Preparation of ordered poly/arylenesiloxane/ polymer

Breed, L. W.

Elliott, R. L.

English

NASA Technical Reports Server

I 
REPLY TO 
kTTk Oi 
'18 3 
NATIONAL AERONAUTICS AND SPACE ~ D ~ i ~ ~ S ~ ~ ~ ~ ~ ~ ~ ~  
WASHINGTON, D.C. 20546 
October 21, 3.9'90 
GP/ 'Ofr" ice  of a s s i s t a n t  General Counsa% for 
Patent Matters 
La U. S, Pa ten t  No, 8 3,444,127 ' 
https://ntrs.nasa.gov/search.jsp?R=19710001762 2020-03-17T02:36:07+00:00Z
J 
U.9. CB. 260-46.5 
a 
Poly( arylenesiloxane) polymers having the formula 
r s  r-s ii 
where Ar is an arylene group, R is a monovalent hy- 
drocarbon radical and x is a whole number from 3 
to 5 are prepared by reacting an arylenedisilanol with 
a ,cyclic siloxazane compound. These polymers show out- 
standing stability at elevated temperature, resistance to 
radiation and capability for formation into films for use 
as coatings or elastomers. 
The invention described herein was made in the per- 
formance of work under a NASA contract and is sub- 
ject to the provisions of Section 305 of the National 
Aeronautics and Space Act of 1958, Public Law 85-568 
(72 Stat. 435; 42 USC. 2457). 
BACKGROUND OF THE INVENTION 
This invention relates to poly( arylenesiloxane) poly- 
mers and more particularly to novel polp(ary1enesiloxane) 
polymers having an ordered molecular structure. 
Poly( arylenesiloxane) polymers exhibit favorable prop- 
erties for materials applications in the aerospace field, 
for example, as coatings or elastomers for use in the 
space environment. Polymers based on the presence of 
arylene groups together with the -3-0- linkage char- 
acteristic of silicones in the backbone of the repeating 
unit offer the prospect of improved stability at relative- 
ly high temperatures and resistance to radiation and 
vacuum conditions, along with many of the favorable 
properties of the 'silicones. 
Various types of poly(arylenesi1oxane) polymers have 
been synthesized by previous workers. 'Ordered polymers 
having the formula 
rR R 1 
where Z is an arylene group and R is a monovalent 
hydrocarbon radical having been prepared by condensa- 
tion of arylenedisilanols in the presence of a catalyst, 
these polymers and their process of preparation being 
the subject matter of U.S. Patent 2,562,000, issued July 
24, 1951 to Michael Sveda. &her previously known 
poly( arylenesiloxane) polymers include random arylene- 
disilanol.polydimethylsiloxane ~copolymers, as described by 
George M. Omietanski in U.S. Patent 3,187,029, block 
arylenedisilanol-polydimethylsiloxane copolymers, as dis- 
closed by Merker, Scott and Haberland, J. Polymer Si.,  
A2, 31 (1964) and random copolymers based on bis- 
(dimethylsilyl) benzene siloxane and biw( dimethylsilyl) 
phenylether siloxane units, as described by Omietanski 
in US. Patent 3,287,310. The properties of these poly- 
mers have been limited by such factors as the presence 
of long siloxane segments, which decrease their high-tem- 
5 
10 
15 
20 
25 
30 
35 
40 
45 
50 
55 
60 
65 
70 
perature stability, by the presence of long poly(ary1ene- 
siloxane) 'units, which increase the melting point and 
crystallinity and therefore hcrease their useful low tem- 
perature range, or by their random structure which tends 
to decrease high-temperature stability. 
SUMMARY OF THE INVENTION 
The novel poly(arylenesi1oxane) polymers of the 
present invention have an ordered molecular structure as 
represented by the following formula 
where Z is an arylene group, R is a monovalent hydro- 
carbon radical and x is a whole number from 3 to 5. 
Polymers having this formula are prepared by reacting 
an arylenedisilanol with a cyclic siloxazane compound. 
The ordered polymers of this invention are stable to 
a temperature of about 500" C., and they exhibit out- 
standing resistance to radiation, along with other favor- 
able properties such as film-forming capability and 
elastomeric characteristics. 
DIESCRIPTIION OF THE PREFERRED 
EMBODIMENTS 
The arylene group, represented by Z in the tormula 
given above for the polymers of the present invention, 
can be a single phenylene ring structure such as m- 
phenylene or p-phenylene; a diphenylene group; or a 
group consisting of two phenylene groups linked by one 
or more heteroatoms such as oxygen. Polymers wherein 
Ar is a biphenylene ether group have shown the most 
favorable overall properties. 
The monovalent hydrocarbon radicals represented by 
IR can be alkyl grows such as methyl, ethyl, propyl and 
the like; aryl groups such as phenyl, naphthyl, and the 
like; kralkyl groups such as benzyl or phenylethyl; cy- 
cloalkyl groups such as cyclopentyl or cyclohexyl; or 
alkaryl groups such as tolyl, xylyl and the like. More 
than one of these groups can be present in the same 
polymer, for example a methyl and a phenyl group can 
be attached to the silicon atoms adjacent the arylene 
groups. 
The polymers of the present invention can be pre- 
pared in molecular weights from about 10,000 to 
1,000,000, which correspond to values of n from about 
15 to 3,000, depending upon the composition of the 
particular polymer. 
The novel poly(ary1enesiloxane) polymers of this in- 
vention can be prepwed by reacting an arylenedisilanol 
with a cyclic siloxazane compound. The silanol reactant 
is represented by the formula 
A B  
where Z and R have the meanings given above. Illustrative 
examples of silanols which can be used include pphenyl- 
enebis(dimethylsilanol), m - phenylenebis(dimethy1sil- 
and) ,  p-phenylenebis(methylphenylsilanol), m-phenylene- 
bis (methylphenylsilanol) , p - phenylenebis (diphenylsil- 
anol), and bis(p-dimethylhydroxysilylphenyl) ether. 3il- 
anols of this type can be prepared by reaction of arylene- 
bis (dialkoxysilanes) such as pphenylenebis (dimethyl- 
ethoxysilane) with sodium hydroxide according to the 
method disclosed by R. L. Merker and M. J. Scott in J. 
Polymer Sci., A2 (1964) 15 or by other previously known 
methods. 
. .  I . 3." 
. The cyclic siloxazane reactant is selected to provide the 
desired- m d e c u k  structure. For polymers .having three 
siloxane groups in the repeating unit (a value of 3 for x 
in the polymer formula) a siloxazane having the formula 
5 
10 
I 
>. p.: ; 2 . 
where R has the me ghen above and R; i s  a hydro- 
gen atom or an alkyl ,group.quch a$ ,plethyl, ethyl or the 
like, is employed. Compound;s wherein R is methyl are 
preferred since they are more -stable against hydrolysis 
and thus more easily..managed in tha'process. These com- 
pounds react with the silanol at a ratio of one mole -per two 
moles silanol to. give,a .primwy. amine. and the polymer. 
This gromp o€ compounds Js-exemplified by decamethyl-1, 2o 
5-dia~a-3,~~dioxa-~~4,6,8-tetras~a~yclooct~ne. 8 . . 
I For polymem havhg four or five siloxanegoups in the, 
repeating unit (a. value of 4 or 5 for x in the polymer 
formula) a siloxazane having.the formula 
I I. I I .  
25 
Ri R' Ra 
y 0-SI-N-Sll 
L ( S i R , O ) , l  
where m is 1 or 2 ses@ctiveiy, andL-R and R' have the 30 
meaning giveq ahovgi is used., .Compoupds .of ,this type 
react with the silanol at equimolar proportions to give a 
I .. ._I_ _ I  .+  . . 
3,444,127 
, 
(PolFerization of bis(p-dimethyl~~do~~~ylp~eny1) ether and heptmethyl-1-aza-3,S 
diox8-2,4,6-trisilocyclohexane) 
4 
zation is essentially completed in a period of 4 to 8 hours. 
--Polymerization can also be carried ont i n  an organic 
solvent medium. Inert organic solvents such as toluene or 
xylene can be used for this purpose. 
The resulting polymer can be applied as a metal surface 
coating by dissolving it in.a suitable solvent such as toluene 
and spraying the solution onto the surface:Upon curing 
by heating at a temperature such as 150 to 200" C. a clear, 
smsoth elastic CQating i s  .obtained. Hardening or cross- 
nous octoate and t-butyl per- 
such as zinc oxide can be 
combined with the product polymer to provide improved 
coating formulations.. I 
-The pely(ary1enesiloxane) polymers produced as de- 
scribed above exhibit- dermal stability up to about 500 to 
550" C., a? compared with about 450" C. for previously 
known high-tempemtwe silicones and 380" C. for typical 
random poly(ary1eneqilpxane) polymers, 
The invention is further illustrated by the following ex- 
amples. ' I  
Example I 
1 I 
Bis(p - dimefhylhydroxysilylphenyl) ether and hepta- 
methyl- l-aza-3,5-dioxa-2,4,6-trisilacy~ohexane w re react- 
ed for varying times at varying temperatures according to 
the following procedure to produce a poly(ary1enesilox- 
ane) polymey. A mixture of 0.0100 mole diol and 0.0105 
(5% excess) or 0,0110 (10% excess) dazane was heated 
in a 25 by 140 mm. polymerization tube immersed in a 
Wood's metal bath. The resulting polymer was recovered 
in each case, and its inherent viscosity in 0.5% solution in 
to@na at, 309 C. yva~,  determined. The results obtained 
may be seen by reference to the following table. 
, .  . 
TABLE I 
Iqherent Po?jrmer 
Viscosity a Description 
0.40' A tacky gum. 
0.38 Do. 
0.94 A clear gum. 
0.0100 a 0110 i 4 w , i  M.; 1800 7 hrs _ _ _ _ _ _ _  1.73 A rubbery solid. 
0.0100 0.0110 140", 1 M.; looo, 7 hrs _ _ _ _ _ _  1.69 Do. 
0.0100 0: 0106 180'' 8 hrs _ _ _ _ _ _ _ _ _ _ _ _ _ _  _ _ _  0.0lM) 0 Old0 lSqd shrs _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  
b Polymerization was run in a 50 ml. flask with stirring. 
primary amine and the polymer. The cornpounds where m 
azanes were polymer- is 1 and 2 are exemplied by heptamethyf-l-aza-3,5-dioxa- 
low. Further details and results may be seen by reference trioxa-2,4,6,8-tetrasilacy~looctane, respectively. 
The cyc1ic siloxazanes described above can be prepared to the following table. In the table the silanediols are 
by reaction of a,w-dichlorosiloxanes with an amine in a designated as solvent such as petroleum ether. At low temperatures such 
as -30" c. this reaction produces linear bis (methyl- (A) bis(p-dimethylhydroysilphenyl) ether, 
amino) siloxazanes, but at higher temperatures such as 6o (8) nq-phenylenebis(dimethylsilanol), 
50" C. the desired N-methylsiloFozanes are obtained at ( c )  P-phenylenebis(methylphenylsilanol) (isomer mix- 
high yield. At intermediate teqperatures such as 5 to ture), . - 
10" C., a,o-bis(methy1amino) siloxanes are produced, and (l?) p - p h e n y l e n e b i s ( d s i l ~ o l ) ,  
@e, latter :ompounds Wn be (E) bis(P-methYlPhenYlhYdrOXYsilPhenYl) ether, 
zaneq ,by beating in the presence of ammonium sulfate at 65 (F) mrP~n3"lenebis(methylailanol), ' 
150 to 19R9 C, (G,) a-phenylenebis(diphenylsilano1) , and 
heating a stoichiometric mixture.of the silanol and the 
siloxazane. However, a diglit excess, for examples, five 70 (Ij de 
percent of the stiochiometric amount, of the siloxazane is. 
preferably used to comgnsate for the 108s of- this corn- 
ponent by volatilization. A polymerization tFmperature 
from about 140 to 200" C. caq be used, arid best results 
are obtained at a temperature of 160 to 180" C. Polymeri- 75 
2,4,6-trisiiacyciohexane ,and nonamethyl - - - 3,597- 55 ized by the procedure sf Example I, except as noted be- 
, 
ndenqed t"o ~-methyls&t&o- I 
.The palymerhation paction An  carried out by p-qhenylenebis(dimethylsilanol) 
signated as follows: 
3,7-diaxa-2,4,6,8-tetrasila- 
cy clooctane, 
octane, and>,, 
hexane. 
(J)  nonamethyl-l-aza-3,5,7-trioxa-2,4,6,8-tetrasilacyclo- 
(K) ~eptamethyl-l-aza-3,5-dioxa-2,4,6-trisilacyclo- 
3,444,121 
TABLE I1 
(Polymerization of Other Silanediols and Cyclosiloxmanes) 
Polymerization Temperature and Inherent Polymer 
Run No. Diol Cyclosiloxazane Time (" C., Hr.) Viscosity Description 
1 ____.___.____ A (0.00717 mole) - - .- I (0.00359 mole) _ _ _ _ _  160' 8 hrs _ _ _ _ _ _ _ _ _ _ _ _ _  ~ _ _ _  _ _ _ _ _ _ _ _ _ _ _ _  
2..- -. _ _  _ _  A (0.0100 mole) - _ _ _  I (0.00525 mole)- _ _ _ _  161': 8 hrs _ _ _ _ _ _ _ _  _ _  _ _  _ _  _ _  _ _  _ _  _ _  _ _  3.18 Rubbery solid. 
3 _ _ _ _ _ _ _ _ _ _ _ _ _ _  A (0.0100 mole) - _ _ _ _  I (0.0051 mole) _ _ _ _ _ _ _  160°, 8 hrs _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  
4 _ _ _ _ _ _ _ _ _ _ _ _ _ _  A (0.0100 mole) - ___. J (0.0105mole). _ _ _ _ _  160' 8 hrs _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  
5 _ _ _ _ _ _ _ _ _ _ _ _ _ _  B (0.0100 mole) .____ K (0.0105 mole) _ _ _ _ _  160' 8 hrs _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  
6 _ _ _ _ _ _ _ _ _ _ _ _ _ _  c (0.0100 mole) - _ _ _ _  K (0.0105 mole).. _ _ _ _  161°' S hrs _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  
7 _ _ _ _ _ _ _ _ _ _ _ _ _ _  D (0.0100 mole)- _ _ _ _  K (0.0105 mole)- _ _ _ _  160': 8 hrs _ _ _ _ _ _ _ _ _ _  ~ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  ~ _ _ _ _ _ _ _ _ _ _ _ _  Solid. 
8 _ _ _ _ _ _ _ _ _ _ _ _ _ _  E (0.0050 mlle) _ _ _ _ _ _  K (0.00525 mole) _ _ _ _  159", 8 hrs ________________________________________--- 
g ____._________ F (0.0100 mole) _ _  _ _  K (0.0105 mole)- _ _ _ _  160', 8 hrs _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  ~ _ _ _ _ _ _ _ _ _ _  
10 _ _ _ _ _ _ _ _ _ _ _ _  - D (0.0050 mole) _ _ _ _  K (0.00550 mole)- _ _ _  In 10 ml. of refluxing toluene 7 hrs- _ _ _  
11 _ _ _ _ _ _ _ _  ~ _ _ _ _  G (0.0050 mole).. _ _ _ _  K (0.00550 mole)- _ _ _  155" 0.75 hr _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  
12 _ _ _ _ _ _ _ _ _ _ _ _ _  H (0.0100 mole) _ _ _ _ _  E (0.0100 mole) _ _ _ _ _  lid, 8 hrs _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  
13 _ _ _ _ _ _ _ _ _ _ _ _ _  H (0.0050 mole) _ _ _ _ _  I (0.00525 mole) _ _ _ _ _  161°, 8 hrs ._________ _  __. __________ 
14 _ _ _ _ _ _ _ _ _ _ _ _ _  H (0.0100 mole)- _ _ _ _  J (0.0105 mole) _ _ _ _ _ _  161°, 8 hrs. _____._______ _ _ _ _ _ _ _ _ _ _ _ _ _ _  
0.49 A gum. 
2.48 Do. 
3.83 Do. 
1.60 A gum. 
0.15 Liquid. 
Do. 
1.61 Agum. 
0.21 Elsstic solid. 
0.66 Do. 
2.77 A gum. 
1.M Do. 
2.48 Do. 
Chemical analyses were performed on the product 
polymers, and glass transition temperatures were deter- 
mined. The results may be seen by reference to the follow- 
ing table. 
where m is a whole number from 1 to 2, R is 
valent hydrocarbon radical, and R' is an alkyl 1 
a hydrogen atom and those having the formula 
TABLE I11 
(Polymer Properties and Analyses) 
Glass 
Polymer from Transition Analyses Calculated/Found 
Example 11, Temperature Empirical 
Run No. ("C.)  Formula C H Si 
3-- - - - - - - - -. - - - - - -37 CaoH3zOaS4 53.52/53.74 7.19/7.27 25.03/25. OS 
7 (Example I)----. -52 CzzHaOaS1s 50.52/50.62 7.32/7.35 26.86/26.70 
4-- - - - - - - - - - - - - - -65 CzaHiaOeSia 48.27/48.02 7.43/7.34 28.23/28.11 
12 _ _ _ _ _ _  _ _  _ _  _ _  _ _  -_  - -72 ClaHanOaSis 44.60/44.40 7.95/7.93 32.60/30.20 
14 _ _ _ _ _ _  ~ _ _ _ _ _ _  _ _  _ _  -80 ClsH4oOsSia 42.80/42.76 7.98/7.99 33.37/33.19 
5-- - - - - - - - - - - - - -75 CiaHaaOaSfa 44.60/44.49 7.95/7.90 32.60/32.51 
6 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  CzaHasOaSls 56.26/56.00 6.90/6.97 25.31/25.02 
9 _ - _ _ - _ _  ~ - --------- -42 CZSH~SO~S!~ 56.26/56.23 6.90/6.83 25.31/25.08 
10 _ _ _ _ _ _ _ _ _  ~ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _  CssHaaOBls 63.66/63.75 6.W6.25 20.68/20.45 
a mono- 
:adical or 
R' 
I 
N 
RISi' 'SiR, 
Thermogravimetric analyses were performed on se- 
The samples were heated to 900" C. at a rate of 15" C. 35 
per minute in a nitrogen atmosphere, and their losses in 
weight were recorded. All samples except one showed a 
weight loss less than 10 percent at 500" C., and all showed 
weight losses of about 50 to 80 percent at 600" C. 
which is limited only as indicated by the appended claims. 
What is claimed is: 
1. The process for preparing a polymer having the 
lected polymer samples to determine their beat stability. 
b b  
'N' 
I I  
RaSi SiRa 
I 
R' 
where R is a monovalent hydrocarbon radical and R' is 
an alkyl radical or a hydrogen atom. 
2. The process according to claim 1 wherein a mixture 
45 of said silanol and siloxazane is heated at a temperature 
of 140 to 2 0 "  C. for 4 to 8 hours. 
3. The process according to claim 2 wherein said mix- 
ture is heated at a temperature of 160 to 180" C. 
4. The process of claim 2 where a slight stoichiometric 
50 excess of said siloxazane is provided in said mixture. 
4o The above examples are merely illustrative and are not 
to be understood as limiting the scope of the invention, 
formula 
-~i-z-D--o]$ r R  
Lk 
where Z is an arylene group, R is a monovalent hydro- 
carbon radical, n is from 15 to 3,000 and x is 3 to 5 which 
comprises reacting at a temperature of 140 to 200" C. a 
silanol having the formula 
References Cited 
UNITED STATES PATENTS 
55 2,561,429 7/1951 Sveda _ _ _ _ _ _ _ _ _ _ _ _  260-448.2 
R R  2,562,000 711851 Sveda _ _ _ _ _ _ _ _ _ _ _ _ _  260-46.5 
HO--$i-z--$i-OH 3,202,634 8/1965 Merker _ _ _ _ _ _ _ _ _ _ _ _  260-46.5 
I t  3,287,310 1111966 Omietanski _ _ _ _ _ _ _ _ _ _ _  260-37 
3,318,835 5/1867 Spork _ _ _ _ _ _ _ _ _ _ _ _ _  260-448.2 
60 3,350,350 10/1967 Nitzsche et al. _ _ _ _ _ _ _  260-46.5 
R R  
where Z is an arylene group and R is a monovalent 
hydrocapbon radical with a siloxozane in the group con- 
sisting of those having the formula 
HOSEA E. T A Y J ~ R ,  primary ~~~~i~~~~ 
M. I. MARQUIS, Assistant Examiner. - .  
US. C1. X.R. 65 
117-161; 26012, 448.2 


Preparation of ordered poly /arylenesiloxane/ polymers

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