Note: Descriptions are shown in the official language in which they were submitted.
TITT.~
NOVEL FLUORODIOXOLES AND FLUORODIOXOLE POLYMERS
BACKGROUND OF T~E I~VENTION
This invention relates to certain novel
fluorodioxoles, their polymers, and processes for
making the fluorodioxoles.
Various dioxolanes having the following
formula 1 are known from ~erman Patent 2,604,350 to
Stanford Research Institute:
CHX - CHY
O ~ c~ ~ 1 )
F F
where each of X and Y may be F or C1.
Dioxolanes corresponding to formula (2),
- 15 below, are reported in U.S~ Patent 3,749,791 to
Terrell et al.:
CHX - CHX'
~ C~ (2)
3 3
- where X is Cl or F, and X' is H, Cl, or F.
The intermediate 2,2-bis(trifluoromethyl)-
1,3-dioxolane is known from U.S. Patent 2,925,424 to
Simmons.
Dechlorination of
2,2-bis(trifluoromethyl)-4,5-dichloro-4,5-difluoro-1,3-
dioxolane to the corresponding perfluorodioxole has
been reported by Resnick ln U~S. Patents 3,865,845
and 3,978,030.
; That perfluorodioxole has been found to form
- 30 both homopolymers and copolymers (especially with
tetrafluoroethylene) which have interesting chemical
and physical properties (e.g., chemical inertness to
hydrogen fluoride, optical clarity, ability to form
films). It ean be speculated that simpler and/or
cheaper fluorodioxoles al50 would be capable of
forming useful homopolymsrs and copolvmers.
SI~M~ARY OF THE ~'~VENTIO~
According to the present invention, there is
provided a class of fluorodioxoles having the
following formula (3):
CY C%
` C~ (3)
R R
in which Y is hydrogen or chlorine; Z is hydrogen,
fluorine, or chlorine; and R is fluorine or the
trifluoromethyl group; with the proviso that when R
is trifluoromethyl, only one of Y and Z can be
hydrogen or chlorineO
These fluorodioxoles are useful monomers for
the preparation of homopolymers and copolymers having
a wide range of potential applications. This
, invention also includes such polymers as well as
certain novel polymers of known dioxoles. Generally,
the monomers from which the novel polymers of the
~resent invention are made can be represented by the
same formula (3) in which Y, Z and R have the same
meaning as above, but the above proviso no longer
- applies.
DETAIL~D DESCRIPTIO~ OF THE I~VE~TIO~i
The fl~loro~ioxoles of the present invention
can be conveniently made by dechlorination o~ the
corresponding 4,5-dichlorodioxolanes with magnesium
in the ~resence of a catalytic amount of iodine and
of a water-soluble mercury salt or metallic mercury,
as shown in the following equation.
CCl~ - CClz
C ~ ~9, I2 (3) ~ MgCl2 ,
R R Hg or Ha
(4)
Where R, Y, and Z have the same meaning as
~! 35 in Formula (3), above.
i
Ltj
This dechlorination reaction preferably is
carried out in solution in tetrahydrofuran. For
maximum production rate, an excess of magnesium is
employed in this reaction, the preferred amount heing
1.1 to 8 gram-atoms of magnesium per t~70 gram-atoms
of vicinal chlorine to be removed. Ho~ever, for
maximum yield of dioxole, less than stoichiometric
- amounts may be desirable to minimize side reactions.
Mercury salts suita~le in this reaction include, for
example, mercuric-chloride, acetate, and nitrate.
~etallic mercury, when used, forms in situ an amalgam
with magnesium. However, an amalgam can be prepared
separately in advance. The amount of mercury need
not be large. For example, a weight of mercuric
- 15 chloride about equal to the weight of iodine, in turn
equal to about 1~ of the weight of magnesium usually
is sufficient. A slightly larger amount o metallic
mercury may be advisable to permit more effective
agitation and thus easier amalgam formation.
Although some 4,5-dioxolanes represented hy
. the above formula (4) are known, as discussed
earlier, those represented by formula (5), below are
believed to be novel:
CYCl-CFCl
`C~
R R (5)
in which R is fluorine or trifluoromethyl, and Y is
hydrogen or chlorine.
All the fluorodioxoles of this invention
copolymerize with tetrafluoroethylene (TFE) to tough,
crystalline copolymers suitable for use as a
dielectric in electrical and electronic equipment.
In these crystalline copolymers the fluorodioxole
usually is present in an amount of ahout 12 ~ole
3S percent oe less. r~hen the fluoroaio~ole content
~P~396~5
increases beyond 12 mole percent, the copolymers
become amorphous. ~at~rally, the 12 mole percent
level is not a sharp line of demarcation, since
copolymers having some crystallinity may exist above
it, and significantl~ amorphous copolymer ~ay exist
below it. However/ one can expect that a large
majority of copolymers having less than 12 mole % of
a fluorodioxole (3) will be crystalline, an~ a large
majority of those containing more than 12 mole % of
such a fluorodioxole will be amorphous. The
- amorphous copolymers are tough and at moderate
molecul~r weight soluble in various organic liquids,
such as 1,1,2-trichloro-1,2,2-trifluoroethane and
Fluorinert* Electronic Liquid FC-75 (3~ Company) and
are particularly suitable for finishes and coatings
- that are chemically inert and are stain and weather
- resistant. Fluorodioxoles (3) in which each of Y and
Z is chlorine could not be incorporated into a
copolymer with TFE at a high enough level to result
~ 20 in an amorphous copolymer. Those copolymers that
were made were crystalline.
- Fluorodioxoles (3) form with vinylidene
fluoride (~2) and TFE strong, plastic and
elastomeric terpolymers suitable for
~: 25 corrosion-resistant seals, gaskets, and linings.
_ Finally, the fluorodioxoles corresponding to
~~ formula (3) in which Y is hydrogen and Z is hydrogen
or fluorine ~orm homopolymersl which are tough~
amorphous resins suitable for transparent glazing
~ 30 materials, especially as sight glasses in chemically
corrosive uses employing hydrogen fluoride.
In addition to the novel dioxoles of Formula
3 as defined ~herein, ~ioxoles in which both X and Y
`- are hydrogen or chlorine~ and R is trifluoromethyl
can be made by the same general techniques but are
*denotes trade mark
.
~ 4
,
_,
;.
not believed to be novel. Those dioxoles also form
novel and valuable copolymers; the dioxoles in which
X is hydrogen, and Y is hydrogen or fluorine also
form homopolymers.
3roadlyr this invention includes, thereforer
homopolymers of the novel dioxoles of this invention
as well as copolymers of the dioxoles represented by
formula (3) in which Y is hydrogen or chlorine; Z is
hydrogenr fluoriner or chlorine; and R is fluorine or
trifluoromethyl with tetrafluoroethylene and
terpolymers with tetrafluoroethylene and vinylidene
fluoride.
This invention is now illustrated by
representative examples of certain preferred
embodiments thereof, wherein all parts, proportions~
! and percentages are by weight unless otherwise
indicated. Further, unless shown otherwise, all
reactions, separations, distillations, and storage
were carried out in a nitrogen atmosphere.
~ABLE I
SUM~ARY OF PREPARATION OF DIOXOLES OF
FORMULA l3) AND DIOXOLAN~S OF FOR.~ULA (4)
Example Compo~nd Com~ound Substituents
~o. No. Y Z R
PreP. of:
lA (4a) Cl F CF3
lB (3a) Cl F CF3
.lB (3b) F H CF3
lB (4b) F H CF3
lC (3a) Cl F CF3
lD (3b) F H CF3
8A (4c) ~ H CF3
8A ~d) Cl H CF3
8A (4e) Cl Cl CF3
8B (3c) H H CF3
8B (3d) Cl R CF3
8B (3e) Cl Cl CF3
8C (3d) Cl H CF3
t 15 . 15A ~4f) Cl F . F
15B (3f) Cl F F
15B ~3g) F H F
15B (4g) F H F
16A/B (4g) F H F
17 (39) F H F
22 (4h) H H F
22 (3h) H H F
(4i) Cl H F
(3i) Cl H F
28 (3i) Cl Cl F
28 ~4j) Cl Cl F
2S
/
~ 35
- TABLE II
SUMMARY OF EXA~PLES --POLYMERIZATION
Example Monomer Polymer Properties
~o. Com~ound No. Comonomer ~ol ~ ~ioxole, Tm,* Tg**
2 (3~) - 100%, Tg~300C
3 (3b) TFE 5.2~, Tm=266 & 320C
4 (3b) TFE 28.8~, Tg-58C
(3b) TFE 2.4~, Tm=307C
6 (3a) TFE 3.1%, Tm=295C
- 7 (3a) TFE/VF2 5.3~,14.3~ TFE; Tm-131C
9 (3c) TFE 6.9%, Tm=253C
(3c) TFE 46.3%, Tg=61C
11 (3c) TFE/VF2 7.9%, 36.4% TFE; Elast.,
Tm=114C
12 (3c) - 100%
15 13 (3d) TFE 5.9%, Tm=269C
14 (3c)/(3d) TFE 8.6~ (3c)/6.2~ (3d),
Tg=54C
~- 18 (3~) TFE 4.0%, Tm=274C
19 (3g) - 100%
20 20 (3f) TFE 10.5~, Tg=61C
21 ~3f) TFE~VF2 g.9~, 27.7% TFE; no Tm
23 (3h~ - 100
24 (3h) TFE 7
26 (3i) TFE 6%
25 27 (3e) TF~ 0.6~, Tm=312C
29 (3j) TFE 1.4~, Tm=310, 297C
;` * melt temperature (indicates that the polymer has
crystallite regions)
** glass transition temperature (indicates that the
polymer is amorphous)
ExamPle 1
Preparation of 2,2 bis(trifluoromethyl)-
4-chloro-5-fluoro-1,3-dioxole, (3a),
2,~-bis(trifluoromethyl)-4-1uoro-1,3~dioxole, (3b),
and the corresponding dioxolanes (4a) and ~4b).
9Çi~5
A. 2,2-Bis(trifluoromethyl)-4,4,5-trichloro-
5-fluoro-1,3-dioxolane, (4a).
A 330 mL Hastelloy* C lined shaker tube was
ch~rged under anhydrous conditions with 100 g (0.285
mole) of 2,2-bis(trifluoromethyl)-4,4,5,5-tetrachloro-
1,3-dioxolane (4e) and 8.6 g (0.0432 mole) of
antimony pentachloride; the tube ~las then chilled to
about -50C, and 20 g (1 mole) of hydrogen fluoride
was introduced into it. The tube was mounted in a
horizontal shaker, agitated for 5 hours at 70C, then
chilled in wet ice, slowly vented, and opened. The
tube contents were dumped into wet ice. The liquid
product was separated from the ice water, washed
twice with 50 mL portions of cold water, then with 20
mL of a 10% aqueous sodium carbonate solution. There
was obtained 83.5 g of a clear, colorless liquid
product of which approximately 93% was the desired
2,2 bis(trifluoromethyl)-4,4,5-trichloro-5-fluoro-1,3-
dioxolane, (4a).
The product was distilled at atmospheric
pressure on a 0.76 m spinning band column; a small
amount of 2,2-bis(trifluoromethyl)-4,5-dichloro-4,5-
difluoro-1,3-dioxolane (about 2% of the product)
boiling at 85-86C distilled first, followed by the
2,2-bis(trifluoromethyl)-4,4J5-trichloro-5-fluoro-1,3-
dioxolane, b.p. 115C, which was obtained as a
colorless, clear liquid in purity exceeding 9~%.
Both infrared spectroscopy and Fluorine-19 nuclear
magnetic resonance spectroscopy were consistent with
this chemical structure.
The pot residue was largely starting
material, approximately 5~ of the total mixture from
the shaker tube run.
B. Dechlorination of 2,2-bis(tri1uoro-
methyl)-4,4,5-trichloro-5-fluoro-
1,3-dioxolane, (4a).
*denotes trade mark
3~
A 300 mL, 3-neck glass flask equipped with
magnetic stirrer, thermometer, Vigreux column, still
head to a 100 mL receiver, and dry ice trap under 100
kPa of nitro~en was charged with 165 mL of
l-propanol, 42.6 g (0.651 mole~ of zinc dust, and 1.
9 (0.0109 mole) of zinc chloride. The mixture was
stirred while being heated to 98C over a 21 minute
period; when this temperature was reached,
2,2-bis(trifluoromethyl)-4,4,5-trichloro-5-fluoro-1,3-
dioxolane, 72.0 g (0.217 mole~, was introduced intothe refluxing mixture via a svringe pump at
0.33 mL/minute. Thirty-five minutes later the head
temperature fell to 59C, and distillation of the
product was started. Total addition time was 127
minutes. Total ~istillation time was 268 minutes,
during which time the head temperature decreased to a
minimum of 55C. The distillate, 60 mL, contained
some l-propanol which was extracted with water,
leaving 47.7 g of a clear, colorless liquid
containing about 52% of 2,2-bis(trifluoro-
methvl)-4-chloro-S-fluoro-1,3-dioxole, (3a), 25~ of
2,2-bis(trifluoromethyl)-4-fluoro-1,3-dioxole, (3b),
and 22~ of 2,2,-bis(trifluoromethyl)-4,5-
dichloro-4-fluoro-1,3-dioxolane (4b) 3S a mixture of
30% cis and 70~ trans isomers.
The crude reaction product was fractionated
at atmospheric pressure on a 0.51 m spinning band
column. 2,2-Bis(trifluoromethyl)-4-fluoro-1,3-
dioxole, (3b), b.p. 44-45C, polymerizes
spontaneously at room temperature when pure. It was
therefore collected in a receiver maintained at -80C
and stored in a dry ice chest. 2,2-Bis(trifluoro-
methyl)-4-chloro-5-~luoro-1,3-dioxole, (3a),
distilled at 56C; this monomer did not polymerize
spontaneously ~t room temperature~ The cls/trans
mixture of 2,2-bis(tri-fluoromethyl)-4,5-dichloro-
4-fluoro-1,3-dioxolane, (4b), distilled within the
range of 82-90C.
The IR, F-l9 and proton N~IR spectra, and
mass spectrometry support the above chemical
structures.
C. Alternate dechlorination of
2,2-bis(trifluoromethyl)-4,4,5-trichloro-5-fluoro~
dioxolane, (9a).
The equipment described in the above section
B was charged with 80 mL of tetrahydrofuran, 10.8 g
(0.444 mole) of magnesium turnings, 0.2 g of mercuric
chloride, and 0.2 g of iodine and heated to 66C
(iodine color disappears). 2,2-Bis(trifluoro-
methyl)-4,4,5-trichloro-5-fluoro-1,3-dioxolane,
33.1 g (0.1 mole), was added by means of a syringe
pump at the rate of 0.16 mL/minute over a period of
110 minutes. Distillation was started 41 minutes
after the addition; the head temperature remained at
54~55C during the remainder of the addition. The
distillation was stopped after 2.5 hours, and the
distillate was extracted with water to remove some
tetrahydrofuran. The extracted clear, colorless
liquid was found by ~as chromatography to contain
about 95~ of 2,2-bi~s(trifluoromethyl)-4-
chloro-S-fluoro-1,3-dioxole, (3a); the
2,2-bis(trifluoromethyl)-4-fluoro-1,3-dioxole, (3b),
amounted to only 1~.
D. Alternate preparation of 2,2-bis(tri-
fluoromethyl)-4-fluoro-1,3-dioxole, (3b)o
Using the same equipment, except for a
smaller, 100 mL flask, a mixture of 30 mL of
tetrahydrofuran, 3.6 g of magnesium turnings, 0.2 g
of mercuric chloride, and Ool y of iodine was heated
to reflux. 2,2-Bisttrifluoromethyl)-4,5-dichloro-4-
11
fluoro-1,3-dioxolane, (4b3, 10 g, (prepared as
described in Section B, above) was then introduced
into the flask at approximately 0.19 mL/minute over a
34 minute period. Distillation was started 21
minutes after the a~dition was completed and
continued until 20 mL of cold distillate was
recovered. This was extra~ted with ice water to
remove tetrahydrofuran. The remaining product was
2,2-bis(trifluoromethyl)-4-fluoro-1,3-dioxole, (3b).
Example 2
Homopolymerization of 2,2-bis(tri-
fluoromethyl)-4-fluoro-1,3-dioxole, (3b).
T~is monomer, 4.6 g, (99.88~ pure by gas
chromatography) was placed at 25C in a small,
tightly ca~ped vial under room lighting conditions.
;~ Within a few hours the viscosity of the clear liquid
increased to that of a light syrup, and overnight a
solid, clear, colorless plug of polymer formed on the
bottom of the vial.
A small sample of the monomer-polymer syrup
was evaporated on a salt plate to remove the residual
monomer and form a film of the homopolymer. The
infrared absorbance spectrum of this film was
consistent ~ith the molecular structure of a
homopolymer of 2,2-bis(trifluoromethyl)-4~fluoro-
1,3-dioxole, (3b).
The plug was placed in a vacuum oven at
110-120C to remove residual monomer, and then a
sample was examined by Differential Scanning
Calorimetry between room temperature and 300Co
There were no second order transitions or melting
points in this re~ion, indicating that the
homopolymer was amorphous and that its Tg was above
- 300C.
3~
12
Example 3
Crystalline copoly~er of 2,2-bis(trifluoro-
methyl)-4-fluoro-1,3-dioxolc, (3b), and TFE.
A 110 mL stainless steel shaker tube ~as
charged with a cold solution containing 100 g of
1,1,2-trichloro-1,2,2-trifluoroethane, 1.0 g of the
dioxole, and 0.03 ~ of bis~4-t-butylcyclohexYl)
peroxydicarbonate; the tube was chilled to -50C and
alternately evac~ated and flushed with nitro~en three
times. The evacuated tube was then charged with lO g
of tetrafluoroethylene and agitated in a horizontal
shaker. The tem~erature was held at 55C for two
hours and then at 65C for two hours. After cooling
the tube and venting, the resulting suspension of
; 15 copolymer in 1,1,2-trichloro-1,2,2-trifluoroethane
; was recovered. The solvent was distilled off, and
the polymer was dried to give ~.7 g of white, solid
granules. A portion of these was pressed at 300C
into a tough, self-supporting filmO The infrared
spectrum of the film showed absorbancies
characteristic of a tetrafluoroethylene/2,2-bis(tri-
fluorome~hyl)-4-fluoro-1,3-dioxole copolymer.
Differential Scanning Calorimetry showed a major,
broad, crystalline melting point at 266C; there also
25 was a minor melting point at 320C. Infrared and
F-l9 NMR s~ectra support the copolymer struGture
containing 94.8 mole ~ of tetrafluoroe~hylene and 5.2
mole % OL 2,2-bis(trifluoromethyl)-4-fluoro-
1,3-dioxole, (3b).
Example 4
- Amorphous copolymer of 2,2-bis(trifl~oro-
methyl)-4 fluoro~1,3-dioxole, (3b), and TFE.
A snaker tube was charged with 100 g of
1,1,2-trichloro-1,2,2-trifluoroethane, 0.03 g of
bis(4-t-hutylcyclohexyl) peroxydicarbonate~ 5.0 g
12
(0.022 mole) of the dioxole, and 5.0 g (0.05 mole) of
TFE. Polymerization was carried out at 55 and
65C. ~fter sep~rating and drying the product, 4.5 a
of a white solid polymeric product was obtained. A
portion oE the product was pressed at 230C into
thin, tough, clear, colorless, self-supporting
films. ~he infrared and F-l9 N~IR spectra established
the product to be a copolymer containing 71.2 mole %
of TFE and 28.8 mole ~ of the dioxole. Differential
Scanning Calorimetry showed a Tg at 58C but no
melting ~oint, thereby indicating that the copolymer
was amorphous.
Example 5
A high melting crystalline copolymer of
,3 15 2,2-bisttrifluoromethyl)-4-fluoro-1,3-dioxole, (3b)
;- and TFE.
A shaker tube was charged with 100 9 of
1,1,2-trichloro-1,2,2-trifluoroethane, 0.03 g of
bis(4-t-butylcyclohexyl) peroxydicarbonate, 0.5 g
t0.0022 mole) of the dioxole, and 10 g (0.1 mole) of
TFE. Polymerization was carried out at 55 and
65C. After se~arating and drying the product, 9.4 g
of a white, solid polymer was obtained. A portion of
the polymer was pressed at 330C into thin, tough,
colorless, transparent, self-supporting films. The
infrared and F-l9 NMR spectra were consistent with a
copolymer of 97.6 mole ~ TFE and 2.4 mole ~ of
2,2-bis(trifluoromethyl)-4-fluoro-1,3-dioxole.
Differential Scanning Calorimetry showed a relatively
sharp melting point at 307C, thus indicating the
crystalline nature of the polymer.
ExamPle 6
A crystalline copolymer of 2,2-bis-
(trifluoromethyl)-4-chloro-5-fluoro-1,3-dioxole,
(3a), and TFE.
13
14
A shaker tube was charged with 100 g of
1,1,2-trichloro-1,2,2-trifluoroethane, 0.03 g of
bis(4-t~butylcyclohexyl) peroxydicarbonate, 1.5 g
(0.0058 mole) of the dioxole and 10 g of 1'FE, and
polymerization was carried out at 55 and 65C.
After se~arating and drying the ~roduct, 4.3 g of a
white, solid polymer was obtained. A portion of the
polymer was pressed at 300C to give tough, thin,
colorless, clear, self-supporting films. Infrare~
and F-19 NMR spectra support the structure of a
copolymer containing 96.9 mole % of TFE and 3.1
mole % of 2,2-bis(trifluoromethyl)-4-chloro-5-
fluoro-1,3-dioxole, (3a). Differential Scannin~
Calorimetry showed a melting point at 295C,
indicating the crystalline nature of the polymer.
Example 7
.
A terpolymer of 2,2-bis(trifluoromethyl)-4-
chloro-S fluoro-1,3-dioxole, (3a), vinylidene
fluoride, and TFE.
A shaker tube was charged with lOQ ~ of
1,1,2-trichloro-1,2,2-trifluoroethane, 3.0 g of the
dioxole, 0.03 g of bis(4-t-butylcyclohexyl~
peroxydicarbonate, 6.0 g of vinylidene fluoride, and
6.Q g of TFE. Polymerization was carried out at 55
and 65C for 4 hours under autogenous pressure.
After separating and drying the product, 3.6 g of a
white, solid polymer was obtained. A portion of this
polymer was pressed at 230C into thin, tough, clear,
self-supporting films. Infrared and F-19 NMR spectra
identified the polymer as a terpolymer containing
14~3 mole % of TFE, 80.4 mole % of vinylidene
fluoride, and 5.3 mole ~ of the dioxole.
Differential Scanning Calorimetry showed a ~elting
point at 131C, thus demonstrating the crystalline
character of the polymer
14
Example 8
Preparation of 2,~-bis(trifluoromethyl)-
1,3-dioxole, (3c), 2,2-bis(trifluoromethyl)-4-
chloro-1,3-dioxole, (3d), and 2,2-bis(trifluoro-
5 methyl)-4,5-dichloro-1,3-dioxole, (3e).
A. Synthesis of 2,2-bis(trifl~oromethyl)-
4,5-dichloro-1,3-dioxolane, (4c), 2,2-bis(tri
fluoromethyl)-4,4,5-trichloro-1,3-dioxolane, (4d),
and ~,2-bis(trifluoromethyl)-4,4,5,5~tetrachloro-
1,3-dioxolane, (4e).
A 300 mL, 3-neck round bottom ~lask equipped
with a magnetic stirrer, chlorine gas inlet,
thermometer, and a water condenser topped by a dry
ice condenser communicating with a drying tower and
then with a water scrubber was charged with 210 9
(1.0 mole) of 2,2-bis(trifluoromethyl)-1,3-dioxolane.
After purging the system with nitrogen, chlorine was
I passed into the solution at such a rate as to
; maintain a yellow coloration of the solution. The
stirred mixture was irradiated with a 275 watt
General Electric sun lamp so as to maintain a
reaction temperature for the most part in the range
~- of 46-72C for 4.5 hours. The concentration of the
starting dioxolane in the reaction mixture had
dropped by then to approximately 0.1~, and the
reaction was terminated. Residual chlorine and
hydrogen chloride were removed with a water
aspirator, leaving a colorless, clear liquid weighing
28~ g and containing the di-, tri-, and tetrachloro-
derivatives (4c), (4d~, and (4e), as confirmed byN~, mass spectrometry, and gas chromatographic
analyses.
B. Dechlorination of the di-, ~ri-, and
tetrachlorodioxolanes obtained in step A, above.
~5
s~
A 500 mL, 3-neck, round bottom flask
equipped with a magnetic stirrer, a syringe pump
inlet, a ther~ometer, a 15-cm still leading to a 100
mL recei~er and then to a nitrogen tee and a bubbler
was charged with 98.1 ~ ~1.5 moles) of zinc dust,
3.0 g (0.022 mole) of ~inc chloride, and 300 mL of
_-butyl alcohol. A syringe pump was charged ~ith
139.5 g of the chlorinated dioxolanes from step A.
After the flask contents were brought to 115C, the
chlorinated dioxolanes were pumped into the flask at
0.33 mL/minute. The addition was completed in 224
minutes. Twenty minutes after the start of the
addition, distillation began at a rate of about 15-20
mL/hour. The head temperature then was 79-80C but
during the distillation decreased to 75C and at the
end was 116C; 119.8 g of product containing hutyl
alcohol was distilled. The produc~ distribution was
about 21% of 2,2-bis(trifluoromethyl)-1,3-dioxole,
(3c), 47~ of 2,2-bis(trifluoromethyl)-4-chloro-
1,3-dioxolel (3d), and 30~ of
2,2-his(trifluoromethyl)-4,5-dichloro-1,3-
dioxole, (3e). The crude product was fractionated at
- atmospheric pressure on a 0O76 m spinning band column
to provide each dioxole as a clear, colorless liquid
having a ~urity of at least 99%:
2,2-bis(trifluoromethyl)-1,3-dioxole, (3c), b.p~
67C; 2,2-bis(trifluoromethyl)4-chloro-1,3-dioxole,
~3d), b.p. 76C; and 2,2-bis(trifluoromethyl)-
4,5 dichloro-1,3-dioxole (3e), b.p. 85C. The
infrared, F-l9 and proton N.~R, and masq spectrometry
data ~or these dioxoles support their molecular
structures.
C. Alternate synthesis of 2,2-bis(trifluoro-
methyl)-4-chloro-1~3-dioxole~ (3d).
16
~3~
17
A 100 mL, 2-neck, round-bottom glass flask
equipped with magnetic stirrer, thermometer, Vigreux
- column, still head, and receiver was charged under a
nitrogen blanket with 40 mL of di(ethylene glycol)
dimethyl et`ner, 9.8 g of crude
2,2-bis(trifluoromethyl)-4,5-dichloro-1,3-dioxolane,
(4c), and 6.7 g of solid potassium hydroxide. The
flask contents were heated at 1~1C for 2 hours
during which time the 2,2-bis(trifluoro-
methyl)-4-chloro-1,3-dioxole, (3d), distilled overO
Purified by gas chromatography, the product had the
same retention time and infrared spectrum as an
authentic sample of 2,2-bis(trifluoromethyl)-
; 4-chloro-1,3-dioxole, (3d).
Exam~le 9
i A crystalline copolymer of 2,2-bis(tri-
fluoromethyl)-1,3-dioxole, (3c) and TFE.
A shaker tube was charged with 100 g of
1,1,2-trichloro-1,2,2-trifluoroethane, 0.03 g of
bis(4-t-butylcyclohexyl) peroxydicarbonate, 1.5 g
~ (0.0072 mole) of the dioxole, and 10 9 (0.1 mole) of
TFE. Polymerization was carried out at 55 and
65C. After separating and drying the product, 10.5
`~` g of a white, solid polymer was obtained. A portion
25 of the polymer was pressed at 300C into tough,
clear, colorless, self-supporting films. Infrared
and F-19 N~R spectra established a copolymer
structure of 93.1 mole ~ of TFE and 6.9 mole % of
2,2-bis(trifluoromethyl)-1,3-dioxole, (3c).
30 Differential Scanning Calorimetry showed a melting
point at 253C, thereby establishing the crystalline
character of this polymer.
Exam~le 10
A An amorphous copolymer of 2,2-bi~(tri-
35 fluoromethyl)-1,3-dioxole, (3c) and TFEo
18
A shaker tube was charge~ with 100 g of
1,1,2-trichloro-1,2,2-trifluoroethane, 4.2 g (0.02
mole) of the dioxole, 0.03 g of bis(4-t-butyl-
cyclohexyl) peroxydicarbonate, ar.d 10 g of TFE.
Polymerization was carried out at 55 and 65C under
autogeno~s pressure or 4 hours. ~fter separation
and drying, a white, solid polymer, 1.4 g, ~as
obtained. It was soluble in the trichlorotrifluoro-
ethane solvent; a clear, transparent, ~elf-supporting
film was cast from this solution. Infrared and F-l9
and proton NMR spectra identified the copolymer as
containing 46.3 mole % of the dioxole and 53.7 mole %
of TFE Differential Scanning C~lorimetry showed a
Tq at 61C and other transitions at 113C and 246C;
there was no melting point, and the polymer was
therefore amorphous.
Exa~ole 11
An elastomeric terpolymer of 2,2-bis~tri-
fluoromethyl)-1,3-dioxole, (3c), vinylidene fluoride,
20 a~d TFE.
A shaker tube was charged with 100 g of
1,1,2-trichloro-1-~,2,-trifluoroethane, 3.0 g (0.0144
mole) of the dioxole, O.G3 g of bis(4-t-butyl-
cvclonexvl) peroxydicarbonate, 6.0 g (0.094 mole) of
25 vinylidene fluoride, and 6.0 q (0.06 mole) of TFE.
Polymerization was carried out under a-1togenous
pressure at 55 and 65C. After separation and
drying, a white, solid poly~er, ~.4 q, was obtained.
It was not soluble in the trichlorotrifluoroethane.
30 A portion of the ~olymer was pressed at 230~C to give
thin, tough, elastomeric, clear, self-supporting
films. Infrared and F-19 NMR spectra identified the
i terpolymer as contain ng 36.4 mole % of TFE~ 55.7
mole ~ of vinylidene fl~oride, and 7~9 mole % of
35 dioxole. ~iferential Scanning Calorimetry showed a
18
s
19
melting point at 114C, indicating the crystalline
nature of the polymer~
Exam?le l2
Homopolymer of 2,2-bis(trifluoromethyl)-
1,3 dioxolQ, (3c)-
The dioxole, 3.0 g, which had been kept in adry ice chest, was placed in a 10 mL closely capped,
clear, glass vial and allowed to stand at room
temoerature under laboratory fluorescent lighting
conditions. After two weeks, ~ portion of the liquid
was pl~ced on a salt plate and allowed to ev~porate,
leaving a thin, transparent, clear, colorless solid
film~ In~r~red analysis of this film was consistent
with the homopolymer structure.
Exam~le 13
crystalline copolymer of TFE and 2,2-bis-
(trifluoromethyl)-4-chloro-1,3-dioxole, (3d).
A shaker tube was charqed with 100 g of
1,1,2-trichloro,1,2,2-trifluoroethane, 0.03 g of bis
(4-t-butylcyclohexyl) peroxydicarbonate, 1.5 g
(0.00613 mole) of the dioxole, and 10 g (0.1 mole) of
TFE. Polymerization was carried out under autogenous
pressure at 55 and 65Co After separation and
drying, a white solid polymer, 5.0 g, was obtained.
A portion of the polymer was pressed at 300C into
thir, tough, clear, self-supporting films. Infrared
and F-l9 N~IR s~ectra showed the copolymer to contain
94.1 mole ~ of TFE and 5.9 mole % of the dioxole.
Differential Scanning Calorimetry showed a melting
3~ ~oint at 269~C, thus indicating the polymer to be
crystalline.
! Example 14
An amorphous terpolymer of TEE with ~,2-bis-
(trifluoromethyl)-1,3-dioxole, (3c) and
~,2 bis(trifluoromethyl~-4-chloro-1,3-dioxole, ~3d)o
19
2~
A shaker tube was charged with 100 g of
1,1~2-trichloro-1/2,2-trifluoroethane, 1.0 g of
2,2-~is(trifluoromethyl)-1,3-dioxole, (3c), 2.0 g of
2,2-bis(trifluoromethyl)-4-chloro-1,3-dioxole, ~3d)
0.03 g of bis(4-t-butylcyclohexyl) peroxydicar~onate,
and 10 g TFE. Polymerization was carried out under
autogenous pressure at 55 and 65C. After
separation and drying, 3 g of white, solid, ~olymer
granules were obtained. A portion of tne ~olymer was
pressed at 300C to give thin, tough,
self-supporting, colorless, clear films. The
infrared and F-l9 NMR spectra were consistent with a
terpolymer structure consisting of 85.2 mole ~ of
TFE, 8 . 6% of 2,2-bis(trifluoromethyl)-1,3-dioxole,
(3c), and 6.2 mole % of 2,2-bis(trifluoromethyl)-4-
chloro-1,3-dioxole~ (3d). The Differential Scanning
Calorimetry analysis showed a Tg at 54C but no
melting point, thereby indicating the polymer to be
amorphous.
~xample 15
Preparation of 2,2,4-trifluoro-5-chloro-
1,3-dioxoler (3f) 2,2,4-trifluoro-1,3-dioxole, (3g),
and the corresponding dioxolanes (4f) and (4g).
A. 2,2,4-trifluoro-4,5f5-trichloro-1,3-dioxolane
(4f)
A dry, 360 mL "Hastelloy~ C lined shaker
tube was charged with 81.8 g (0.33 mole) of
2,2-difluoro-4,4,5,5-tetrachloro-1,3-dioxolane, ~4j),
containing 9.0 g (0.03 ~ole) of antimony
pentachloride. The tube was cooled, alternately
evacuated and purged with nitrogen three times, and
charged with 22 g (1~1 mole) of hydrogen fluoride~
The ~ube was agitated and warmed to 40C over a
period of 1 hour, heated under autogenous pressure
for 4 hours at 40C, then cooled to 0C, 510wly
2~
s
vented, and opened. The contents were poured into
ice; the organic phase was se~arated from the aqueous
phase, extracted twice with distilled water and once
with an aqueous 10~ sodium carbonate solution; 63.3 g
of crurle product was obtained which contained about
3 . 9% of 2, 2, 4, 5-tetrafluoro-4,5-dichloro-1,3-
dioxolan~, 85.8% 2,2,4~trifluoro-4,5,5-tri-
chloro-1,3-dioxolane, (4f), and 8.1~ of the starting
material. This product mixture was combined with
those of three other similar runs and separated by
distillation on a 0.76 m spinning band column;
2,2,4,5-tetrafluoro-4,5-dichloro-1,3-dioxolane boiled
at 45-46~C; 2,2,4-trifluoro-4,5,5-trichloro-
1,3-dioxolane, ~4f), at 84C; and the starting
5. 15 material, 2,2-difluoro-4,4,5,5-tetrachloro-
1,3-dioxolane (4j), at 115C. Their purities were
greater than 99%. Both infrared and ~-19 NMR
spectroscopy confirmed their structures.
B. ~echlorination of 2,2,4-trifluoro-4,5,5-
trichloro-1,3-dioxolane, (4f).
A 300 mL 3-neck glass flask equipped with
magnetic stirrer, thermometer, Vigreux column with a
dry ice-cooled still head leading to a cold receiver,
trap, a nitro~en tee, and bubbler was charged with
76.7 g ~1.17 gram-atom~) of zinc, 2.6 g (0.019 mole)
of zinc chloridet and 175 mL of propanol. ~he
stirred mixtuxe was heated to 9~C; then 89.6 g
(0.387 mole) of 2,2,4-trifluoro-4,5,5-
trichloro-1,3-dioxolane, (4f), was introduced from a
syringe pump at a rate of 0.~3 mL/minute during 172
minutes. Distillation at a rate of about 15 mL/hour
began 33 minutes after the start of the addition and
continued for 270 minutes; 65 mL of clear, colorless
distillate weighing 84.5 g and con,aining some
propanol was obtained. It was redistilled through a
0.76 m spinning band column with a dry ice-cooled
head. The product distribution was approximately
3 9~ of 2,2,4-trifluoro-1,3-dioxole, (3g), b.p, 10C;
71.7% of 2,2,4-trifluoro-5-chloro-1,3-dioxole, (3f),
b.p. 25-27C; and 24.3% of 2,2,4-trifluoro-4,5-
dichloro-1,3-dioxolane, (4g), b.p. 73C. The
infrared, F-l9 and proton NMR spectra of these
compounds were consistent with the assigned
structures.
Example 16
Alternate synthesis of 2,2,4-trifluoro-
4,5-dichloro-1,3-dioxolane, (4g).
A~ 4,4,5-trichloro-1,3-dioxolan-2-one.
- A creased 3-neck, 300 mL, round bottom flask
equipped with magnetic stirrer, gas inlet tube,
thermometer, and water condenser topped by a dry ice
condenser leading to a trap and scrub~er was charged
with a8. 1 g of ethylene carbonate. The system was
purged with nitrogen and then dry chlorine gas was
introduced while irradiating the reaction vessel with
a 275 watt General ~lectric*Sun Lamp; the amount of
chlorine was sufficient to maintain a yellow color in
the solution. The temperature ranged from 35C
during the initial part of the chlorination and up to
115C during the later part of the 6-hour reac'ion.
The reaction mixture was analyzed by gas
chromatography techniques and, when all of the
4-chloro-1,3-dioxolan-2-one had been consumed, the
reaction was terminated. The product was principally
4,4,5-trichloro-1,3-dioxolan-2-one wi~h lesser
amounts of 4,5-dichloro- and 4,4,5,5-tetrachloro-
derivatives. Two similar runs were made and the
products combined.
Bo Fluorination of 4,4,5-trichloro-1,3-
35 dioxolan-2-one.
*denotes trade mark
~ ~2~
A shaker tube was charged with 113 g of
crude 4,4,5-trichloro-1,3-dioxolan-2-one, 18 g of HF,
and 194 g of SF4. After agitating 10 hours at
200C, the tube was cooled to 0C, and the product
was mixed with ice. The organic phase was separated
; and neutralized by sha~ing witn an aqueous potassium
carbonate solution and then distilled vn a 0.76 m
spinning band column; the first fraction,
2,2,4,5-tetrafluoro-4,5-dichloro-1,3-dioxolane, b.p.
47-48C, was followed by the desired
2,2,4-trifluoro-4,5 dichloro-1,3-dioxolane, (4g),
b.~. ~9-73C. Infrared and F-l9 NMR spectra were
consistent with this structure.
~x~m~le 17
~ 15 Preparation of 2,2,4-trifluoro-1,3-dioxGle,
; ~3g), by dechlorination of 2,2,4-triEluoro-4,5-
dichloro-1,3-dloxolane, (4g).
A 100 mL, 3-neck, round bottom flask
equipped with m~gnetic stirrer, thermometer, Vigreux
still leading to a dry ice-cooled head, cold receiver
and trap, was charged under a nitrogen blanket with
3.6 g of magnesium turnings, 0.2 g of mercuric
chloride, 0.1 g of iodiner and 30 mL of
! tetrahydrofuran. The mixture was stirred and heate~
to 67C; 8~8 g of 2,2,4-trifluoro~4,5-dichloro-
1,3-dioxolane, (4g), was then added at a rate of
0.092 mL/minute. After 2~ mL had been added the
distillation began and continued for 3 hours until 5
mL of distillate was obtained. The cold distillate
was extracted with ice water to remove some
tetrahydrofuran and there remained 4.7 g of prcduct
which was largely 2,2,4~trifluoro-1,3-dioxole, (3g),
b.p. 10C.
This dioxole was purified by gas
chroma~ography; ~he infrared absorbance spectra, and
23
2~
especially the absorbance in the region of 5.6 ~m, as
well as its subsequent polymerization substantiated
the assigned molecular str~cture.
~xamPle l8
A crystalline copolymer of tetrafluoro-
ethylene with 2,2,4-trifluoro-1,3-dioxole, (3y).
A shaker tube was charged ~ith 100 9 of
1,1,2-trichloro-1,2,2-trifluoroethane, 0.8 g of the
dioxole, 0.03 g of bis(4-t-butylcyclohexyl)
peroxydicarbonate, and 10 g of TFE and heated at 55
and 6$C for 4 hours. After separation of the
produc~ and drying, 4.7 q of a whi~e solid polymer
was obtained. A portion of this was pressed at 330C
to give thin, tough, self-supporting, colorless
filmsO The infrared an2 F-l9 NMR spectra showed the
copolymer composition to be 96.0 mole % TFE and 4.0
mole ~ dioxole. Differential Scanning Calorimetry
showed a crystall;ne melting point at 274C.
Exam~le 19
Homopolymer of 2,2,4-trifluoro-1,3-dioxole,
(3~)-
A 10 mL clear, glass vial was charged with
5.7 g of 1,1,2-trichloro-1,2,2-trifluoroethane,
0.001 g of bis(4-t-butylcyclohexyl) peroxydi-
carbonate, and G.5 g of the dioxole, capped securely
and allowed to stand two days on the bench top at
about 25~C exposed to the normal fluorescent light of
the laboratory. A portion of the solution was then
evaporated on a micro salt plate to give a clear,
colorless, self supporting film which was identified
by its infrared spectrum to be the dioxole
homopolymer.
Example 20
An amorphous copolymer of TFE and 2,2,4-tri
fluoro 5-chloro-1,3-dioxole, (3f)O
24
A shaker tube was charged with 100 g of
1,1,2-trifluoro-1,2,2-trichloroethane, 1.7 g of the
dioxole, 0.03 g of bis(4-t-butylcyclohexyl) peroxy-
dicarbonate, and 10 9 of TFE. Polymerization ~as
carried out at 55 and 65C under autogenous pressure
for 4 hours. After separation and drying of the
- product, 1~8 g of a white, solid polymer was
obtained. A portion of this ~as pressed at 300C to
~ive thin, tough, self-supporting, colorless clear
films. The infrared and F-l9 N~R spectra of this
polymer showed it to contain 10.5 mole ~ of the
dioxole and ~9.5 mole ~ of ~FE. Differential
Scannin~ Calorimetry showed a Tg of 61C, there ~as
no melting point.
! 15 Example 21
An amorphous, elastomeric terpolymer of TFE,
2,2,4 trifluoro-5-chloro-1,3-dioxole, (3f), and
vinylidene fluoride.
~ shaker tube was charged with 100 9 of
1,1,2-trichloro-1,2,2-trifluoroethane, 2.1 g of the
dioxole, 0.03 g of his(4-t-butylcyclohexyl) peroxydi-
carbonate, 6 g of vinylidene fluoride, and 6 g of
TFE. Polymerization was carried out at 55 and 65C
over a 4 hour period under autogenous pressure.
After separating and drying, there was obtained ~.5 g
o white, solid polymer granules. A portion of this
polymer was pressed at 200C to give thin, elastic,
tough, self supporting, clear, colorless films.
Infrared and F-l9 ~MR spectra showed the terpolymer
to consist of 27.7 mole % of TFE, 9.9 mole ~ of the
dioxole and 6204 mole ~ of vinylidene fluoride.
- Differential Scanning Calorimetry showed no meltin~
point~ thus indicating an amorphous polymerO
~5
~t3~
26
Example 22
Synthesis of 2,2-difluoro-1,3-dioxole, (3h).
A. 4,5-Dichloro-1,3-dioxolan-2-one
A 500 mL, 3-neck round-bottom flask equipped
with a nitrogen purge line, magnetic stirrer,
thermometer, and reflux condenser leading to a trap
and drying tower was charged with 88 g of ethylene
carbonate, 297 g of sulfuryl chloride, and la 0 g of
azobisisobutyronitrlle. After purging the assembly
with nitrogen, the stirred mixture was irradiat2d
with a Hanovia mercury vapor lamp at a temperature of
34-47C during the first 3 hours of the reactionO
During the next 7 hours, the temperature was
increased rrorn 51 to 103C. During the final 3
hours of the reaction, the temperature was held in
the 95-107C range.
After cooling to room temperature, the flask
was evacuated on a water aspirator to remove small
amounts of HCl. The flask contents were then
flash-distilled at a pressure of about 266 Pa and a
pot temperature of up to 150C; 85.7 q of distillate
was collected. GC analysis of the distillate showed
it to contain a~proximately 86.3~ of
4,5-dichloro-1,3-dioxolan-2-one, 8.8% of
~-chloro-1,3-d-oxolan-2-one, and 3.1~ of
4,4,S-trichloro--1,3-dioxolan-2-one.
8. 2,2-Difluoro-4,5-dichloro~1,3~dioxolane
(4h)
A 300 mL "Hastelloy'l C shaker tube was
char~ed ~ith 136.2 g o~ 4,5-dichloro~1,3-dioxolan-
2-one, 16.2 g of HF, and 19~.4 g of SF4. The tube
was then heated to 150~C and agitated for 300 hours.
After ~he tube was cooled to 0C, it was slowly
vented and then its contents were dumped into ice.
The organic layer was separated and extracted twlce
26
3,C~ 5
with 50 mL of distilled water. The product weighed
93.0 g and contained about 69~ of
2,2,4-trifluoro-5-chloro-1,3-dioxolane and abollt 7%
of 2,2-difl~loro-4~5-dichloro-
5 1,3-dioxolane, (4h).
C. Dechlorination of 2,2-difluoro-4,5-di-
chloro-1,3-dioxolane (4h)
Equipment like that of Example 15B, except
that a 100 mL flask was used~ was charged with 7.8 g
10 of zinc dust, 0.2 g of zinc chloride, and 40 m~ of
butyl alcohol. The stirred mixture was heated to
114C; 6.5 ~ of crude 2,2-difluoro-4,5-
dichloro-1,3-di~xolane (4h) was -then adde~ ~y a
syringe pump at 0.092 mL/minute over a 52-minute
lS period. Distillation be~an 20 minutes after the
beginning of the addition and continued for 94
min~tes until 4.5 mL of distillate containing some
butyl alcohol was obtained. The distillate was
purified by gas chromatography. The infrared
20 absorbance spectrum, especially the absorbance in ~he
region of 6.05 ~m, was consistent with the
2,2-difluoro-1,3-dioxole structure (3h).
E.Yample 23
Homooolymer of 2t2-difluoro-1,3-dioxole
~3h).
A shaker tube is charged with 3 g of
2,2-difluoro-1,3-dioxole in 100 g of 1,1,2-trichloro-
1,2,2-trifluoroethane, and 0.005 q of
bis(4-t-butylcyclohexyl) peroxydicarbonate.
30 Polymerization is carried out at 55 and 65C for 4
hours. Af~er seParating and drying the solid, white
polymer, 0.6 g, a portion of it is pressed at 250C
to give a tough, clear, transparent, self supporting,
thin film, of the ho~opolymer, which is amorpho~s.
27
r '
~a~
28
Example 24
A crystalline copolymer of
tetrafluoroethylene and 2,2-difluoro-1,3-dioxole,
(3h).
A shaker tube is charged with 1 g of the
dioxole in 100 g of 1,1,2-trichloro-1,2,2-trifluoro-
ethane, 0.03 g of bis(4-t-butylcyclohexyl)
peroxy~icarbonate, and 10 g of TFE. Polymerization
is carried out at 55 and 65C. ~fter separating and
drying the product, 9.9 g of white, granular, solid,
crystalline polymer is obtained. It contains
approximately 93 mole % TFE and 7 mole ~ of the
dioxole.
Exa~Dle 25
` 15 Synthesis of 2,2-difluoro-4-chloro-1,3-
! dioxole, (3i).
This synthesis is carried out in the same
manner as that of Example 22, except that 106.7 9
~0.5 mole) of 2,2-difluoro~4,4,5-trichloro-
lt3-dioxolane, (4i), prepared from
4,4,5-trichloro-1,3-dioxolan-2-one (Example 16A) is
the starting material. Rectification of the product
mix through a 0.76 m spinning band column gives
47~1 9 of 2,2-difluoro-4-chloro-1,3-dioxole, t3i).
~xampl~ 26
A crystalline copolymer of TFE with
2,2~difluoro-4-chloro-1,3-dioxole, (3i).
~ shaker tube is charged with 100 g o
1,1,~-trichloro-1,2,2-trifluoroethane containing 1 g
of 2,2-difluoro-4-chloro-1,3-dioxole, (3i), 0.03 g of
bis(4-t-bwtylcyclohexyl) peroxydicarbonate, and 10 g
of TFE. Polymerization is carried out at 55 and
65C. After separating and drying the product, 5.2 g
of a white solid granular polymer i5 obtained. ~his
is pressed at 300C into a tough, self-supporting,
- 28
, r ~
L~
2g
clear film. The polymer is crystalline and contains
approximately 94 mole % TFE and 6 mole % of the
dioxole.
Exa~ple 27
A Crystalline TFE/2,2-bis(trifl~oromethyl)-4,5-
dichloro-1,3-dioxole, (3e), copolymer
A 110 mL shaker tube was charged with 100 g
of 1,1,2-trichloro-1,~,2-trifluoroethane, 3.0 g of
the dioxole, 0.04 g bis(4-t-butylcyclohexyl)
peroxydicarbonate, 10 g of TFE and heated 3.5 hours
at 55 and &5C under autogenous pressure. After
separation and drying the product, ~.3 g of a white
solid polymer was obtained. Differential thermal
analysis showed a crystalline melting point at 312C;
the infrared spectrum of a film possessed the
, absorbancies characteristic of the
TFE/2,2-bis(trifluoromethyl)-4,$~dichloro-1,3-dioxole
copolymer/ By elemental analysis, the copolymer
contained 0.44~ chlorine which corresponds to 0.6
mole percent of dioxole.
Exa~ple 28
Synthesis of 2,2-difluoro~4,5-dichloro-1,3-dioxole,
(3j)
A. Tetrachloroethylene Carbonate
2~ A 1000 mL creased flask equipped with a
stirrer, thermometer and gas inlet tube, and topped
by water and dry ice condensers, was charged with
352.4 g (4 moles) of melted ethylene carbonate. The
system was purged with nitrogen while ethylene
carbonate was stirred and heated to 50~C. After
turning off the nitrogen, chlorine was introduced at
a rapid rate and when the solution turned yellow~ a
sunlamp was lit. The flow of chlorine and the
intensity of the light were adjusted so that the
solution remained yellow and the temperature did not
29
e~ceed 80C during the first few hours of the
cnlorination. Later on, the temperature was
increased to lQ0 120C.
The chlorination was continued until
intermediates were no longer present in the product,
as evidenced by periodic gas chromatographic
analysis. When the product was free of the mono-,
di-, and trichloro intermediates, it was distilled at
a reduced pressure on a water aspirator. After the
removal of chlorine and hydrogen chloride, the
1 distillation was continued using a high vacuum pump.
B. 2,2-difluoro-4,4,5,5-tetrachloro-
1,3-dioxola~e t4j)
~ 360 mL "Hastelloy" C shaker tube was
charged with 113 g (0.5 mole) of tetrachloroethylene
carbonate, closed under nitrogen, cooled in ~ry
ice/acetone, evacuated, flushed with nitrogen,
reevacuated and then charged with 18 g (0.9 ~ole) of
HF and 194 g tl.8 mole) of SF4. The tube was then
agitated for 10 hours at 200C. Following ~his, the
2 ~ube ~as chilled in an ice-water bath and then slowly
vented to remove the excess of SF4 and HF. The
product was dumped from the tube into we. ice and
allowed to stand a day. The water-product mixture
was placed in a polvethylene separatory runnel, and
the dioxolane (4j) was withdrawn into a polyethylene
Erlenrneyer flask, weighed~ and stirred one hour with
10 mL of a 30~ ~2CO3 solution in water (the pH of
the aqueous phase must be alkaline). The dioxolane
(4j) was then separated and bottled. The
2,2-difluoro 4,4,5,S-tetrachloro-1,3-dioxolane (4j)
was dried over X2CO3 and distilled at a reduced
pressure priox to use (b.p. 126~C at 101 KPa). Fl9
NMR and IR analyses supported the molecular structure.
3S
31
C. ~echlorination of
2,2-difluoro 4,4,5,5-tetrachloro-1,3-dioxolane, (4j).
A 300 mL, 3-neck glass 1ask eq~ipped with
magnetic stirrer, thermometer, Vigreux column with a
water condenser to receiver, trap to a nitrogen tee
and bubbler was charged with l-propanol, 175 ml.; zinc
dust, 59.3 g; ~inc chloride, 2.0 g. After heating to
reflux, the 2,2-difluoro-4,4,i,5-tetrachloro-1,3-
dioxolane (4j), 74.3 g, was added by syringe pump at
0-33 mL/minute. The addition was complete in 148
minutes. Distillation was begun 40 minutes after the
start of the addition and continued for 6 hours until
72 mL of distillate was collecte~. The prod~ct was
98.7% pure desired dioxole, (3j), at 100% conversion
of the dioxolane; the distillate which containe~ some
propanol was redistilled through a 0.51 m spinning
band column to separate the dioxole, (3j), b.p.
64-65C, at a purity of 98.6~. A 3.66 m x .0064 m
diameter 30% Krytox* perfluoroether (Du Pont Co.)
column at 6~C was used in the analysis. The
infrared spectrum was consistent with the structure.
Example 29
A crystalline TFE/2,2-difluoro 4,5-dichloro-lt3-
dioxole, (3j), copolymer.
A 110 mL shaker tube was charged with 100 g
of l,1,2-trichloro-1,2,2-trifluoroethane, 1.8 g of
the dioxole, 0 04 g of bis(4-t-butylcyclohexyl)
peroxydicarbonate, and 10 g of tetrafluoroethylene
and heated 4 hours at 60-~5C. After separation of
the insoluble product and drying, 2.4 g of a~ite solid polymer
~as ob~ned. Differential Scanning Calorimetry shawed a major
cryst~ll;n~ melting point at 310C and a ~unor one at 297C. F-l9
~ysis sh~ed the copolymer to contain 1.4 m~le ~ of the
~;~xnle (3~). Both the infrared and F-l9 ~ s ectra agreed with
the copolym~r ~u~L~
This application is a division of copending application
Serial;~o. 427 320, filed 1983~av 03.
*denotes trade mark
31
