Lamellar compounds of graphite with alkali metals as catalysts for polymerization of organocyclosiloxanes

Synthetic Metals, 4 (1982) 331 - 343

331

LAMELLAR COMPOUNDS OF GRAPHITE WITH ALKALI METALS AS CATALYSTS FOR POLYMERIZATION OF ORGANOCYCLOSILOXANES

M. E. VOLTIN, YU. N. NOVIKOV and V. M. KOPYLOV

Institute of Organoelement Compounds, Academy of Sciences USSR, Moscow (U.S.S.R.) L. M. KHANANASHVILI and Ts. B. KAKULIYA

The Tbilissi State University, Tbilissi (U.S.S.R.) (Received March 11, 1981)

Summary The polymerization of octamethylcyclotetrasiloxane,hexamethylcyclotrisiloxane, 1,3,5-trimethyl-l,3,5-triphenylcyclotrisiloxane and 1,3,5-trimethyl-l,3,5-tris(3,3,3-trifluoropropyl)cyclotrisiloxane in the presence of lamellar graphite-alkali metal compounds has been investigated. Negatively charged graphite layers rather than alkali metal atoms are supposed to constitute the active polymerization centers. A cyclic structure is proposed for the polymers.

Introduction

In lamellar graphite-alkali metal compounds (LGCs) negatively charged carbon layers of graphite alternate with monolayers of partly ionized atoms of an alkali metal [ 1 ]. This fact renders their electronic structure similar to that of aromatic anion radicals [cf. l(b)] whose catalytic activity in the polymerization of organic monomers is well known [2, 3]. This analogy, with the possibility of controlling the value of the negative charge on the carbon layer either by introducing various alkali metals or various amounts of an alkali metal, the strictly fixed distance between carbon layers of graphite in LGCs, as well as the insolubility of these compounds, attracted researchers' attention as potential heterogeneous catalysts for anionic polymerization of olefin monomers and ethylene oxide [4 - 10]. In our opinion, the use of these LGCs as catalysts for polymerization of organocyclosiloxanes is of great interest. A large number of basic-type compounds that are catalytically active in the polymerization of organocyclosiloxanes are known [11]. In common, 0379-6779/82/0000-0000/$02.75

© Elsevier Sequoia/Printed in The Netherlands

332

these catalysts enter a polymeric chain thereby forming "an alive p o l y m e r " having active end groups. The presence of such groups considerably reduces the thermal stability of polyorganosiloxanes since they catalyze a depolymerization reaction at relatively low temperatures [ 12]. The use of LGCs as catalysts in this reaction aroused reasonable expectations that the polymers thus formed would n o t contain any alkali metal. The present paper reports the results of a study on the polymerisation o f octamethylcyclotetrasiloxane (D4), hexamethylcyclotrisiloxane (D3); 1,3,5-trimethyl-l,3,5-triphenylcyclotrisiloxane (A3) and 1,3,5-trimethyl1,3,5-tris(3',3',3'-trifluoropropyl)cyclotrisiloxane (F3) in the presence o f K and Li LGCs*.

Experimental All the operations were conducted under an atmosphere of dry, pure argon. D 3 and D4 were dried b y boiling over calcium hydride for 8 h and then distilled in an argon flow. We used natural graphite with an ash content o f less than 0.1% in our experiments.

Synthesis of CsK [16 ] Graphite was charged into a three-necked flask provided with a stirrer and dried under flowing argon for 2 h at a temperature o f 150 °C. Next, potassium was added in small portions under intensive stirring at 100 110 °C. The resultant mixture was stirred for 1 h, cooled, and transferred to a Schlenk flask. A similar procedure was used for the preparation of LGC with Li [ 17 ]. The synthesis conditions and the results of an X-ray investigation of the catalysts are reported in Table 1.

TABLE 1 Charges of reactants, conditions for synthesis, and results of X-ray analyses of K-LGC and Li-LGC LGC

CsK C24K C36K C6Li

Weighed a m o u n t of an alkali metal

Weight of graphite

(g)

(g)

1.63 0.94 0.47 0.19

4.0 6.94 5.21 2.00

*Ic is the identity p e r i o d ; l c is the

Temp. (°C)

Time (h)

Stage

110 170 230 200

1 3 3.5 0.5

I II III I

t h i c k n e s s of a filled layer.

*Our preliminary results were published in refs. 13 - 15.

Ic*

I'c*

(A)

(A)

5.40 8.75 12.10 3.71

5.40 5.40 5.40 3.71

333 Polymerization o f D4

A three-necked flask provided with a stirrer and a tap for the supply of argon was evacuated and heated in a burner flame to remove moisture. Next, 10 g {3.37 × 10 -2 mole) o f D4 were placed into the flask under an argon flow together with a weighed a m o u n t of LGC with K, and the resultant mixture was heated at 115 °C. U p o n completion of the reaction, portions (each of 2 g) of the reaction mixture were taken and each dissolved in 100 ml of dry toluene ( in case of Fs in ethyl acetate). One of the solutions was deactivated with MesSiC1 (0.001%), filtered, and the p o l y m e r precipitated with methanol (in the case o f Fs, with toluene). The polymers were dried for 24 h at a temperature of 70 °C and a pressure of 1.5 mmHg. Similarly, polymerization of D3 (Table 3), A3 (Table 4) and F3 (Table 5) was carried out. The reaction mixture was analysed b y liquid-gas chromatography (Chromosorb W, phase SE-30 -- 15%).

Discussion o f results

The polymerization o f organocyclosiloxanes was carried o u t en bloc at a temperature of 60 to 160 °C. As seen in Tables 2 - 5, LGC with K is active for the polymerization of D3, D4, A 3 and F 3 to form ultimately polyorganosiloxanes with a molecular mass of 105 - 106. LGCs with Li do not catalyze the polymerization of D4 up to a temperature of 160 °C when the reaction is carried o u t en bloc and in polar solvents (for instance, in THF). Neither is A3 polymerized en bloc b y LGCs with Li up to 110 °C, b u t an increase in the temperature up to 160 °C results in the formation of a cross-linked polymer. Polymerization o f D3 does not proceed in non-polar solvents (benzene) up to 80 °C, b u t in the presence of T H F the reaction proceeds easily, even at room temperature, to form polydimethylsiloxane with a yield o f 94% after 6 h (Table 3). As distinct from other cyclosiloxanes, F3 is readily polymerized in the presence o f Li LGC (Table 5). The results obtained demonstrate that the reaction capacity of organosiloxanes increases with an increase in the acceptor properties of radicals found at a silicon atom. This shows that LGCs with alkali metals act as nucleophilic catalysts. The difference observed in the activities o f K-LGC and Li-LGC could be due to the different values of the negative charges in the carbon lattices in these compounds. A study o f the effect of the reaction time, catalyst composition and concentration on the p o l y m e r yield and on their molecular mass revealed that there is much in c o m m o n b e t w e e n the catalytic action of alkali metal LGCs and that of conventional nucleophflic catalysts. Thus, in the presence o f LGC, the polymerization is reversible and equilibrated. The catalyst

334 TABLE 2 Block polymerization of D 4 in the presence of K-LGC* Catalyst

MDJMcat**

Reaction time

Yield of polymer (%)

(h)

CsK

C~K

C~K

45.5 75.9 151.8 303.6 151.8 151.8 151.8 78.7 157.5 315.0 648.1 157.5 157.5 157.5 79.5 199.4 401.2 802.4 265.4 265.4 265.4

6 6 6 6 2 4 8 6 6 6 6 2 4 8 6 6 6 6 2 6 8

deact,

nondeact.

70 68 76 80 56 80 78 74 73 75 75 50 80 83 80 76 79 72 62 82 65

72 68 72 77 54 78 73 74 71 75 72 50 80 83 78 76 76 70 63 82 62

[77]***

M X 10 - 5 t

deact,

nondeact,

deact,

nondeact.

0.78 1.77 2.07 2.72 1.20 2.54 2.22 1.33 1.99 3.05 3.15 2.25 1.28 1.40 1.90 1.70 2.35 1.68 2.03 1.54 1.53

0.82 1.68 2.06 2.56 1.15 2.45 2.07 1.33 1.93 3.20 3.12 2.05 1.20 1.40 1.95 1.75 2.40 1.77 1.90 1.70 1.58

1.87 4.56 5.41 7.28 2.99 6.76 5.84 3.35 5.18 8.24 8.54 5.92 3.21 3.81 4.93 4.37 6.21 4.31 5.30 3.92 3.35

1.98 3.98 5.38 6.34 2.86 6.50 4.84 3.35 4.73 8.69 8.45 5.35 2.99 2.99 5.07 4.51 6.35 4.56 4.93 4.65 4.03

*10 g of D4; polymerization temperature 115 °C. **Molar monomer-to-catalyst ratio. ***Toluene, 25 °C. t A s calculated for [77] = 0.11 × 1 0 - 4 M ~92.

composition and the molar ratio between the m o n o m e r and the catalyst have virtually no effect on the final yield o f the polymers which corresponds in all the cases to an equilibrium yield {Tables 2 - 5). Moreover, the molecular mass o f the polymers at an equal monomer-to-catalyst ratio is scarcely dependent on the catalyst composition {Tables 2, 4, 5). At the same time, notable differences in the behaviour of various K-LGCs compared with that o f conventional nucleophilic catalysts are observed. The molecular mass o f a polymer, as a rule, is little dependent on the molar monomer-to-catalyst ratio, whereas in the case of conventional nucleophilic catalysts it increases with an increase in the molar monomer-tocatalyst ratio. Other peculiar features in the catalytic behaviour o f alkali metal LGCs become apparent during investigation o f the dependence between the molecular mass of polymers v s . the polymerization time of D4 in the presence of C24 K a n d C36 K. It is known that in the case of conventional nucleophilic catalysts, the molecular mass o f a polymer increases with

335

0"~

C~ ¢.O

CO O'a

I I ,,~ t ~ I I ~

X

I ~ l l l l ~

¢D

r..-

oo

I I~l~l

Io

..,re

I

~

oo

eo eo c o eo C,-~ c,,~ ~

r--

*

cq

oo-x-

co-x-

.,.~ .x-

Q;

I I 1 ~ ~ ---... * ..L,

X .r-I

ee~

c~

oo0_~

~, ~ o c~ °o~

,,.o ~N

c~

F-Q p.-.

E-,

r~

r~

336 TABLE 4 Polymerization of A 3 in the presence of K-LGC (A 3 -- 10 g, 60 °C) Catalyst

MAJMcat* Time (h)

C8K

C24K

C36K

33.1 55.2 110.3 220.2 110.3 110.3 110.3 53.4 114.5 267.3 535.2 100.2 100.2 100.2 57.7 115.5 192.5 462.5 288.7 288.7 288.7 288.7

2 2 2 2 0.5 1 4 2 2 2 2 0.5 1 4 2 2 2 2 0.5 1 2 4

Yield of polymer (%) deact,

nondeact.

69 72 71 74 73 74 76 74 73 71 73 75 72 73 73 72 72 71 73 72 73 68

76 75 71 74 74 72 75 73 73 72 75 74 72 73 73 70 71 69 72 69 74 70

M

[77 ] **

X

10 -5***

deact,

nondeact,

deact,

nondeact.

4.30 3.35 3.58 4.05 3.04 3.30 2.24 3.60 2.50 3.45 3.20 3.20 2.70 2.85 2.60 3.95 3.12 2.50 2.50 3.20 3.70 2.45

4.26 3.25 5.59 3.98 3.04 3.25 2.18 3.55 2.45 3.50 3.30 3.10 2.65 2.75 2.55 4.00 3.12 2.50 2.45 3.15 3.60 2.40

14.56 10.57 11.52 13.49 9.34 10.37 6.31 11.60 7.26 10.98 9.97 9.97 8.02 8.60 7.64 13.06 9.65 7.26 7.26 9.97 12.01 7.08

14.39 10.17 11.55 13.19 9.34 10.17 6.10 11.39 7.08 11.19 10.37 9.58 7.83 8.21 7.45 13.27 9.65 7.26 7.08 9.77 11.60 6.90

*Molar ratio A3-to-catalyst. **Determined in toluene at 25 °C. ***As calculated for [77] = 0.67 × 10 -4 M {~78.

an i n c r e a s e in t h e d e g r e e o f c o n v e r s i o n o f a m o n o m e r , w h e r e a s in t h e p r e s e n c e o f C24K a n d Ca6K t h e m o l e c u l a r mass o f p o l y d i m e t h y l s i l o x a n e s is a p p r e c i a b l y h i g h e r at a 50 - 60% c o n v e r s i o n ( f o r 2 h) t h a n at an 80% c o n v e r s i o n o f a m o n o m e r o b t a i n a b l e d u r i n g 6 h ( T a b l e 2). T h e a b o v e d e p e n d e n c e s suggest a c o n s i d e r a b l e d i f f e r e n c e in t h e m e c h anisms o f action e x e r t e d b y alkali m e t a l LGCs and b y c o n v e n t i o n a l nucleophilic catalysts. O n e o f t h e p o s s i b l e r e a s o n s a c c o u n t i n g f o r such a d i f f e r e n c e m a y r e s i d e in t h e f a c t t h a t it is n o t a l k a l i m e t a l a t o m s , b u t r a t h e r n e g a t i v e l y c h a r g e d carbon layers o f graphite t h a t constitute the active p o l y m e r i z a t i o n centres of c y c l o s i l o x a n e s . I f t h i s is t h e case, an a l k a l i m e t a l s h o u l d n o t pass i n t o a polymer. In o r d e r t o c l a r i f y t h e p r o b l e m ( w h e t h e r p o t a s s i u m passes f r o m t h e c a t a l y s t i n t o a p o l y m e r o r n o t ) t h e s t a b i l i t y o f t h e s e p o l y m e r s was c h e c k e d

337 TABLE 5 Polymerization of F 3 in the presence of Li-LGC* Catalyst

C6Li

CzsLi

MA3/Mcat*

3.7 5.9 13.4 17.8 26.7 53.5 50.3 75.5 150.9

Yield of polymer

(%)

deact,

nondeact.

68 86 80 82 88 86 73 72 82

63 82 78 78 84 80 70 70 78

[~]***

M X 10 - 5 t

deact,

nondeact,

deact,

nondeact.

0.43 0.51 0.98 1.10 0.83 1.08 0.90 0.98 0.96

0.43 0.62 0.85 1.00 0.86 1.05 0.86 1.00 0.99

2.39 3.17 9.24 11.16 7.04 10.83 8.03 9.24 8.93

2.39 4.36 7.31 9.55 8.03 10.35 7.46 9.55 9.39

*F 3 9.5 g, 160 °C, 5.5 h. **Molar ratio F3-to-catalyst. ***As determined in ethyl acetate at 25 °C. t A s calculated for [17] = 2.25 × 10 - 4 M ~61.

during boiling of their diluted solutions in toluene (in the case of F 3 in ethyl acetate). It is known [12] that under such conditions polyorganosiloxanes produced using conventional nucleophilic catalysts and containing active end groups are completely depolymerized. For the sake of comparison, the molecular masses and yields of polymers deactivated by trimethylchlorosilane and reprecipitated by methanol (for F 3 with toluene) (a deactivated polymer) were determined, as compared with polymers which were not treated with trimethylchlorosilane, but were dissolved in toluene (in the case of F3 in ethyl acetate) (2 - 3% solution), boiled for 2 h, and finally precipitated with methanol (in the case of F3 with toluene) (a nondeactivated polymer). As may be seen in Tables 2 - 5, the yields and molecular masses of deactivated and non-deactivated polymers differ little and, consequently, the polymers contain no K-siloxanolate end groups. It should be noted that upon heating, an alkali metal LGC itself catalyzes depolymerization of polyorganosiloxanes. Thus, boiling a solution of 2 g of polydimethylsiloxane in 50 ml of toluene in the presence of 0.01 g of CsK results in the complete depolymerization of the polymer. These data indicate that even if potassium is present in a polymer, its amount is insignificant. This fact is corroborated by the results of a thermogravimetric analysis of polymers and following their analysis for potassium content. As seen in Fig. 1, the TGA curves of deactivated and non
338

~oo

~x x

8o

6o ,Z

\

~ 2o

×

zoo

~oo

6~o

~oo ~'c

Fig. 1. Weight loss vs. temperature for polyorganosiloxanes; x, non-deactivated polymer; A, deactivated polymer: 1, [(CH3)2SiO ] n produced in the presence of (CH3)3SiOK; 2, [(CF3CH2CH2)(CH3)SiO ] n produced in the presence of C6Li; 3, [(CH3)2SiO ] n produced in the presence of C24K; 4, [(CH3)(C6Hs)SiO] n produced in the presence of CsK.

for 80%. The X-ray fluorescence analysis of a non-deactivated and nonreprecipitated polydimethylsiloxane with a molecular mass of 5.38 × 105 revealed that its potassium content did n o t exceed 10 -4 mass %. This value is a b o u t 100 times less than that which may be expected in a linear polymer having the same molecular mass and K-siloxanolate end groups. Hence, all the data obtained point to the fact that the polymers produced from A3, F3, D4 and D3, when catalyzed b y means o f K-LGC, do not contain active K-siloxanolate groups. Some interesting features o f this reaction were found on investigating the dependence between the conversion of D4 and the polymer yield vs. time when carrying out the reaction e n b l o c in the presence of C24K. In order to discover the dependences in the polymerization process, samples were taken in which the yield of polymer was determined from the dry residue, and the degree o f conversion o f D4 b y gas-liquid chromatography. The degree of conversion o f D4 was determined using b o t h an "external standard" (when cumene used as a standard agent was introduced into selected samples) and an "internal standard" (when dodecane used as a standard agent was introduced into a reaction flask prior to the onset of the reaction). Since the reaction takes place in the absence of solvents, in the case o f an "external standard" a decrease in the D4 concentration will take place only when a polymer occurs in solution, and the yield of the polymer in this case throughout the entire reaction should be close to the degree o f conversion o f D4. As seen from Fig. 2 (curve 1), when the reaction is carried o u t with an "external standard", the polymerization process comprises a long induction period (100 - 130 min) during which the conversion o f D 4 reaches only some 5 - 10%, followed b y a rapid polymerization process, which, in 90 min, achieves an 80% degree of conversion. The yield o f the p o l y m e r is close to the degree of conversion of D4.

339

40O

~0

~0

ZO

0

40

~0

~20

460

20o

2ko

28o

3ZO

Fig. 2. Dependence between conversion of D 4 and the yield of polymer vs. time during polymerization of D 4 in the presence of C24K. Polymerization using an "external standard" (cumene) ; 1, conversion of D 4; 2, yield of polymer. Polymerization using an "internal standard" (dodecane); (3, conversion of D4; 4, yield o f polymer).

The induction period could be explained by the fact that in the initial polymerization stages, adsorption of D 4 takes place on the catalyst and the polymer thus formed has not yet passed into the volume. We confirmed this assumption by carrying out a reaction using an "internal standard". Since, in this method, a standard is present in the reaction mixture from the very beginning, this factor allows observation of the conversion of D 4 even when the polymer does not pass into the volume. Indeed, as seen from Fig. 2 (curve 3), D4 enters the reaction immediately, but the polymer starts passing into the volume later (see Fig. 2, curve 4). Hence, the difference between curves 3 and 4 reflects the amount of polymer associated with the catalyst. The structure of macromolecules of this polymer and the mechanism of polymerization of organocyclosiloxanes with the aid of K-LGC are of extreme importance. Considering the nature of the catalysts used, the thoroughness of drying and the purification of the monomer, together with the fact that the reaction was carried out in pure, dry argon, one can reasonably assume that blocking and chain-breaking impurities were practically absent in the reaction system. At any rate, all the data available agree with the assumption on the cyclic structure of'macromolecules. Indeed, only in this case would a polymer be free from potassium, not be depolymerized by boiling in a toluene solution, and behave, under thermogravimetric analysis conditions, in substantially the same manner as a linear polymer having blocked end groups. The formation of cyclic macromolecules may take place according to the schemes shown in Fig. 3 (for the D4 case). According to scheme I, the reaction proceeds on the surface of the LGC, while according to scheme II, the reaction takes place between the carbon layers of graphite. What is common to both schemes is an initiation step due to the transfer of electrons from the graphite layers to cyclosiloxane, resulting in the formation of a dianion. Chain growth takes place by insertion of D4 between

340

K ÷ K+ K+ K+

K + K+ K+ K+

K+ K+ K+ K+ -

I

-

]

I 4"(MezSiO)4

+ (MezSiO)4 ~, (MezSiO)3

/\

-

-SiMez

-0

_

K+ K+ K+ K+

K + K+ K* K + K ÷ K+ K* K+

,/SiMe2 (Me2SiO)3 ~'-0

I

+ nlMe2SiO)4 '

+n(Me2SiO)4

(Me2SiO)4n+3

J,

/\ -0

-SiMe~

K+ K+ K+ K+

K+ K + K + K+ _ _ K + K+ K + K+

,,~SiMez ( MezSiO)4n+3 "-0

+(Me2SiO)4

/(Me2SiO)3 \

+(MezSiO]4 1 -

_

-0 -$iMe2 Me2Si--O K+ K+ K+ K+ Me2Si--0 I I I /~SiMez + 0I SiMe 2 K4" -K÷ K÷ K-+ + 0 S i M e 2 (Me2SiO)3 K+ K+ K+ K+ \ / ~-0 \ / _ _ (MezSiO)4n+2 [MezSiO)4n+z

Scheme I

Scheme II

Fig. 3. Polymerization schemes of D 4 in the presence o f C24K and C8K.

anion and graphite and, incidentally, according to scheme I, a cycle should be pre-adsorbed on the surface o f the catalyst, while according to scheme II, it should be incorporated between the graphite layers. In both cases, the transfer o f a chain may take place by formation o f a cyclopolymer and its desorption from the catalyst, while active groups remain on the heterogeneous catalyst. We tried to choose between the two schemes by carrying out the reaction in the presence o f naphthalene. If the polymerization proceeds according to scheme I (on the LGC surface) the introduction o f naphthalene would either slow the process because o f its better adsorption on the LGC (as shown by Panajotov and Rashkov for the polymerization of styrene on K-LGC [4, 18] ) or it would not influence the polymerization rate if cyclosiloxanes were adsorbed better than naphthalene. If the reaction proceeded according to scheme II (in the interplane spaces o f LGC), naphthalene would accelerate the process if it penetrated between the graphite lattices and widened them thereby facilitating the access of cyclosiloxane.

341

As seen in Fig. 4, the introduction of naphthalene has no effect on the polymerization rate of D4 in the presence of CsK. This shows that the polymerization of D4 takes place on the surface of CsK and cyclosiloxane is adsorbed on its surface better than naphthalene. A different picture emerges in the case of C24K. As seen in Fig. 5, the introduction of naphthalene accelerates the polymerization of D4 in the presence of C24K. In this case, the polymerization of D4 proceeds according to scheme II (in the interlayer space of graphite). The facts are in agreement with our observations on naphthalene insertion into C24K in nonpolar solvents, with the formation of the ternary c o m p o u n d C24.26K(NP)0.5, and the absence of naphthalene insertion into CsK under the same conditions (the synthesis and structure of the K-graphite-naphthalene compound will be published in Synthetic Metals). It should be noted that the K-graphite-naphthalene ternary compound is the most active D4 polymerization catalyst compared with C24K and C24K + naphthalene. A change in the polymerization reaction mechanism in the presence of naphthalene (e.g., the formation of potassium ~00.

~" 8oi

_.A

g 60

.

zo

60

~oo

~

i40

:

YEO

i

~2o

i

Z6o ~ime rain

Fig. 4. Conversion of D 4 vs. time dependence during polymerization of D4 in the presence of CsK and naphthalene.

¢O6

~0

z~o 2o

Fig. 5. Conversion of D 4 vs. time dependence during polymerization of D4 in the presence of C24K and naphthalene: 1, without naphthalene - - ~ ; Mnaphth./Mcat. -- 3.5:1 - - x ; 2, MnaphthJMcat. = 20; 3, using K-LGC -- naphthalene LGC of formula C28(C10Hs)~5K.

342

naphthalenide, as was found in THF [ 19] ) appears unlikely, since thermogravimetric analysis results demonstrate that in the presence of naphthalene any polymers formed do not contain appreciable amounts of potassium. The possibility of a reaction taking place in the interplanar space of graphite is also confirmed following a study of the introduction of D3 into CmK. Da was introduced by two techniques. In the first, a solution of D 3 in heptane was mixed with C24K under an argon atmosphere for 30 h at 20 °C. In the second technique (introduction from the gas phase), D 3 and C24K were placed into two different Schlenk flasks connected by glass tubing, following which the system was left under vacuum for 3 - 5 days at 20 or 60 °C. X-ray examination of the samples produced by each technique revealed that the initial C~K lines either disappeared or that their intensity was considerably weakened, and that new lines appeared corresponding to new structures having an identity period of 15.3 and 19.1 (Table 6). These data demonstrate that the introduction of Da into C ~ K is accompanied by an increase in the thickness of the layer, being filled to 12 and/or 15.6 h . Hence, polymerization of organocyclosiloxanes with alkali metal LGC results in the formation of polymers having a probable cyclic structure, the process being capable of taking place both on the surface of the LGC and in the interior. TABLE 6 The results o f X-ray analysis o f the products formed by penetration o f D 3 into C24K I

d

00l

Phase

I

(A) w vw m vw s m s

15.50 9.51 8.76 7.62 5.13 4.73 4.37

d

001

Phase

I II II I

C24C

(A) 001 002 001 002 003 004 002

I II C24K I I II C24K

vs

3.818

vs vs

3.164 3.079

004 005 006 005

s w

2.921 2.181

003 004

C24K

I phase I c = 15.3 A. II p h a s e / c = 19.0 A.

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343 8 9 10 11 12 13 14 15 16 17 18 19

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