CA1177090A

CA1177090A - Perfluorodiglycidyl ethers

Info

Publication number: CA1177090A
Application number: CA000399789A
Authority: CA
Inventors: Thomas R. Darling; Carl G. Krespan
Original assignee: EI Du Pont de Nemours and Co
Current assignee: EIDP Inc
Priority date: 1981-04-03
Filing date: 1982-03-30
Publication date: 1984-10-30
Also published as: US4363898A; BR8201820A; JPS57176974A; EP0062323B1; DE3262103D1; EP0062323A1

Abstract

ABSTRACT
Perfluoroglycidyl ethers of the formula are prepared by epoxidation of a polyfluorodiallyl ether of the formula CF2=CFCF2ORF.
The glycidyl ethers are useful as monomers for preparing polymers which provide crosslinking or cure sites and are stable elastomeric materials useful as sealants, caulks, and fabricated objects.

Description

~ ~'7'~3 TITLE
Perfluorodiglycidyl ~th~rs and Precursor~ Th~re~or TECHNICAL FIELD
This inventlon relates to per1uorodi~1ycidyl 5 ethers, their prepara~ion and polymer6 therefrom.
BACKt;ROUND ART
P. Tarrant, C. Ç. All;son, R. P.. Barthold and ~. C:. Stump~ Jr ., "Fluorine Chemis~ry Reviews" "
Vol. 5, P. Tarrant, Ed. ~ Dekker, New 5rork, New York (1971) p 77 dlsclose fluorinatea epoxides of the rai formula CF2-~FRF
O
where~n R~, may be a perfluoroalkyl group of up ~o ¦
10 ~arbon~ containing one or more fun~tioalal 15 substituents -CF=CF2, -cb~ F;~, -Cl or -~ I

Oxida~ions of the type CF2 C~CF2X ~ 2 or H2O2/OH ~ C~/CFCF2X are disciosed ~here X is -F, -(CF2)5H (U.5. Patent 3,358,0û3), -CF2C1 or -CF28r (T. I. Ito et al, Abstracts, Div. Fluoro. Chem., ATn. Chem. Soc., 1st ACS/CJS Chem.
Congre~s, Honolulu, E~I, April 1979) 2S Oligomers arK~ polymers of per~luoroepoxide~
CF2-CF-RF are described in U.S. Patent 3,41~,610 and by P. Tarrant et al. in Fluorine Chem. Revi~ws, 5, pp ~6-102 (1971). Nonunct~onal fluoroethers o~
di~luoroacetyl fluoride of the formula RFOCF 2COF
are also kno~m, and the inser'cion of one or more mo}es of hexafluoropropene epoxide inl:o ~aid nonfunctional perfluoroethers is disclosed in ~1~8a ~?atesll: 3 ,250 ,808 CR~8053 35 ~, Rl?~)C~2COF ~ (C~ 5FCF3) ~
o ~ ~ ~
RFOCF2CF20' ~ CE'20-HFCOF (1) ~F3 /n-~ CF3 5 wh~re n i8 1 to at 1 ast 6 and R~
perfluoroalkyl, perfluoroalkoxy, or perfluoroalkoxyalkyl.
Glycidyl ethers containing the ~egment C~2-/ HCH2O- are widely disclosed. The glycidyl C~2-~C~C~2~C6~ is disclosed in U.S. Patent 4,127,615 O DISCLOSURE OF INVENTION
Novel perfluoroglycidyl ethers are provided having the gen~ral formula ~F2-&FcF2 wherein ~ is:
ti) CFR CFQ
y y~
wherein R is a carbon-carbon bond or a linear or bra~ched per~luoroalkylene group of 1 to 12 ~arbon atoms; Q is -OCF2CF=CFz or -OCF2C~F 5F2;

25 -F or -CF3, provided that only one of Y and Y' can be CF3; or (ii) - (CF2CFo)nR3Q

wherein R3 is a linear or branched perfluoroalkylene 30 group of carbon con~ent such tha~ the moiety -(CF2CFo3nR3 does not exce~d 15 carbon atoms; Y inde-p~ndently is -F or -CF3; n is 1 to 4; and Q is as defined above. ~thers of formula I where Q is 35 -OCF~CF=CF2 are useful as intermediates in the preparation of the corresponAing perfluorodiglycidyl ether.

~ ~ '7'~

Perfluoroglycidyl ethers of formula I are prepared by contacting and reacting the corresponding perfluorodiallyl ethers with oxygen.
The ethers of formula I may be homopolymerized, or copolymerized with suitable fluorinated epoxides which include hexafluoropropene oxide, tetrafluoroethylene oxide, and other perfluorodiglycidyl ethers of formula I.
Polymers prepared from formula I glycidyl ethers provide crosslinking or cure sites and are stable elastomeric materials useful as sealants, caulks, and fabricated objects. Preferred are ethers of formula I where RF is -CFRlCFQ or Y Y' -CF2CFOCF2CF2OCFCF2Q; Y and Y' are -F; and Q is -OCF2CF-CF2 .
\J
Perfluorodiallyl ethers, when reacted with 2' also yield, in addition to the perfluoro-diglycidyl ethers of formula I, coproduct fluoroformyl difluoromethyl ethers containing one less carbon a-tom which have the general formula II
wherein RF is as deined above.
The novel perfluoroglycidyl ethers of this invention are prepared from the perfluorodiallyl ethers which are disclosed by Krespan in U.S.
30 Patent No. 4,275,225, issued June 23, 1981. These perfluorodiallyl ethers are of the formula CF2=CFCF20RF
wherein RF is:
(i) -CFR CFQ
Y Y' , ~ ~7i7~

wherein Rl is a carbon-car~on bond or a linear or branched perfluoroalkylene group of 1 to 12 carbo~
atoms; ~1 is OCF2CF=C~2; Y and Y' are -F or -CF3, provided that only one of the Y and Y' can be C~3; or (CF2CFO) nR3Q

wherei~ R is a lin2ar or bran~hed perfluoroalXylene group of carbon c~ntent such that the moiety 10 -(CF2CFo)nR3 does not exceed 15 carbon atoms; Y is y F or -CF3, n i~ 1 to ~; and ~ i~ as defined above.
The perfluoroglycidyl ethers of thi~ invention are also prepared from perfluorodiallyl ethers of the 15 formula CF2--CFCF20 (CF2CFO) nR3Ql wherein R3, Ql, and n are as defined under (ii) above, and Y, independently, can be -F or -CF3.
. These perfluorodiallyl etherx are prepared by (1) mixing and reacting ~a) a carbonyl oompound having the ormula:
o Al-C-Y
wherein Al is Q'CFRl-~' where Rl is a carbon-carbon bond or a linear ox ~ranched perfluoroalkylene gxoup o~ 1 to 12 carbon atoms, Q'i~
-OCF2~F=CF2; Y anQ Y' are -~ or -CF3, provided that only one of Y and Y' can be -CF3; or ~b) a ~arbonyl compound having the formula: !

7'~

,. ........................................... .
A -C-F
wherein A2 is QlR3(ocFcF2)n-locF
Y Y
where R3 is a linear or branched per-fluoroalkylene ~roup of carbon content such that the moiety R3(0CFCF2)n lOCF-Y
does not exceed 14 carbon atoms; Y
independently is -F or CF3; n is 1 to 4; and Q' is defined as above;
with a metal fluoride of the formula MF
where M is K-, Rb-, Cs-, or R4N- where each -R, alike or different, is alkyl of 1 to 6 carbon atoms; and

(2) mixing the mixture from (1) with a perfluoroallyl compound of the formula CF2=CF-CF2 Z
wherein Z is -Cl, -Br or -OSO2F.
I'he perfluoro~lycidyl ethers of formula I and the fluoroformyl difluoromethyl ethers of formula II are prepared from the perfluorodiallyl ethers by partial or complete reaction with oxy~en at about 20 to about 200C, preferably about 80 to about 160C:
o CF2=CFCF2O.RF ~ (2) (x) C\2/CFCF2ORF + (y) FOC-CF2ORF + (y) COF2 o I II
where x and y are, respectively, the mole fractions of products I and II, and RF and RF are defined as above. Ethers of formula I are normally stable at the reaction temperature. Formation of ethers of .~/

'7~

~ormula II, together with carbonyl fluoride, is presumed to result from oxidative cleavage of an allylic double bond in the ~tarting perfluorodially~
ether. Th~ by-product COF2 is normally inert.
The epoxidation reaction may be carried out at pre~sures of about 5 ~o about 3000 p5i, preferably about 50 to about 1500 psi. 5O1vents are not L
esse~tial, but inert diluents such as 1,1,2-trichloro-1,2,2-trifluoroethane (CFC12CF2Cl) or perfluorodimethylcyclobutane may be used.
Reac~ant proportions may vary ~rom a large molar excess of olefin over 2 (e.gO, lOOol) ~o a large exceqs of O~ over olefin (e.g., 100:1); a modest excess o 2' e.g., about 1.1:1 to about 10:1, is normally preferred to insure complete reaction o the olefinO When prepari~g a perfluoroglycidyl ether of fo~mula I wherein Q is -OCF2C~=CF2, the reaction of the starting diolefin with 2 should be run with at least a 2:1 molar excess of dio}efin o~er 2~ and further addition of 2 should be a~oided.
The epoxid~tion reaction is ~ost conveni~ntly initiated thermally, but may be catalyzed by the use of ~ree-radical ini~ia~o~ or by ultraviole'c irradia . ion in the presem:e of a pho~oact.ive material ~uch a~ bromine. The epoxidation may be conducted in a batchwise or continuous manner.
The epoxidation product o formula I ~s generally isolated by direct fractional distillation, 30 althou~h in solDe cases a prelimirlary treatment with Br2 or C12 may be helpful., When ~poxidation i~
~arried out at lower te~perature~ 5 1000), adaition of radical acceptor s ~u~h as o-dichlorobenzene to the mia~ture just prior to fractionation is a desirable 3s precautivn against the possible pre~en~e of peroxides.
Perf luoroalvcidvl e~her~ of formula can be homopolymerized or copolymerized with suitable 7~

fluorinated epo~ides such as HFPO, tetrafluoroethylene epo~ide (TF~O), other perfluoroglycidyl ethers of formula I and perfluoroglycidyl ethers disclosed in the copending Canadian Patent Application No 399,788 of C.G. Krespan et al, filed simultaneously herewith;
HFPO and TFEO are preferred comonomers with HFPO most preferred. (Co)-polymerization proceeds in the presence of a suitable solvent and initiator a~ temper-atures o~ about -45 to about ~25~C, preferably about -35 to about 0C. The quantity of solvent may be from about 5 to about 40 mole percent of the total monomer feed. Suitable solvents include commercial ethers such as diethyl ether, di~lyme, triglyme and tetraglyme (di-, tri-, and tetraethyleneglycol dimethyl ether), and fluorinated solvents such as 1,1,2-trichlorotri-fluoroethane, chlorotrifluoroethylene, dichlorodi-fluoromethane, hydrogen-capped HFPO oligomers of the formula CF3CF2CF2O[CF(CF3)CF2O]nCHFCF , where n is 1 to 6, dimers and t~imers of hexafluoropropene (~IFP), and HFP itself; the latter is a preferred solvent.
Solvents should be thoroughly dried, preferably by means of molecular sieves, before use.
Catalysts suitable for the (co)polymerization of formula I ethers include anionic initiators which are effective for the polymerization of hexafluoro-propylene oxide (HFPO), such as carbon black or, preferably, combinations CsF-LiBr, ~F-LiBr, (C6H5)3PCH3, -LiBr, CsF-FOCCF(CF3)OCF2CF2OCF(CF3)COF, CsF-cF3cF2cF2o[cF(cF3)cF2o~ncF(cF3)coF~ where n is 2 to 6; the latter catalyst wherein n is ~ to 6 is preferred. Preparation of fluoropolyethers such as that used in the last mentioned catalyst is described in U.S. 3,322,826. Catalyst concentration should be about 0.05 to about 1 mole percent of the total ~77C~

monomer feed when higher molecular weight products are desired.
The perfluoroglycidyl ethers of formula I a~d comonomers such as HFPO should be reasonably pure and dry before ~co)polymerization. Monomers may be dried with molecular sieves or, preferably, over KO~I-CaH2.
Dryness and high purity are necessary for the prepara-tion of high molecular weight (co)polymers from formula I ethers.
Polymerization pressures may be in the ranye of from less than one atmosphere to about 20 atmo-spheres or more; pressures in the vicinity of one atmosphere are normally preferred.
The copolymerization of the perfluoroglycidyl ethers of formula I with HFPO, TFEO and other per-fluoroglycidyl ethers can be a random copolymerization whereby the various monomers are added and reacted with one another simultaneously, or the copolymerization can be sequential, i.e., the perfluorodiglycidyl ethers of 0 formula I wherein Q is -OCF2CF-CF2 can be subsequently \0~
copolymerized with material previously polymerized, such as hexa1uoropropylene oxide homopolymers as disclosed in copending Canadian Patent Application No.
399,790 of T.R. Darling filed simultaneously herewith and hexafluoropropylene oxide/perfluoroglycidyl ether copolymers as disclosed in the aforementioned copending Canadian patent application of C.G. Krespan et al.
Such a sequential copolymerization can serve as a specialized form of chain extension.
In the following examples of specific embodi-ments of the present invention, parts and percentages are by ~eight and all temperatures are in degrees C
unless otherwise specified. The most preferred polymer of the present invention is that of Example 9.

~7~ 3~

E ~ MPLE 1 Perfluoro-lf2-epoxy 13,14--epoxy-4,11-dioxatetradecane and Perfluoro-12,13-epoxy-

3,10-dioxatridecanoyl Fluori2e 5 ~CF2'cFcF20cF2cF2cF2~2--~ (C~2~CFcF20cF2cF2cF2~2 o .. I
t CF2CFCF2O(CF2)6OCF2COF (4) O
A sam~le o~ perfluoro-4,11-dioxate~radeca-1,13~diene (51.7 g, 0.087 mol, purified by distilla ion from conc. H2SO4) was diluted to 75 ml with dry CFCi2CF2C~ loaded into a 100-ml stainless steel tube and heated at 140 while 2 lS was injected in 50 psi increments. The maximum pressure was 500 psi, at which point 2 consumption ceased as judged by lack of pressure drop.
Distillation of the liquid products gave 39.1 g of fractions with bp 56 (g5 mm) - 81 (8.0 mm~.
20 Analysis b~ gc revealed a single major peak ~or all fractions with a total of 5-15% of varying lmpurities present. However, IR and NMR ~howed tha~. this main peak r~presented both products. An early ~xactlQn, 6.4 g, bp 62-64 (9 mm)~ was nearly pure 25 perfluoro-12,13-epoxy-3,10-dioxatridecanoyl fluoride. IR ~CFC12CF2Cl): 5.28 (COF), 6.59 (epoxide), 7.5-9.5~ (CF~ C-O). NMR (CC14/CFC13):
9F 13.1 (m, 1~, COF~, -77.2 (~ of d, 3~F 1176~
2~5 Hz, 2F, CF2COF), -83.3 ~m, 4F, CF~O~ 9 -122.5 30 (m, 4F, CF2), -125.8 (m, 4F, CF2~, and -156.7 ppm ~ JFF 18 ~z, lF, CF) with AB groupings for ring CF~ at -103901 and -10433 Hz ~d of t, J~ 18.8, 9c~ Hz, lF) and -10617 and -10659 Hz (d, JFF 17.4 ~z, lF), and or CF2 adjacent to epoxide ring at 35 -7369, -7523, -7553, and 7706 ~z [m, 2F), 7~.3~ ~

~ igher-boilin~ ~uts, 21.8 9, bp mainly 68-70 (8 mm), contained chiefly diepoxide with epoxyacid fluoride as a major impurlty. These higher cuts ~ere combined and shaken with 200 ml sf cold 5 water for 5 min. ~eat of reaction, cloudiness and ~ome foaming were apparent. A portion of the lower layer was dried over anhydrous CaSO4. It was the~ _ transferred trap-to trap twice under vacuum to give

4.26 9 of clear colorless perfluoro-1,2-epoxy-13,14-10 epoxy-4tll~dioxatetradecane~ 99% pure by gc. IR
(neat~: 6.59 (epoxide) and.7.5-9.5~ (CFg C-0) with no bands for OH, C- t or C=C detected. NMR
tCC14/CFC13): 19F -83.5 (m, 4F, CF~0), -122.7 (m, 4F, CF2), ~12509 (m, 4F, CF2), and -15~.9 ppm 15 (t~ JFF 18 Hz, 2F, CF) with AB groupings for ring CF2 at -10391 and -10658 Hz ~d, JFF 17.4 ~z, 2F) and for CF2 adjacent to epoxide ring at -7378, -7531, -7561, and 7714 Hæ ~m, 4F) with only trace impuri~i es present.
Anal- Calcd for ~12F224 C~ 23-02 Found: C, 23.68.
I~ is considered probable that the epoxidation reaction proceeded via the allyloxy-epoxide intermediate C~-CF CF2O(CF2)6OCF2CF=CF2.
O
~XAMPLF 2 Perfluoro~1,2-epoxy-15,1.6-epoxy-S,ll-dimethvl-4,7,10 13-tetraoxahexadecane OCF3 ~F3 n~
2 C F 2 ~ CF C F 2 OS 2 F

A ~uspension of 20.3 g tO.35 mol) o flame-dried KF in 300 ml of dry diglyme while s~irred at 0-5 while 53.~ g (0.125 mol) o per~luoro(2,7-dimethyl 3,6-dioxasuberoyl) fluoride was added. The mixture was stirred for 30 min, af~er which 80.5 9 (0.35 mol) of perfluoroallyl fluorosulfate waC added at 0-5. Af~er having stirred for 3 hr at 0-5, tben at 25 for 2 hr~ the mixture was poured into lQ of cold water. The lower layer was washPd with 500 ml of water, dried over CaSO4 and fractionated to afford 47~3 g ~52%) of pure p~rfluoro~6,11-dimethyl-4,7,10,13-tetxaoxahexadeca-1,15-diene). IR ~neat). 5.58 (C=C), 8-g~ ~CF, C-O). NMR (CC14/CFCC13): 19F -72.1 (d of ~ of d of d, JFF 24.7, ~13.7, 13.7~ 7.3 Hz, 4F, OCF2C=), -30.7 (m, 6F, CF3), -84.1 (m, 4F, OCF ), -92~1 (d o~ d of t, JFF
~z, 2F, cis-CF2CF=CFF~), -105.5 (d of d of t, JFF
118.0, 52.6, 24.7 Hz, 2F, trans-CF2CF=CF~F), -146.0 (~ JFF 21.3 Hz, 2F, CF), and -190.9 ppm (d of d of t, JFF 118.0, 39.4, 13.7 Mz, 2F, -CF2C~=CF2), wi~h an AB pattern for OCF2 at ~7988 t -8122, -8142, and -8258 Hz ~m, 4F).
A~al. Calcd- for C14F26~4 C, 23-15 Found: C, 23.29.

' 2 B.(CF2~CFCF20CF2CFOCF2~2 ~ (cF2~FcF2ocF2cFocF2~2 O l6) + CF2CFCF20CF2CFOCP'2CF2C)CFCF20CF2CF
O I .

~ ~7t~ $~

A ~olution o~ 45.7 9 (00063 mol) o~ the above hexadecadiene in 75 ml of CFC12CF2Cl w~s heated at 140 in a 100-ml stainless steel-lined tube while oxygen was injected portionwise until react~on

5 was complete. Distillation of ~he liquid product afforded 37.2 g of fractions with bp 63 (10 mm~-65~ l (4 mm) ~hown by IR and ~MR to be perfluoro(l,2-epoxy- L
15,16-epoxy-6,11~dimethyl 4,7,10,13-tetraoxahexadecane containing perfluoro(l4~15-epoxy-S,10-dimethyl-10 3,6,g,l2-tetraoxapen~adecanoyl) fluoride as the major impurity. Several fractions (22.7 g) were combined and contacted with Ca~2 while s~anding open ~o atmospheric moisture for a day. The open mixture was then stirred for 4 hr and filtered. Volatiles were transferred at 50 (0.05 mm), stirred with CaS04 for 2 hrs, and then transferred again at 45 (0.05 mm) to give 5.5 g of nearly pure diepoxide. IR
(neat): 6.47 (epoxide) and 8-9~(CF, C-O~ with very weak impurity bands present at 5.28 (COF) and 6.64 (CO2H).
Other fractions were shown by 19F NMR to contain about 8.2 g of diepoxide as 80~ pure material, for a total o 13.7 9 (29~).

Perfluoro(1,2-epoxy-10~ epoxy-4,8~dioxaundecane) ~2 (CF:2=CFCF2aCF2~2ÇF2 ~ (C~2~FCE'20CF2~2CF2 (7), o A 100-ml metal tube containin~ 107 g ~0~24 mol~ of perfluoro(4,8-dioxa-1,10-un~ecadienel was heated at 140 while oxygen wa~ in~ected portionwise until reaction was nearly complete. Fractlonation of the iiquid product~ gave 66.7 g, bp 42-64 (50 mm), containing mainly die~oxide and epoxyacid fluroide.
This distillate was irradiated with excess bromine to remove any olefinic material, residual bromine was evaporated, and the residue was shaken with a mixture of 250 ml of ice water and 50 ml of CFC12CF2Cl.
The organic layer was dried over CaS0~ and _ distilled to give 27.5 9 of nearly pure diepoxide, bp 60-Ç8 (100 mm). The distillate was treated wi~h CaS04, filtered and redis~illed to give 19.6 9 (17%) of pure d~epoxide, bp 54-56 (50 mm). IR
(CCl~CFC12CF2Cl): 6.49 (epoxide), 8-9~ ~CF, C-O). NMR (CC14/CFC13)o F -84.2 (m, 4F, OCF2), -13001 (s, 2F, CF2), and -157.1 ppm (t, JFF 17.5 H~, 2F, CF) with AB pa~terns for C~2 adjacent to epoxide ring at -7399, -7550, -7594, and -7747 ~z ~m, 4F) and for ring CF2 at -10415 and -10457 (d of t, JFF 18.7, 9.7 ~z, 2F) and -10643 and -10584 H. ~d, JF~ 16.4 ~æ, 2F).
Anal. Calcd. for CgF1604: C, 22-71; F~ 63.85.
Found: C, 22.9~; F, 63.92.

:~ 7~7~

YXAXPL~ 4 Copolymerization of Perfluoro(1,2-epoxy-15,16-epoxy~

6,11-dimethyl-4,7,10,13-tetraoxahexadecane) with ~exafluoro ro lene Oxide ~ ~_ The polymerization catalyst was prepared by reacting 2.09 9 (0.0137 mol) C~F, 6.07 9 (0.0273 mol) tetraglyme and 7.97 g (0.01~0 molj :EIFPO tetramer.
The catalyst was shaken for at least S h and centrifuged for 30 min at 0. To a thoroughly dried 4-neck 500-ml fla~k was injected 4 millimole of the prepared catalyst. The reac~ion mixture was then cool~d ~o -35C. ~exafluoropropylene (dried by passing through molecular sieves) was added at a rate of 1 g/min for a total of 20 9.
4.97 g of the diepoxide of Example 1 and 144 g of HFPO (dried by passin~ over KOH and Ca~2) were copolymerized over a period of 35.3 hr at -34 to -35O After this period, the stirring was ~xtremely difficult due to tbe almost semisolid condition of the polymer. Part of the recovered polymer, 15 g, was reacted with 10% NaO~ in ethyl carbitol to a neutral point with phenolphthalein indicator. ~he sodium salt was decarboxylated by heating to 160 for 30 min. The isolated polymer gave ~inh of 0.1~5 in Freon~ E3 [F~CFCF2~3CHFCF3~o The calculated mole~ular weight is 200,000. Based on the 3.34% by weight of added diepoxide, the ratio o~ HFPO unit~
to diglycidyl monom~r units is approximately 132:1.

~ ~ ~ 7~

Terpolymerization of Per1uoro~ epoxy-15,16-epoxy-6,11-dimethyl-4,7,10,13-tetraoxahexadecane) and Perfluoro-6,7-epoxy-4-oxaheptanenitrile with _ _ Rexafluoropropylene Oxide Two monomers were combined as ~ollows: 2 g of ~he diepoxide of Example 1 were mixed with 4.67 g of the epoxynitrile. Following the procedure ~or ~FPO copolymerization ~Example 4), 6.34 g of the 10 mi~ed monomers and 177 g of HFPO were copolymerized at -33 to -35 over a period of 42.3 hr. The molecular weight by inherent viscosity was 41,000.
On standing at room temperature over a period of 3-1~2 months, there was further curing of the polymer 15 re5ulting in a partially solidified material. From the weight % added monomers the ratio of HFPO units to nitrile monomer units to diglycidyl monomer units is approximately 431:8~

Curing of Terpolymer of Perfluorotl,2-epoxy-15,16-epoxy-6,11-dime~hyl-4,7,10-13-tetraoxahexadecane), Perfluoro-6,7-epoxy-4-oxahep~anenitrile and XexafluoroproPylene Oxide ____ _ The f~llowing was milled until a homogeneous 25 mix was obtained: 5.46 g of the terpolymer of Example 5, 0.55 g carbon black, 0.16 9 tetraphenyltin and 0.16 g magnesium oxide. The milled material was degassed by placing in a vacuum oven for 16 hr at 50. This was then placed in a microtensile bar mold 30 and pressed in a Carv~r* press under 500 psi at 210 for 4 hr. At this point a soft rubbery tensile bar was obtained.

35 *denotes trade mark

7'1'~3~3 ~XAMPLE 7 Copolymerization of Perfluoro(1,2-epoxy-10,11-epoxy-4,8 dioxaundecane) with ~exafluoropropylene _ Oxide Following the procedure for ~FPO
copolymerization (Example 4), 5.78 g o~ the diepoxide o~ Example 3 and 165 g of HFPO were copolymerized over a period of 51.1 h at -34 to -36. The molecular weight by IR was 16,000~ The ratio of ~PO
units to diglycidyl monomer units is approxlmately 82:1 On standing at xoom ~emperature for 3 weeks, there was a visible increase in viscosity.
ExAMæLE 8 Copolymerization of Perfluoro-6,7-epoxy-4-oxaheDtanenitrile with Hexafluoropropylene Oxide ~ he polymerization vessel consisted of a fully glass jacketed four-neck rownd bottom reactor which is equipped with a paddle stirrer, Dry Ice reflux condenser, gas inlet port and a thermocouple well. The entire reactor was dried thoroughly at 200C in a dry nitrogen atmosphere and was assembled and kept dry with a blanket of high purity dry nitrogen. Methanol was used as a coolant and was pumped through the coolant jacket from a Neslab ULT80*
low temperature circulator and refrigerator system.
Initiator was prepared by adding, under dry ni~rogen, 7.95 grams (7.8 milliliters, 0.0358 mole) of tetra-glyme to 2.54 grams (0.0167 mole) of cesium fluoride and then adding 2.91 grams (1.75 ml, 0.0068 mole) of 3Q 2,2'-[~tetra~luoroethylene)dioxy]bis-~tetra~luoro-propionyl fluoride). The mixture was shaken overnight at room temperature and then cent~ugedfor 30 minutes to remove unr acted cesium fluoride. With the reactor at room temperature 4 milliliters of initiator 35 was introduced by means of syringe and the reactor was cooled to an internal temperature o~ between ~30 to -34C. ~iquified hexa~luoropropylene was used * denotes trade mark ~t7~9~

as a solvent to dilute th~ cold viscous initiator solution. The polymerization wa carried out at -34C
usi~g the following monomers and dilue~t addition schedule. The approximate addition rates were 5 0.126 g/hr for perfluoro-6,7-epoxy-4-oxaheptanenitrile and 5.7 g/hr for hexafluoropropylene oxide which was puri~ied in a two-stage (potassium hydxoxide/calcium hydride) scrubber and was added as a gas in ~emi-batch fashion.
10 Addition ~FP Curesite HFP0 Time_~hr~ Diluent ~g) Monomer (g) ~g) 0.~3 7 ~ 0 2.67 0 15.2 10.3 1.29 58.7 15 2.~ 30 23.0 2~90 13}.
2.0 30 22.25 _ 2.80 126.8 Total 67 6.99 331.7 EXP~LE ~
Subsequent Copolymerization with Per~luoro-1,2-epoxy-13,14-epoxy-4,11-dioxatetradecane 30 grams of hexafluoropropy}ene (HFP) wexe 25 added to th~ pxoduc~ of ~xample 8 to reduce viscosity and improve mixing of the polymex mass. Then a solution of 1.9 g of diepoxide (perfluoro-1,2-epoxy-13,14-epoxy~
4,11-~ioxatetradecane) in 30 grams of liquid HFP at -40C was added to the reactox over a period of 2 hours.
30 The reactor was maintainP.d at -34C for 24 hours. The polymer was isolated by removing the HFP diluent under ~acuum at --34C and allowing the polymer to warm slowly to room temperature. The polymer mass was protected by a dry nitrogen atmosph~re. The inherentviscosity of the 35 polymer in Freon~ E-3 at 30C was 0 16 dl/g correspond ing to a number average molecular weight of 75,000.
Freon~ E-3 is 2H-hep~adecafluoro-~,8-bis(~rifluoro-methyl)-3,6,9 trioxadodecane.

~L~7t~ 3~

HPat Treatment and Vulcanization o Poly-Hexafluoropropylene Oxide Containin Nitrile Cure Site Th~ polymer prepared as in Example 9 was he~t treated at 14QC/607 Pa for o~e hour, giving a partially gelled polymer~ ~he polymer was washed .
with water on a wash mill for 20 minutes at room temp~rature and was then dried under nitrogen at 10 75C /2.67 kPa for 2 days. Then 41 g of the polymer was milled at room temperature on a roll mill with 1.24 g (3 parts per hundred rubber) of micronized tetraphenyl tin and 6~2 g (15 phr) of SAF carbon black predried under nitrogen 120C/2.67 kPa. The 15 compound was dxied at 92C/2.67 kPa for 3.5 hours, and 5.5 g portions were compression mvlded in a 6~ x 18 x 1.5 mm steel mold a~ 210C and 17 MPa for 2 hours. The cured slabs were removed from the mold at room temperature and were then post cured 20 under nitrogen according to the following schedule:
70~204 6 hrs @204 18 hrs 204~288 6 hrs @288 18 hrs @315 48 hrs Stress-strain properties of a typical vulcaniza~e at room temperature at 100% modulus, MPa1.O
Tensile-at-break, MPa4.6 ~longation-at-break~ % 250 Permanent Se~, % 4 Hardness, ~hore A 30 0-rings prepared by compression molding and post~curing the compound under the above 35 conditions but without the final post-curing at 315 had co~pression set (ASTM D395-78, Method 8) at room temperature/70 hour~ approximately zero percent and at 204/70 hours approximately 40 percent.

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. Perfluoroglycidyl ethers of the formula wherein RF is:
(i) wherein R1 is a carbon-carbon bond or a linear or branched perfluoroalkylene group of 1 to 12 carbon atoms; Q is -OCF2CF=CF2 or ; Y and Y' are -F or -CF3, provided that only one of Y and Y' can be -CF3; or (ii) wherein R3 is a linear or branched perfluoroalkylene group of carbon content such that the moiety does not exceed 15 carbon atoms; Y, independently, is -F or -CF3; n is 1 to 4; and Q is as defined above.

2. A perfluoroglycidyl ether of Claim 1 in which RF is -CF2R1CF2Q wherein Y and Y' are -F and Q
is .

3. A perfluoroglycidyl ether of Claim 1 in which RF is and Q is .

4. The method of preparing a perfluoro-diglycidyl ether of Claim 1 which comprises reacting a polyfluorodiallyl ether of the formula CF2=CFCF2ORF
wherein RF is as specified above, except that Q is -QCF2CF=CF2, with oxygen at 20° to 200°C.