % VBE
THF
L
75 : 25 50 : 50 25 : 75
31 43 54.5
1-6 1.15 1.66
280,000 230,000
71.06 70.16 68.37
* Molecular weight determined by sedimentation in a n ultracentrifuge.
77.1 57.8 25.2
22.9 42.2 74.8
Cationic copolymerization of vinylalkyl ethers with cyclic ethers
1209
As in the case of the copolymerization of VBE and ECH, VBE is considerably more active t h a n T H F in the initial period of the reaction; in all cases, even with an excess of T H F in the reaction mixture, the copolymers at low degrees of conversion are enriched with VBE units as compared with the composition of the initial mixture (see Table 7). However, this enrichment is less than during the copolymerization of VBE and ECH (see Figure). A very slight enrichment of the copolymers with VBE units as compared with the composition of the initial mixture occurs when the copolymerization of VBE and T H F is carried out to high degrees of conversion (see Table 8). To show t h a t copolymers of VBE and T H F had been formed, extraction of the products obtained was carried out with heptane. The T H F homopolymer is insoluble in heptane, as distinct from the VBE homopolymer which dissolves in heptane. The results of the extraction with heptane of the product obtained from the copolymerization of VBE and T H F in the presence of the catalyst system T E A - w a t e r - E C H at a molar ratio of the initial monomers equal to 1 : 1 show t h a t the product is not a mixture of the two homopolymcrs (see Table 9). The fraction soluble in heptane contains units from both the monomers, in evidence of the formation of the V B E - T H F copolymer. TABLE
9. EXTRACT~O~OF VBE AND THF COPOLYMERSWITHHEPTANE
Fraction
Soluble in heptane Insoluble in heptane
Concentra- Average tion of carbon fraction, concentrawt.Oo tion, % 88.5 11.5
69.94 67.46
Composition of fraction, mole °/o VBE 53.5 11.3
THF 46.5 88.7
I t m a y be seen from the data given t h a t a considerable enrichment of the copolymer with VBE units takes place in the initial period during the copolymerization of VBE with E C t t or THF. This shows t h a t VBE is more active than ECH or T H F during copolymerization. As the active monomer (VBE) is used up during the course of the reaction, the concentration of the cyclic ether increases in the reaction mixture, and this leads to an increase in the concentration of ECH or T H F units in the eopolymer at high degrees of transformation. However in this case also the copolymers are enriched in VBE units as compared with the composition of the initial mixture. I t also follows from the results obtained (see Figure and Tables 6 and 8) t h a t T H F is more active than ECH with respect to VBE. This m a y be explained by the fact t h a t the basicity of T H F is higher than t h a t of ECH [16]. On the basis of the results obtained and the data in the literature, a possible mechanism for the copolymerization of vinylalkyl ethers with simple
V. A. PON0~RENX0
1210
et al.
cyclic ethers m a y be p r e s e n t e d in the following way. S i n c e n e i t h e r V B E [15] nor T H F [12] polymerize in the presence of the c a t a l y s t s y s t e m T E A - w a t e r a t a molar ratio T E A - w a t e r >1), the act o f initiation is e v i d e n t l y c o n n e c t e d ml, [
60 1 ~
J
20
~/
40
60
i
60
80 M,, mole%
Dependence of the copolymer composition on the composition of the initial monomer mixture at low degrees of conversion for the monomer pairs: 1--VBE-ECH; 2--VBE-THF. M1 (mole~o) is the concentration of VBE in the initial mixture (abscissa axis): ml is the concentration of VBE units in the eopolymer. with the interaction between E C H a n d the T E A - w a t e r c a t a l y s t w i t h the form a t i o n of an ion pair, which is also the initiator for the c o p o l y m e r i z a t i o n reaction between the vinylalkyl e t h e r a n d the simple cyclic ether. T h e cross chain p r o p a g a t i o n reaction which leads to the f o r m a t i o n of t h e c o p o l y m e r takes place when the molecule of the simple cyclic e t h e r is a d d e d on to the growing p o l y m e r chain having a vinylalkyl e t h e r u n i t at its end, leading to the f o r m a t i o n of an o x o n i u m ion: CH~ + +/I ~ CHa--CHa- + CH~--CH--CH~CI-~ ~ CH,--CH--O 0/C,H.
I \ 0C4Hck-CH
\ 0/
I
CH2C1 or when a molecule of the v i n y l a l k y l e t h e r is a d d e d on to the growing p o l y m e r chain having a cyclic ether unit at each end. T h e o x o n i u m ion is t r a n s f o r m e d during ring scission into a c a r b o n i u m ion, a n d a molecule of the v i n y l a l k y l ether adds on to it:
--
CH~
CH2--1
I
/
'
"',,
r
~ C--O®
I A-\,!
CH
i_
I
CH2C1
I
A- CH I
I
I
]
CHIC1
I
~ C - - O ~ H ~ - - C H A - + C H 2 = C H ---)
I
~H,C1
+
--~ ~ C--O--CH~--CH A-
I OC4H9 ] + ----* ~ C--O--CH2--CH--CH2--CH AI I ~)C,H, CHIC1
I
CH~CI
Cationic eopolymerization of vinylalkyl ethers with cyclic ethers
1211
I n the light of recent w o r k [17], one c a n n o t exclude the possibility of the f o r m a t i o n o f block or g r a f t e o p o l y m e r s between V B E a n d simple cyclic ethers b y m e a n s of chain t r a n s f e r t h r o u g h the p o l y m e r with r u p t u r e . T h e i n t e n s i t y o f this reaction should increase m a r k e d l y t o w a r d s the e n d of the p o l y m e r i z a t i o n process w h e n t h e c o n c e n t r a t i o n o f p o l y m e r chains has increased a n d t h e chain p r o p a g a t i o n reaction has p r a c t i c a l l y ceased [17]. I n this way, the c o p o l y m e r s o b t a i n e d a t low a n d high degrees of conversion of the initial m o n o m e r s m a y differ s u b s t a n t i a l l y in their structures. Thus, when the c o p o l y m e r i z a t i o n o f V B E a n d E C t t is carried o u t to high degrees of conversion in bulk, t h e c o p o l y m e r o b t a i n e d contains a fraction insoluble in h e p t a n e a n d acetone c o n t a i n i n g units from b o t h the m o n o m e r s , a n d also a fraction insoluble in organic solvents, evidently h a v i n g a n e t w o r k s t r u c t u r e (see Table 3, results o f t h e e x t r a c t i o n o f specimen No. 25). The V B E - E C H c o p o l y m e r o b t a i n e d at low degrees o f conversion does n o t contain these fractions (see Table 3, results of the e x t r a c t i o n of specimen No. 41). I n all p r o b a b i l i t y this c o p o l y m e r is statistical, because the chain transfer reaction t h r o u g h the p o l y m e r with r u p t u r e should t a k e place only with a low i n t e n s i t y in t h e initial period. T h e question of t h e role of t h e chain transfer reaction t h r o u g h the p o l y m e r with r u p t u r e during the copolymerization of V B E a n d E C H in the presence of the T E A - w a t e r c a t a l y s t will be discussed b y us in a n o t h e r c o m m u n i c a t i o n .
EXPERIMENTAL Preparation of the catalyst and purification of the monomers. The metho d of preparing the TEA-water catalyst (molar ratio 1 : 0.5) and the purification of VBE and ECH have been described previously [14]. The THF was dried with potassium hydroxide, calcium chloride and with metallic sodium, and was boiled and distilled over metallic sodium and degassed in vacuo. The THF was stored in an ampoule in a vacuum manifold over a potassium-sodium alloy. The purity of the monomers was monitored by gas-liquid chromatography, n-Heptane was dried with calcium chloride and metallic sodium and boiled and distilled over metallic sodium. After this, the heptane was degassed and stored in an ampoule in an vacuum manifold over a potassium-sodium alloy. Copolymerization. The eopolymerization was carried out in sealed ampoules. A determined quantity of a solution of the TEA-water catalyst in heptane (concentration of the TEA-water catalyst in heptane, 1 mole/L) was added into the ampoule, which had been purged with argon, from a Sehlenk apparatus. The ampoule was connected to the vacuum manifold, the contents of the ampoule were degassed and the solvent (in the case of VBEECH vapour)or the eocatalyst (for VBE-THF vapour) and the comonomers were reeondensed into the ampoule. The ampoule was sealed off from the manifold and placed in a thermostat. After a certain time, the ampoule was opened, the copolymer dissolved in benzene and precipitated with methanol containing a small quantity of hydrochloric acid, and dried gn vacuo to constant weight. The composition of the VBE-ECH copolymers was calculated from the results of a chlorine analysis. The composition of the VBE-THF copolymers obtained at the maximum degrees of conversion of the monomers was calculated from the results of a carbon analysis. The composition of the VBE-THF eopolymers obtained at low degrees of conversion was calculated from the results of a determination of the composi-
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V. A. POI~IOYiXRENKOet al.
tion of the mixture of unreacted monomers by means of gas-liquid chromatography. The intrinsic viscosity was determined in benzene at 30°C using a viscometer with a constant head. The weight-average molecular weight of the copolymers obtained was determined b y sedimentation in an ultracentrifuge. The selective extraction of the copolymers with organic solvents was carried out b y the method used for the extraction of vinylalkyl ether polymers with m(~thylethylketone [18].
CONCLUSIONS
(1)
I n t h e p r e s e n c e of t h e t r i e t h y l a l u m i n i u m - w a t e r c a t a l y s t s y s t e m , h i g h m o l e c u l a r w e i g h t c o p o l y m e r s of v i n y l - n - b u t y l e t h e r w i t h e p i c h l o r h y d r i n or t e t r a h y d r o f u r a n e are o b t a i n e d . (2) I t h a s b e e n e s t a b l i s h e d t h a t v i n y l - n - b u t y l e t h e r is m o r e a c t i v e t h a n epic h l o r h y d r i n or t e t r a h y d r o f u r a n e i n t h e c o p o l y m e r i z a t i o n r e a c t i o n . Translated by G. F. MODLE~r REFERENCES 1. R. MERTON, Fed. Germ. Rep. Pat. 1083055, 1.960: referred to by J. F U R U K A W A and T. SAEGUSA, Polimerizatsiya al'degidov i okisei (Polymerization of Aldehydes and Oxides). (Russian translation). Peace Publishers, 381-383, 1965 2. U. K. Pat. 866323, 1961, loe. cit., 1o. 384 3. W. KERN, H. CHERDRON and V. JAACKS, Angew. Chem. 73: 177, 1961 4. T. TSURUTA and R. FUJIO, Makromol. Chem. 64: 219, 1963 5. A. A. DURGARYAN and P. M. BEGINYAN, Vysokomol. soyed. 5: 28, 1963 (Translated in Polymer Sci. U.S.S.R. 4: 4, 630, 1963) 6. M. OKADA Y. YAMASHITA and Y. ISHII, Makromol. Chem. 80: 196, 1964 7. S. AOKI, K. FUJISAWA, T. OTSU and M. IMOTO, Bull. Chem. Soc. J a p a n 38: 1928, 1965 8. S. AOKI, K. FUJISAWA, T. OTSU and M. IMOTO, Bull. Chem. Soe. J a p a n 39: 729, 1966 9. T. TSUDA and Y. YAMASHITA, Makromol. Chem. 86: 304, 1965 10. S. AOKI, HARITA, T. OTSU and M. IMOTO, Bull. Chem. Soe. J a p a n 38: 1922, 1965 11. E. VANDERBERG, U.K. Pat. 898306, 1962: referred to by J. F U R U K A W A and T. SAEGUSA, Polimerizatsiya al'degidov i okisei (Polymerization of Aldehydes and Oxides) (Russian translation). Peace Publishers, 381-383, 1965 12. T. SAEGUSA, T. IMAI and J. FURUKAWA, Makromol. Chem. 65: 60, 1963 13. T. SAEGUSA, T. IMAI and J. FURUKAWA, Makromol. Chem. 64: 224, 1963 14. A. P. ALIMOV, A. M. KHOMUTOV and V. A. PONOMARENKO, Vysokomol. soyed. B10: 68, 1968 (Not translated in Polymer Sci. U.S.S.R.) 15. T. SAEGUSA, T. IMAI and J. FURUKAWA, Makromol. Chem. 79: 207, 1964 16. S. SEARLES and T. TAMRES, J. Amer. Chem. Soc. 73: 3704, 1951 17. N. S. YENIKOLOPYAN, V. I. IRZHAK and B. A. ROZENBERG, Uspekhi khimii 35: 714, 1966 18. M. F. SHOSTAKOVSKII, A. M. KHOMUTOV and A. P. ALIMOV, Izv. Akad. N a u k SSSR, seriya khimich., 1848, 1964