Partially fluorinated polymers and process therefor

Selected partially fluorinated .alpha.,.omega.-dienes can be (co)polymerized to form polymers in which cyclic structures are present. A novel free radical polymerization process, in which the polymer obtained is dependent on the initiator used, is described. The polymers are useful for films, coatings and molded parts.

FIELD OF THE INVENTION 
This invention concerns polymers made from selected partially fluorinated 
dienes, in which the repeat units are cycloaliphatic. Also disclosed is a 
novel monomer, and a free radical polymerization process for making such 
polymers. 
TECHNICAL BACKGROUND 
Free radical polymerizations which include nonconjugated dienes (and bis 
vinyl ethers) usually yield polymers which are crosslinked because of the 
"separate" reaction of each of the double bonds with the free radicals in 
the reactions. However, it is known that in some instances perfluorinated 
or partially fluorinated compounds containing two such double bonds do not 
form crosslinked polymers, but form polymers containing cyclic structures. 
U.S. Pat. Nos. 5,326,917, 5,313,003, 5,260,492, 4,897,457, J. E. Fearn, et 
al., J. Polym. Sci. A-1, vol. 4, p. 131-140 (1966) and D. W. Brown, et 
al., J. Polym. Sci. A-2, vol. 7, p. 601-608 (1969) all describe the 
polymerization of partially or fully fluorinated compounds containing two 
double bonds which give polymers having cyclic structures. The instant 
monomers and polymers are not disclosed therein. 
Commonly assigned U.S. Pat. No. 5,336,741 discloses amorphous, partially 
fluorinated polymers containing selected cyclic units. 
D. J. Burton, et al., J. Fluorine Chem., vol. 50, p. 257-264 (1990) 
describe the synthesis of 1,1,2,3,3-pentafluoro-1,5-heaxdiene. No homologs 
are described. 
SUMMARY OF THE INVENTION 
This patent concerns a polymer, comprising, one or more of the repeat units 
##STR1## 
or one or more of the repeat units 
##STR2## 
This invention also concerns a compound of the formula CF.sub.2 
.dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 CH.dbd.CH.sub.2. 
Further disclosed herein is a free radical polymerization process, 
comprising, contacting, in the liquid phase, CF.sub.2 .dbd.CFCF.sub.2 
CH.sub.2 CH.dbd.CH.sub.2 with a free radical initiator, under conditions 
in which said free radical initiator generates free radicals.

DETAILS OF THE INVENTION 
The compounds CF.sub.2 .dbd.CF(CF.sub.2).sub.n CH.sub.2 CH.dbd.CH.sub.2, 
wherein n is 1 or 2, can be free radically polymerized to polymers 
containing one or more cyclic structures. When n is 2, a polymer with one 
or more of the repeat units (IA), (IB), and (IC) is produced. When n is 1, 
a polymer with one or more of the repeat units (IIA) and (IIB) is 
produced. The synthesis of these two monomers is described in Examples 1 
and 2 and Experiments 1 and 2. 
These monomers may be polymerized by themselves to form homopolymers, or 
copolymerized with other monomers to form copolymers. By "comprising" in 
describing these polymers is meant that they contain the above cyclic 
repeat units, plus any other repeat units from other monomers. Suitable 
comonomers include fluorinated and unfluorinated compounds such as 
tetrafluoroethylene, hexafluoropropylene, vinylidene fluoride, 
perfluoro(alkyl vinyl ether), methyl vinyl ether, propylene, ethylene, 
chlorotrifluoroethylene, and perfluoro(2,2-dimethyl-1,3-dioxole). 
Preferred comonomers are tetrafluoroethylene, perfluoro(propyl vinyl 
ether) and perfluoro(2,2-dimethyl-1,3-dioxole), and tetrafluoroethylene is 
especially preferred. 
The homo- and copolymers described herein are useful for films, coatings, 
and for molded articles. Such items can be made by standard techniques. 
Since these polymers are at least partially fluorinated, they have 
superior chemical resistance, and in many cases superior thermal 
properties. 
The polymerizations described herein may be done by methods well known to 
the artisan, see for instance polymerizations methods described in H. 
Mark, et al., Ed., Encyclopedia of Polymer Science and Engineering, vol. 
16, John Wiley & Sons, New York, 1989, p. 577-648. The polymerizations may 
be done neat, in aqueous emulsion or suspension, in solution or organic 
suspension. They may be done in batch, semibatch or continuous operations. 
A free radical polymerization initiator is used, suitable initiators 
including peroxides such as perfluoro(propionyl peroxide) (3P), 
azonitriles such as azobis(isobutylronitrile) (AIBN), and redox initiators 
such as persulfatebisulfite. As is well known, the process is run at a 
temperature at which the initiator generates free radicals. Process 
temperatures are generally in the range of about -30 degrees C. to about 
200 degrees C., depending upon the initiator selected. 
Although the polymerizations are run in a conventional manner, the results 
of the free radical polymerization of CF.sub.2 .dbd.CFCF.sub.2 CH.sub.2 
CH.dbd.CH.sub.2 (III) gave surprising and very unusual results. FIGS. I 
and 2 show the Differential Scanning Calorimetry (DSC) traces for two 
different homopolymers of (III). The polymer of FIG. 1 was made using AIBN 
as the initiator, as described in Example 9. The polymer of FIG. 2 was 
made using 3P as the initiator, as described in Example 10. These two 
traces show that even though a "homopolymer" is made (there is only one 
monomer present), two different polymers are produced. This is very 
unusual. 
It is hypothesized this result is due to differing relative amounts of 
(IIA) and (IIB) in these two homopolymers, and that this difference is due 
to the differing initiators used. One of the initiators, 3P, is relatively 
(to AIBN) electron deficient, and it is hypothesized this is the cause of 
the differing polymers produced. 
In the Examples, the following abbreviations are used: 
AIBN--azobis(isobutyronitrile) 
DSC--differential scanning calorimetry 
DMF--N,N-dimethylformamide 
FC--75-perfluorobutyltetrahydrofuran 
PDD--perfluoro(2,2-dimethyl-1,3-dioxole) 
PTFE--polytetrafluoroethylene 
TGA--thermogravimetric analysis 
Glass transition temperatures were taken as the beginning of the 
transition, while melting points were taken as the peak of the melting 
endotherm. The heating rate for the DSC was 20.degree. C./min. 
EXAMPLE 1 
Preparation of CF.sub.2 ClCFClCF.sub.2 CF.sub.2 CH.sub.2 CHICH.sub.2 OAc 
To a stirred solution of 20 g of allyl acetate, 10 mL of hexane and 2.0 g 
of Pd(PPh.sub.3).sub.4 was added 56.8 g of CF.sub.2 ClCFClCF.sub.2 
CF.sub.2 I at room temperature. Exothermic reaction occurred and the 
mixture was stirred overnight and then distilled to give 53.5 g of 
CF.sub.2 ClCFClCF.sub.2 CF.sub.2 CH.sub.2 CHICH.sub.2 OAc bp 
89.degree.-90.degree. C./0.3 mmHg. .sup.19 F NMR: -64.0 (m, 2F), -110 to 
-112.8 (m, 2F), -116.1 (m, 2F), -130.8 (m, 1F). .sup.1 H NMR: 4.44-4.28 
(m, 3H), 3.05-2.70 (m, 2H), 2.13 (s, 3H). Anal: Calcd for C.sub.9 H.sub.8 
F.sub.7 Cl.sub.2 IO.sub.2 : C, 22.57; H,1.68; F, 27.77; Cl, 14.80; I, 
26.50. Found: C, 23.01; H, 1.85; F, 28.92; Cl, 14.79; I, 26.08. 
EXAMPLE 2 
Preparation of CF.sub.2 .dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 CH.dbd.CH.sub.2 
To a stirred solution of 10.5 g of Zn and 20 mL of DMF was slowly added 0.5 
g of BrCH.sub.2 CH.sub.2 Br at 80.degree. C. After the mixture was stirred 
for 10 min, 24 g of CF.sub.2 ClCFClCF.sub.2 CF.sub.2 CH.sub.2 CHICH.sub.2 
OAc was slowly added and the resulting mixture was stirred for 2 hours. 
Volatiles (6.8 g) were transferred to a -78.degree. C. trap at 13 kPa 
(absolute) and then redistilled to give 6.2 g of pure CF.sub.2 
.dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 CH.dbd.CH.sub.2, bp 87.degree. C. 
.sup.19 F NMR: -90.7 (ddt, J=55.3 Hz, J=38.1 Hz, J=5.7 Hz,1F), -107.4 
(ddtt, J=112.7 Hz, J=55.3 Hz, J=26.9 Hz, J=3.4 Hz, 1F), -115.2 (tm, J=18.5 
Hz, 2F), -119.6 (ddd, J=26.9 Hz, J=14.5 Hz, J=5.7 Hz, 2F), -188.3 (ddt, 
J=112.7 Hz, J=38.1 Hz, J=14.5 Hz, 1F). .sup.1 H NMR: 5.75-5.90 (m, 1H), 
5.70 (m, 2H), 2.82 (m, 2H). IR: 1789 (s), 1653 (m), 1368 (s), 1318 (s), 
1272 (s), 1108 (s). Anal: Calcd for C.sub. 7 H.sub.5 F.sub.7 : C, 37.85; 
H, 2.27. Found: C, 37.62; H, 2.28. 
EXPERIMENT 1 
Preparation of CF.sub.2 .dbd.CFCF.sub.2 CH.sub.2 CHICH.sub.2 OAc 
A mixture of 27.0 g of perfluoroallyl iodide, 18 g of allyl acetate and 1.4 
g of copper powder was stirred at 48.degree. C. under N.sub.2 overnight. 
The condenser was replaced with a distillation head and the mixture was 
distilled in vacuum to give 31.5 g of CF.sub.2 .dbd.CFCF.sub.2 CH.sub.2 
CHICH.sub.2 OAc, bp 92.degree. C./665 Pa. .sup.19 F NMR: -93.6 (ddt, 
J=60.2 Hz, J=35.8 Hz, J=5.1 Hz, 1F), -99.0 (dm, J=280 Hz, 1F), -103.4 (dm, 
J=280 Hz, 1F), 108.0 (ddt, J=144.9 Hz, J=58 Hz, J=28.2 Hz, 1F). .sup.1 H 
NMR: 4.35-4.20 (m, 3H), 2.88-2.72 (m, 2H), 2.08 (s, 3H). IR: 2958 (w), 
1788 (s), 1749 (s), 1316 (s), 1290 (s), 1172 (s), 1125 (s), 995 (s). 
Anal: Calcd for C.sub.8 H.sub.8 F.sub.5 IO.sub.2 : C, 26.84; H, 2.25; F, 
26.53. Found: C, 26.91; H, 2.27; F, 25.28. 
EXPERIMENT 2 
Preparation of CF.sub.2 .dbd.CFCF.sub.2 CH.sub.2 CH.dbd.CH.sub.2 
To a stirred solution of 6.5 g of Zn and 20 mL of DMF was added 0.5 g of 
1,2-dibromoethylene at 80.degree. C. After the resulting mixture was 
stirred for 20 min, 25.0 g of CF.sub.2 .dbd.CFCF.sub.2 CH.sub.2 
CHICH.sub.2 OAc (Experiment 1) was slowly added over 35 min at 80.degree. 
C. After the addition was complete, the reaction mixture was stirred for 
30 min. Volatile materials (9.6 g, 99.8% pure) were collected in a dry 
ice-acetone trap under partial vacuum (26.6 kPa). Redistillation gave 9.1 
g of CF.sub.2 .dbd.CFCF.sub.2 CH.sub.2 CH.dbd.CH.sub.2, bp 
63.degree.-64.degree. C. .sup.19 F NMR: -95.9 (ddt, J=64.9 Hz, j=36.2 Hz, 
J=5.3 Hz, 1F), -101.7 (m, 2F), -109.7 (ddt, J=114.5 Hz, J=64.5 Hz, J=27.2 
Hz, 1F), -188.9 (ddt, J=115 Hz, J= 36.2 Hz, J=13.7 Hz, 1F). .sup.1 H NMR: 
5.82-5.69 (m, 2H), 5.32-5.27 (m, 1H), 2.86 (td, J=15.8 Hz, J=7.1 Hz, 2H). 
EXAMPLE 3 
Homopolymerization of CF.sub.2 .dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 
CH.dbd.CH.sub.2 initiated by bis(perfluoropropionyl) peroxide 
A 25 mL glass ampul fitted with a PTFE coated stir bar was charged with 0.3 
mL of 5% of bis(perfluoropropionyl) peroxide in 
1,1,2-trichlorotrifluoroethane and 0.8 g of the title compound. The ampul 
was sealed and 10 cooled in a liquid nitrogen bath. After being evacuated 
and purged with N.sub.2 alternately six times, contents of the sealed 
ampul were stirred at 40.degree. C. for 23 hours. The white heterogenous 
mixture was filtered, washed with ethyl acetate, and dried under vacuum at 
100.degree. C. to give 0.36 g of polymer. 
The IR spectrum of this polymer showed no absorption at around 1790 and 
1650 cm.sup.-1 which could be attributed to double bonds in the polymer. 
This polymer was insoluble in acetone, ethyl acetate, tetrahydrofuran and 
DMf, hexafluorobenzene and FC-75. The polymer had a glass transition 
temperature of 113.degree. C., a crystalline temperature of 177.degree. C. 
and a melting point of 260.degree. C. by DSC (second heat). By TGA the 
polymer showed 10% weight loss at temperatures of about 445.degree. C. in 
nitrogen and 410.degree. C. in air, respectively, when heated at 
20.degree. C./minute. 
EXAMPLE 4 
Homopolymerization of CF.sub.2 .dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 
CH.dbd.CH.sub.2 initiated by bis (perfluoropropionyl) peroxide in CFC-113 
A 75 mL glass ampul fitted with a PTFE coated stir bar was charged with 0.8 
mL of 5% of bis(perfluoropropionyl) peroxide in 
1,1,2-trichlorotrifluoroethane (CFC113), 6.0 g of the title compound and 
25 g of 1,1,2-trichlorotrifluoroethane. The ampul was sealed and cooled in 
a liquid nitrogen bath. After being evacuated and purged with N.sub.2 
alternately six times, contents of the sealed ampul were stirred at 
40.degree. C. for 22 hours. The white heterogenous mixture was filtered 
and washed with CFC113 and dried under vacuum at 100.degree. C. to give 
0.25 g of polymer. Anal: Calcad for C.sub.7 H.sub.5 F.sub.7 : C, 37.85; H, 
2.27. Found: C, 36.82; H, 2.17. 
This polymer was insoluble in acetone, ethyl acetate, tetrahydrofuran and 
DMF, hexafluorobenzene and FC-75. The polymer had a glass transition 
temperature of 106.degree. C. and a melting point of 258.degree. C. by DSC 
(second heat), and no crystalline temperature was observed. By TGA the 
polymer showed 10% weight loss at temperatures of about 445.degree. C. in 
nitrogen and 420.degree. C. in air, respectively, when heated at 
20.degree. C./minute. 
EXAMPLE 5 
Homopolymerization of CF.sub.2 .dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 
CH.dbd.CH.sub.2 initiated by AIBN in CFC113 
A 50 mL glass ampul fitted with a PTFE coated stir bar was charged with 90 
mg of AIBN, 6.0 g of the title compound and 10 mL of in 
1,1,2-trichlorotrifluoroethane (CFC113). The ampul was sealed and cooled 
in a liquid nitrogen bath. After being evacuated and purged with N.sub.2 
alternately six times, contents of the sealed ampul were stirred at 
70.degree. C. for 60 hours. The white heterogenous solution were filtered 
and washed with CFC113 and dried under vacuum at 110.degree. C. to give 
3.5 g of polymer. 
This polymer was insoluble in acetone, ethyl acetate, tetrahydrofuran and 
DMF, hexafluorobenzene and FC-75. The polymer had a glass transition 
temperature of 108.degree. C. and a melting point of 260.degree. C. by DSC 
(second heat), and no crystalline temperature was observed. By TGA the 
polymer showed 10% weight loss at temperatures of about 445.degree. C. in 
nitrogen and 420.degree. C. in air, respectively, when heated at 
20.degree. C./minute. 
EXAMPLE 6 
Copolymerization of CF.sub.2 .dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 
CH.dbd.CH.sub.2 with perfluoropropyl vinyl ether (PPVE) 
A 25 mL glass ampul fitted with a PTFE coated stir bar was charged with 20 
mg of AIBN, 2 mL of 1,1,2-trichlorotrifluoroethane, 1.0 g of CF.sub.2 
.dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 CH.dbd.CH.sub.2 and 1.0 g of PPVE. The 
ampul was sealed and cooled in a liquid nitrogen bath. After being 
evacuated and purged with N.sub.2 gas six times, contents of the sealed 
ampul were stirred at 65.degree. C. for 20 hours and 70.degree. C. for 48 
hours. After removal of CFC113, white solids were dissolved in ethyl 
acetate, reprecipitated by addition of methanol containing 20% water and 
dried under vacuum at 100.degree. C. to give 0.38 g of polymer. The 
polymer had a glass transition temperature of 106.degree. C. and a melting 
point of 253.degree. C. by DSC (second heat). By TGA the polymer showed 
10% weight loss at temperatures of about 440.degree. C. in nitrogen and 
420.degree. C. in air, respectively, when heated at 20.degree. C./minute. 
EXAMPLE 7 
Copolymerization of CF.sub.2 .dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 
CH.dbd.CH.sub.2 with PDD 
A 25 mL glass ampul fitted with a PTFE coated stir bar was charged with 
0.35 mL of 5% of bis(perfluoropropionyl) peroxide in 
1,1,2-trichlorotrifluoroethane and 0.6 g of CF.sub.2 .dbd.CFCF.sub.2 
CF.sub.2 CH.sub.2 CH.dbd.CH.sub.2 and 0.6 g of PDD. The ampul was sealed 
and cooled in a liquid nitrogen bath. After being evacuated and purged 
with N.sub.2 alternately six times, contents of the sealed ampul were 
stirred at 40.degree. C. for 23 hours. The white heterogenous solution 
were filtered and washed with ethyl acetate and dried under vacuum at 
100.degree. C. to give 0.63 g of polymer. The polymer had a glass 
transition temperature of 109.degree. C. and a metaling point of 
262.degree. C. by DSC (second heat). By TGA the polymer showed 10% weight 
loss at temperatures of about 445.degree. C. in nitrogen and 410.degree. 
C. in air, respectively, when heated at 20.degree. C./minute. 
EXAMPLE 8 
Copolymerization of CF.sub.2 .dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 
CH.dbd.CH.sub.2 with Tetrafluoroethylene 
A 100 mL shaker tube was charged with 10 mL of 
1,1,2-trichlorotrifluoroethane, 2.5 mL of 5% of bis(perfluoropropionyl) 
peroxide in CFC113, 6.0 g of CF.sub.2 .dbd.CFCF.sub.2 CF.sub.2 CH.sub.2 
CH.dbd.CH.sub.2. After being sealed, the tube was cooled, evacuated and 
pressured with 6 g of tetrafluoroethylene. The contents were shakered at 
40.degree. C. for 15 hours and 60.degree. C. for 2 hours. The suspension 
was filtered and the solids were washed with CFC113 for four times and 
dried in vacuum at 80.degree. C. to give 4.5 g of polymer. The polymer had 
a glass transition temperature of 104.degree. C. and no melting point by 
DSC (second heat). By TGA the polymer showed 10% weight loss at 
temperatures of about 410.degree. C. in nitrogen and 390.degree. C. in 
air, respectively, when heated at 20.degree. C./minute. 
It could be obtained as a colorless and transparent thin film upon removing 
solvent from its solution in hexafluorobenzene spread on a glass plate. 
EXAMPLE 9 
Homopolymerization of CF.sub.2 .dbd.CFCF.sub.2 CH.sub.2 CH.dbd.CH.sub.2 
initiated by AIBN 
A 25 mL glass ampul fitted with a PTFE coated stir bar was charged with 20 
mg of AIBN and 1.12 g of the title compound. The ampul was sealed and 
cooled in a liquid nitrogen bath. After being evacuated and purged with 
N.sub.2 alternately six times, contents of the sealed ampul were stirred 
at 65.degree. C. for 60 hours. The white heterogenous mixture was filtered 
and washed with CFC113 and dried under vacuum at 100.degree. C. to give 
0.13 g of polymer. 
The polymer had a glass transition temperature of 110.degree. to 
184.degree. C. and no melting point by DSC (second heat). By TGA the 
polymer showed 10% weight loss at temperatures of about 440.degree. C. in 
nitrogen and 415.degree. C. in air, respectively, when heated at 
20.degree. C./minute. 
EXAMPLE 10 
Homopolymerization of CF.sub.2 .dbd.CFCF.sub.2 CH.sub.2 CH.dbd.CH.sub.2 
initiated by bis(perfluoropropionyl) peroxide 
A 25 mL glass ampul fitted with a PTFE coated stir bar was charged with 0.3 
mL of 5% of bis(perfluoropropionyl) peroxide in 
1,1,2-trichlorotrifluoroethane and 1.0 g of the title compound. The ampul 
was sealed and cooled in a liquid nitrogen bath. After being evacuated and 
purged with N.sub.2 alternately six times, contents of the sealed ampul 
were stirred at 40.degree. C. for 60 hours. The white heterogenous mixture 
was filtered and washed with CFC113 and dried under vacuum at 100.degree. 
C. to give 0.10 g of polymer. 
The polymer had no glass transition by DSC and temperatures by TGA the 
polymer showed 10% weight loss at temperatures of about 450.degree. C. in 
nitrogen and 415.degree. C. at respectively, when heated at 20.degree. 
C./minute.